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2202L5JE-DA-C5-N_2015.05.

Compound 2-stage Screw Compressor

1612LSC Speed Increaser Type

Instruction Manual

1612LSC-52 ／ 1612LSC-62 1612LSC-53 ／ 1612LSC-63

1612LSC-54

CAUTION

Before operating, servicing, or inspecting this product, read this manual thoroughly to fully understand the contents. Keep this Instruction Manual in a safe, designated place for future reference whenever the manual is needed. Specifications of this product and contents of this manual are subject to change without prior notice due to technical improvements, and the like.

2202L5JE-DA-C5-N_2015.05.

Preface

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

Preface

Thank you for purchasing this

compound two-stage screw compressor 1612LSC speed

increaser type (hereinafter indicated as “this product”). This instruction manual (hereinafter indicated as “this manual”) describes safety information,

operational and maintenance procedures in detail for safe and ef fe ctive use of this product, and applie s to the following types.

1612LSC-*B*-52/62、1612LSC-*B*-53/63、1612LSC-*B*-54 Before installing or using this product, make sure you read this manual. Keep this manual in a safe place near the product for quick reference.

Revision History

Title Document No. First Edition Issue Date

1612LSC Speed Increaser Type

Instruction manual

2202L5JE-DA-C5-N_2015.05. 2013.05.30

Revision

No.

Issue Date Major Contents of Revisions Created / Approved by:

－

1974.06.30

Issuance of 1612C first edition Yamamoto

－

1983.10.01

New issuance as 1612C/2016C edition Yamamoto

－

1993.06.30

Revision of 1612C/2016C (correcting editing errors, etc.)

Yamamoto

－

2006.06.30

2004.07 Re-examination by constitution of Product Liability Act

Ikehara / Shozu

00 2013.05.30

Overall re-examination by reissuance as an electronic edition, its document No. change

Ikehara / Hirao

01 2014.01.15

1.1.1「MSDS」 change to 「SDS」, etc.

Ikehara / Hirao

02 2015.05.12

Modified the constitution of Chapter 4 and Chapter 5. Correction of describing, etc.

Ikehara / Muta

2202L5JE-DA-C5-N_2015.05.

Warranty and Disclaimer

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

Warranty and Disclaimer

Warranty Clauses

MAYEKAWA shall repair or replace parts of this product for no charge if any failure resulting from defects in design or manufacture occurs, under normal use with the purpose and method that are in accordance with the specifications of this product and this manual, within the warranty period.

The warranty period is "12 months from factory shipment of this product". If there is a separate agreement, that agreement shall prevail in principle.

MAYEKAWA is not liable for production or man-made disaster compensation due to malfunction or damage of this product.

Disclaimer of Warranty

Although MAYEKAWA warrants the clauses mentioned above, the following clauses are exempted.

 Malfunction or damage of this product caused by natural disaster, or other accidental forces

(such as fire, thunderbolt, windstorm, intense rainfall, flood, tidal wave, earthquake, land subsidence, etc.).

 Malfunction or damage caused by misusage described below.

 Malfunctions, damage, or deterioration of this product due to abnormal or improper use

(including improperly storing this product outdoors or under too hot/humid conditions, unexpected inspections, tests, operations, too frequent liquid flow-back operation*, and too frequent start-stop cycles, etc.).

 Malfunction or damage caused by devices or equipments not provided by MAYEKAWA

including operation control methods of those devices.

 Malfunction or damage caused by refrigerants, gases, or refrigerant oils, and operating

conditions (design conditions) not approved for this product.

 Malfunction or damage caused by maintenance or inspection not recommended by

MA YEKAWA.

 Malfunction or damage caused by parts that are not

genuine.

 Malfunction or damage caused by remodeling the product without approval of

MA YEKAWA.

 Malfunction or damage caused by unexpected misusage

"Liquid flow-back operation" is ･･･ Normally, while the compressor sucks in the refrigerant liquid only after vaporizing it in the

evaporator, it may directly sucks it in because of the faulty adjustment or failure of the expansion valve. We call this state of compressor operation "liquid flow-back operation".

No compressor can compress a liquid. The compressor may be damaged should the liquid be sucked in.

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Important Information

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

iii

Important Information

Intended Use of this Product

This product is a general-purpose screw compressor intended for refrigeration and cold storage. Do not use the product for any purposes for which it was not intended or which depart from the

specifications. For specifications of this product, refer to “2.3 Compressor Specifications”. The maintenance items described in this manual should be performed safely and closely following

procedures.

Important Information for Safe Use of this Product

Although MAYEKAWA has thoroughly considered the safety measures for this product, all hazards, including potential hazards caused by human error or environmental conditions, cannot be anticipated.

There are many guidelines that must be observed for operating this product. However, the warnings in this manual and the safety labels on the product are not all inclusive. When operating this product, always pay extreme attention to general safety precautions as well as on items described in this manual.

Important rules for safe operation that apply to all workers including managers and supervisors are listed below.

Before using this product, carefully read and fully understand the contents written in this manual and pay attention to safety.

 Operation, maintenance, and inspection of this product should be performed by qualified

personnel educated about the fundamentals of the product and trained about the hazards involved and measures to avoid danger.

 Do not allow anyone other than those educated about the fundamental expertise of the

product and trained about hazards involved and measures to avoid dangers to approach the product while it is operating or during maintenance.

 Observe all related federal/national and local codes and regulations.  To prevent accidents, do not carry out any operation or maintenance other than those

described in this manual, or use the product for any unapproved purpose.

 Replace parts with

genuine parts.

 Not only workers but also managers should actively participate in safety and health activities in

the workplace to prevent accidents.

 When closing or opening valves during work, apply lockout/tagout without failure, to prevent

the valves from closing or opening accidentally during the work.

[Lockout] To lock with a key in order to keep people, except the workers involved, from operating the product.

“Lockout” means disconnecting or keeping disconnected machines and devices by lockin g their energy (power) sources. Lockout is not just simply turning off the power switches to stop the supply of power, but includes immobilizing them with a key or similar device to keep any blocked switches from being operated.

Lockout devices are devices such as keys, covers, and latches, to immobilize switches, valves, opening and closing levers, etc., with a state of being locked.

[T agout] To prevent any inappropriate work by hanging t ag plates indicating “work in progress”.

“Tagout” means to clearly indicate, by hanging tag plates, that a device is in lockout and that operation of the device is prohibited. Tag plates forbidding operation, starting, opening, etc. are warnings clearly stating to not operate energy (power) sources, and are not for stopping blocking devices.

2202L5JE-DA-C5-N_2015.05.

Important Information

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

Observe the following precautions when performing maintenance work on electrical control.

 Electrical maintenance of the product must be performed by certified/qualified personnel and

only by those educated about the electrical control of the product.

 Before servicing or inspecting the electrical equipment or devices, turn off the motor main

power and control power, and perform lockout/tagout to prevent the power from being turned on during work.

Even when the motor main power and control power are turned off, the product may be turned on if power is supplied from outside the package unit in which this product is used. Make sure the power supply on the power source side is shut off, and perform lockout/tagout to prevent this product from being turned on during work.

About This Manual

 This product may be modified without prior notice. Therefore, the appearance of actual

machine may differ from the descriptions in this manual. If you have any questions, contact our sales offices or service centers. For each sight of MAYEKAWA, refer to "Contact Information" in this manual or following URL. http://www.mayekawa.com/about/network/

 This manual is in English. If any other language is required it is the customer’s responsibility to

prepare a manual for safety education and operation instructions.

 This manual is copyrighted. Drawings and technical references including this manual shall not,

in whole or in part, be copied, photocopied, or reproduced into any electronic medium or machine-readable form without prior permission from MAYEKAWA.

 Photographs or drawings included in this manual may differ from the appearance of the actual

product.

 If this manual is lost or damaged, immediately place a purchase order to our local sales offices

or service centers for a new manual. Using the product without the manual may result in safety issues.

 If you resell the product, never fail to include this manual with the product.

Construction of This Manual

Title of section and chapter Description details

Preface Describes the outline of this manual and how to use it. Warranties and Disclaimer

Describes what MAYEKAW

warrants and what are covered by the

warranties. Warranty exemption is stated as disclaimer.

Important Information

Describes important information related to this product and this manual.

1. Safety

Describes workers' safety information, safety measures taken for this product, and administrative control on industrial safety which is required when handling this product.

2..Compressor Specifications and Structure

Describes main components of this product and their functions, specifications and operating limits.

3. Installation Describes procedures for installing this product.

4. Compressor and Package Unit Operation

Describes precautions for using this product.

5. Maintenance and Inspection

Describes inspection locations & frequency and assembly & disassembly of this product.

6. Troubleshooting

Regarding major troubles that may occur during use of this product, describes how this product will act as well as what actions should be taken when a trouble may occur.

7. Related Documents Shows materials such as exploded drawings and part s list.

Contact Information

Provides contact information for our sales offices and service centers which is to be used for purposes such as genuine parts ordering.

2202L5JE-DA-C5-N_2015.05.

Table of Contents

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

Table of Contents

Preface .................................................................................................................... ⅰ

Revision History ..................................................................................................... ⅰ

Warranty and Disclaimer ....................................................................................... ⅱ

Important Information ............................................................................................ ⅲ

Intended Use of This Product ........................................................................................... ⅲ

Important Information for Safe Use of This Product .......................................................... ⅲ

About This Manual ............................................................................................................. ⅳ

Construction of This Manual .............................................................................................. ⅳ

Table of Contents ................................................................................................... ⅴ

1 Safety

1.1 Strict Requirements and Prohibitions ........................................................ 1-1

1.1.1 Strict Requirements (Do's) ................................................................................... 1-1

1.1.1.1 Do's on Operation ........................................................................................ 1-1

1.1.1.2 Do's on Maintenance ................................................................................... 1-1

1.1.1.3 Do's on Lockout/Tagout after Shutting Off the Power ................................. 1-1

1.1.1.4 Do's about Personal Protective Gear .......................................................... 1-2

1.1.1.5 Do's about the Handling of Hazardous and Toxic Substances .................... 1-2

1.1.1.6 Do's about Handling Emergency Situations ................................................ 1-2

1.1.1.7 Do's about Waste Oil, Fluid, and Materials ................................................. 1-2

1.1.1.8 Other Do's .................................................................................................... 1-2

1.1.2 Prohibitions (Don'ts) ............................................................................................ 1-3

1.2 Warnings ....................................................................................................... 1-3

1.3 Residual Risks ............................................................................................. 1-4

1.4 Safety Devices .............................................................................................. 1-6

1.4.1 Emergency Stop Button ....................................................................................... 1-6

1.4.2 Breakers for the Main Motor Power and Control Power ...................................... 1-6

1.4.3 Compressor Protection Devices .......................................................................... 1-7

2 Compressor Specifications and Structure

2.1 Overview of the Compound 2-stage Screw Compressor

1612LSC Speed increaser Type .................................................................. 2-1

2.2 Model Designation of the Compressor ....................................................... 2-1

2.3 Compressor Specifications ......................................................................... 2-2

2.3.1 Standard Specifications ....................................................................................... 2-2

2.3.2 Operation Limits ................................................................................................... 2-3

2.3.3 Outer Dimensions ................................................................................................ 2-4

2.4 Structure of Compressor ............................................................................ 2-5

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Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

2.5 Mechanisms ................................................................................................. 2-6

2.5.1 Basics of the Screw Compressor ........................................................................ 2-6

2.5.2 Suction Process ................................................................................................... 2-6

2.5.3 Compression Process .......................................................................................... 2-7

2.5.4 Discharge Process ............................................................................................... 2-7

2.5.5 About Volume Ratio (Vi) ...................................................................................... 2-7

2.5.6 Capacity Control Mechanism ............................................................................... 2-9

2.5.7 Bearings and Balance Piston .............................................................................. 2-9

2.5.8 Shaft Seal ............................................................................................................ 2-9

2.6 Gas and Oil Flow ........................................................................................ 2-10

3 Installation

3.1 General Precautions for Installation ......................................................... 3-1

3.2 Installation Works ........................................................................................ 3-1

3.2.1 Unpacking ............................................................................................................ 3-1

3.2.2 Storage ................................................................................................................ 3-1

3.2.3 Transportation ...................................................................................................... 3-1

3.2.4 Preparation for Installation ................................................................................... 3-4

3.2.5 Installation .................................................................................................. 3-5

3.2.5.1 Installation .................................................................................................... 3-5

3.2.5.2 Shaft Alignment between Compressor and Driving Machine ...................... 3-5

3.2.5.3 Piping Connection ....................................................................................... 3-6

3.2.5.4 Equipment and Devices for Protection of the Compressor ......................... 3-6

3.2.6 Airtightness Test .................................................................................................. 3-7

3.2.7 Lubricating Oil Charge ......................................................................................... 3-7

3.2.7.1 Initial Charge of Lubricating Oil ................................................................... 3-7

3.2.7.2 Additional Charge of Lubricating Oil ............................................................ 3-7

3.2.8 Charge of Refrigerant .......................................................................................... 3-7

3.2.9 Check after Installation ........................................................................................ 3-7

4 Compressor and Package Unit Operation

4.1 Lubricating Oil (Refrigerant Oil) ................................................................. 4-1

4.1.1 Precautions for Selecting the Lubricating Oil....................................................... 4-1

4.1.2 Recommended Lubricating Oils .......................................................................... 4-1

4.1.2.1 Recommended Lubricating Oils for Ammonia Refrigerant .......................... 4-1

4.1.2.2 Oils for Systems using Hydrofluorocarbon (HFC) Refrigerants .................. 4-2

4.1.3 Change of Lubricating Oil Brand ......................................................................... 4-3

4.1.4 Precautions for Handling Lubricating Oil ............................................................. 4-4

4.1.4.1 Precautions for Handling Polyalkylene Glycol (PAG) .................................. 4-4

4.1.4.2 Precautions for Handling Polyolester (POE) Oil .......................................... 4-4

4.1.5 Lubricating Oil Management Criteria ................................................................... 4-5

4.1.6 Lubricating Oil Replacement Timing .................................................................... 4-6

4.1.6.1 After Starting the Initial Operation .............................................................. 4-6

4.1.6.2 During Normal Operation ........................................................................... 4-6

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Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

vii

4.2 Precautions for Operation ........................................................................... 4-7

4.2.1 Prevention of Liquid Flow-back ........................................................................... 4-7

4.2.2 Purging of Non-condensable Gases .................................................................... 4-7

4.3 When Stopping the Compressor for a Long Time .................................... 4-8

5 Maintenance and Inspection

5.1 Precautions for Maintenance and Inspection ............................................ 5-1

5.2 Maintenance and Inspection List................................................................ 5-3

5.2.1 Daily Management ............................................................................................... 5-3

5.2.2 Periodic Inspection .............................................................................................. 5-5

5.2.3 Guidelines for the Timing of Compressor Overhaul ............................................ 5-6

5.3 Compressor Disassembly Preparation ...................................................... 5-7

5.3.1 Disassembly Tools and Work Place .................................................................... 5-7

5.3.2 Replacement Parts .............................................................................................. 5-7

5.3.2 Refrigerant Gas Recovery ............................................................................... 5-10

5.3.4 Removing Parts Connected to the Unit ............................................................. 5-11

5.3.5 Compressor Removing and Lifting .................................................................... 5-12

5.3.6 Removing Oil from Inside the Compressor ........................................................ 5-12

5.4 Disassembly and Inspection ..................................................................... 5-13

5.4.1 Shaft Seal Block ................................................................................................ 5-15

5.4.1.1 Disassembly .............................................................................................. 5-15

5.4.1.2 Inspection .................................................................................................. 5-16

5.4.2 Unloader Indicator ............................................................................................. 5-17

5.4.2.1 Disassembly .............................................................................................. 5-18

5.4.2.2 Inspection .................................................................................................. 5-19

5.4.3 Unloader Cover .................................................................................................. 5-20

5.4.3.1 Disassembly .............................................................................................. 5-20

5.4.3.2 Inspection .................................................................................................. 5-20

5.4.4 Unloader Piston and Unloader Cylinder ............................................................ 5-21

5.4.4.1 Disassembly .............................................................................................. 5-21

5.4.4.2 Inspection .................................................................................................. 5-21

5.4.5 Speed increaser Gear Casing Cover ................................................................. 5-22

5.4.5.1 Disassembly .............................................................................................. 5-22

5.4.6 Speed increaser Gear Casing Block ................................................................. 5-23

5.4.6.1 Disassembly .............................................................................................. 5-23

5.4.6.2 Inspection .................................................................................................. 5-26

5.4.7 Separating High-stage and Low-stage .............................................................. 5-27

5.4.7.1 Disassembly .............................................................................................. 5-27

5.4.8 Gear Coupling .................................................................................................... 5-28

5.4.8.1 Disassembly .............................................................................................. 5-28

5.4.8.2 Inspection .................................................................................................. 5-28

5.4.9 Balance Piston Cover ........................................................................................ 5-29

5.4.10 Balance Piston ................................................................................................... 5-29

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Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

viii

5.4.10.1 Disassembly .............................................................................................. 5-29

5.4.10.2 Inspection .................................................................................................. 5-30

5.4.11 High-stage Suction Cover and Side Bearings ................................................... 5-31

5.4.11.1 Disassembly .............................................................................................. 5-31

5.4.11.2 Inspection .................................................................................................. 5-31

5.4.12 Low-stage Suction Cover and Side Bearings .................................................... 5-32

5.4.12.1 Disassembly .............................................................................................. 5-32

5.4.12.2 Inspection .................................................................................................. 5-33

5.4.13 Thrust Bearings Block ........................................................................................ 5-34

5.4.13.1 Disassembly of High-stage Thrust Bearing block ...................................... 5-34

5.4.13.2 Disassembly of Low-stage Thrust Bearing block ...................................... 5-35

5.4.13.3 Inspection (High-stage/Low-stage) ............................................................ 5-36

5.4.14 High-stage Rotors and Main Rotor Casing ........................................................ 5-37

5.4.14.1 Disassembly .............................................................................................. 5-37

5.4.14.2 Inspection .................................................................................................. 5-37

5.4.15 Low-stage Rotors and Main Rotor Casing ......................................................... 5-38

5.4.16 High-stage Bearing Head and Main Bearings ................................................... 5-39

5.4.16.1 Disassembly .............................................................................................. 5-39

5.4.16.2 Inspection .................................................................................................. 5-39

5.4.17 Low-stage Bearing Head and Main Bearings .................................................... 5-40

5.4.17.1 Disassembly .............................................................................................. 5-40

5.4.17.2 Inspection .................................................................................................. 5-40

5.4.18 Low-stage Unloader Slide Valve and Guide Block ............................................ 5-41

5.4.18.1 Disassembly .............................................................................................. 5-41

5.4.18.2 Inspection .................................................................................................. 5-41

5.5 Reassembly ................................................................................................ 5-42

5.5.1 Low-stage Unloader Slide Valve and Guide Block ............................................ 5-44

5.5.2 Bearing Head and Rotor Casing ........................................................................ 5-45

5.5.3 Bearing Head and Main Bearings ...................................................................... 5-46

5.5.4 Rotor Assembly ................................................................................................. 5-47

5.5.5 Suction Cover and Side Bearings ...................................................................... 5-48

5.5.6 Thrust Bearing Block (

....................................................................................... 5-50

5.5.6.1 End Clearance Measurement .................................................................... 5-52

5.5.6.2 End Clearance Adjustment Method ........................................................... 5-54

5.5.6.3 Tightening after End Clearance Adjustment ............................................. 5-54

5.5.7 Combining High-stage and Low-stage Blocks ................................................... 5-55

5.5.8 Balance Piston Cover ........................................................................................ 5-57

5.5.9 Speed Increaser Gear Block.............................................................................. 5-58

5.5.10 Installation of Speed Increaser Gear Casing to Low-stage Bearing Head ........ 5-61

5.5.11 Unloader Cylinder and Unloader Piston ............................................................ 5-63

5.5.12 Unloader Cover .................................................................................................. 5-65

5.5.13 Shaft Seal Block ................................................................................................ 5-66

5.5.14 Unloader Indicator ............................................................................................. 5-69

5.5.14.1 Potentiometer ............................................................................................ 5-70

5.5.14.2 Micro-switch ............................................................................................... 5-70

5.5.14.3 Assembly and Adjustment ......................................................................... 5-71

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Table of Contents

Compound 2-stage Screw Compressor 1612LSC Speed Increaser Type

6 Troubleshooting

01: Compressor does not start up ................................................................................ 6-1

02: Compressor stops immediately after startup .......................................................... 6-1

03: Unusually low pressure (decrease of suction pressure) ........................................ 6-2

04: Low oil pressure (low lubricating oil supply pressure) ............................................ 6-2

05: Intermediate pressure is unusually high ................................................................. 6-3

06: Unusually high pressure (abnormal discharge pressure) ...................................... 6-4

07: Discharge temperature is abnormally high ............................................................. 6-5

08: Leak from mechanical seal ..................................................................................... 6-6

09: Squeaking of mechanical seal................................................................................ 6-7

10: Capacity control position is indicated incorrectly.................................................... 6-7

11: Capacity control malfunction .................................................................................. 6-8

12: Compressor generates abnormal vibration and/or sound ...................................... 6-9

7 Related Documents

7.1 Development Views, Assembly Sectional Views ...................................... 7-1

■ Figure 7-1 Development View (Low-stage) ........................................................... 7-1

■ Figure 7-2 Development View of the Parts Assembly (High-stage) ...................... 7-2

■ Figure 7-3 Assembly Sectional View (Vertical) ...................................................... 7-3

■ Figure 7-4 Assembly Sectional View (Horizont al) ................................................. 7-4

7.2 Parts Configuration Table ........................................................................... 7-5

7.3 Tightening Torques for Bolts and Nuts ..................................................... 7-9

7.4 O-rings for Use ........................................................................................... 7-11

7.4.1 List of O-rings for Use ........................................................................................ 7-11

7.4.2 List of O-ring Materials for Screw Compressor .................................................. 7-11

7.5 Tools for Disassembly ............................................................................... 7-12

Contact Information

Sales Offices in Japan ........................................................................................... Contact-1

Manufacturing Bases in Japan ............................................................................... Contact-1

Global Network ....................................................................................................... Contact-2

NORTH AMERICA ........................................................................................................ Contact-2

EUROPE and AFRICA .................................................................................................. Contact-2

ASIA PACIFIC ............................................................................................................... Contact-3

LATIN AMERICA ........................................................................................................... Contact-5

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1. Safety

Compound 2-stage Screw Compressor 1.1 Strict Requirements and Prohibitions 1612LSC Speed Increaser Type

1-1

1. Safety

1.1 Strict Requirements and Prohibitions

1.1.1 Strict Requirements (Do’s)

1.1.1.1 Do’s on Operation

 Make sure to install safety and protective devices on the package unit.  Regularly inspect the safety and protective devices if they function properly.  If the safety or protective devices do not work properly or if this product operates abnormally,

immediately stop the operation and report to the supervisor. Obtain his/her approval and direction before restarting this product.

 If this product stops for unknown reasons, immediately inform your supervisor of it. Obtain

his/her approval before restarting the compressor.

 Some types of refrigerants emit bad smell or toxic gases when they leak. Make sure to

ventilate the air during operation.

 For the properties of refrigerant and lubricating oil (corrosiveness, decomposability or toxicity),

be sure to obtain the Safety Data Sheet (SDS) and follow the relevant information.

 When stopping the operation of this product, close the suction and discharge side shut-off

valves and turn "OFF" the motor (main power), heater power, and control power.

1.1.1.2 Do’s on Maintenance

 Prepare work procedures based on a work schedule. Be sure to perform danger forecasting

before starting the work.

 Before performing the work together with at least one other person, thoroughly confirm each

other's work details and procedures to acknowledge the other worker's movement.

 When troubleshooting during operation or before performing setup, cleaning, maintenance, or

inspection of this product, always turn OFF the main power to the motor and control power and other devices. Also, lock and tag out them to prevent the power from being supplied erroneously during operation.

 When troubleshooting during operation or before performing setup, cleaning, maintenance, or

inspection of this product, confirm that the pressure inside this product a nd the package unit is at atmospheric pressure.

 Some refrigerants in use generate bad smell or toxic gases, or may cause deficiency of

oxygen. Before starting work, measure oxygen concentration in the work area as necessary. Ventilate the area well. Be sure to keep the are a well ventilated until the work is finished.

 For the properties of refrigerant and lubricating oil (corrosiveness, d ecomposability or toxicity),

be sure to obtain the Safety Data Sheet (SDS) and follow the relevant information.

 After using tools always restore to de sig nated place and neve r leave tools in the p a ckage unit.

1.1.1.3 Do’s on Lockout/Tagout after Shutting Off the Power

 Attach lockout/tagout mechanism to the main breakers of motor main power and control power.

Lockout/tagout after power off is a very effective means to secure safety. It can prevent the power source from being turned on by accident by two or more workers which may cause injury to other worker(s).

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1. Safety

Compound 2-stage Screw Compressor 1.1 Strict Requirements and Prohibitions 1612LSC Speed Increaser Type

1-2

 If there are any possibilities of danger during works (especially during cleaning, maintenance

and inspection, and troubleshooting), turn "OFF" the motor main power and control power , an d perform lockout/tagout.

 In the following situations, workers may neglect to perform power source shutoff or

lockout/tagout. Clearly notify the workers of the necessity of lockout/tagout.

 It is assumed that workers do not perform lockout/tagout before starting work b ecause it i s

troublesome, and only turn "OFF" the main motor and control power.

 It is assumed that workers only turn off the main motor and control power and do not

lockout/tagout the main motor and control power, because they judge that there is no danger.

1.1.1.4 Do’s about Personal Protective Gear

 Prepare and use protective gear complying with the safety standards of the regulations.  Check the function of each protective gear before using.  Wear designated clothes such as work outfits, with their cuffs tightly closed.  Do not wear any neckties or jewelry as there is a risk of being entangled by a movable part or

rotating part. Put on a helmet as your hair may get entangled.

 Do not have anything in your pocket to prevent objects from falling into the package unit.

1.1.1.5 Do’s about Handling of Hazardous and Toxic Substances

 Obtain the Safety Data Sheet (SDS) from manufactu rers of hazardous and toxic substances.

Check the SDS and follow the handling instructions recommended by the manufacturers to handle and store those substances.

1.1.1.6 Do’s about Handling Emergency Situations

 Formulate an emergency action plan complying with the regulations, and post it on a safe

place.

1.1.1.7 Do’s about Waste Oil, Fluid, and Materials

 Disposing of refrigerant and oil used for this product are subject to a number of regulations for

the environmental protection purposes. Follow the local, state, federal acts and regulations and your company's rules when disposing of such waste oil, fluid and materials.

1.1.1.8 Other Do’s

 Clean the floor around the entire refrigerating/cold storage/gas compression package unit.

Provide a safety passage.

 Walk only on the areas set up as a work floor. Also, do not leave tools and cleaning solutions

in that area.

 If water or oil is spilled on this product or the floor, immediately wipe it off to prevent workers

from slipping and getting injured.

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Compound 2-stage Screw Compressor 1.2 Warnings 1612LSC Speed Increaser Type

1-3

1.1.2 Prohibitions (Don’ts)

 Do not remove or relocate any safety device, including electrical interfaces.  Do not disable any safety device by short-circuiting or bypassing without any permission.  Do not leave this product unsafe and unattended, by removing a safety cover or some other

measures.

 Do not touch, clean or lubricate any part of this product which is moving.  Do not touch relays or electric systems such as terminal block with bare hands when turning

on the power.

1.2 Warnings

The warning messages described in this manual warn dangerous situations that may arise during work by using the following four categories.

Neglecting such warnings may cause accidents, resulting in personal inju ry or even death. Also, this product or its auxiliary equipment may be heavily damaged. Therefore, be sure to always

observe the instructions of the warnings.

T able 1-1 Warning Symbols and their Meanings

Symbol Meaning

Indicates a hazardous situation which, if not avoided, could very likely cause serious injury or death. Indicates a potentially hazardous situation which, if not avoided, may cause serious injury or death. Indicates a potentially hazardous situation which, if not avoided, may cause minor or moderate injury. Indicates a potentially hazardous situation which, if not avoided, may result in property damage.

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1. Safety

Compound 2-stage Screw Compressor 1.3 Residual Risks 1612LSC Speed Increaser Type

1-4

1.3 Residual Risks

The following information assumes that this product is operated or inspected/maintained while being used in general refrigerating/cold storage/gas compression package units.

Note that all hazardous sources cannot be predicted for the applications mentioned. Devise appropriate countermeasures for hazardous sources in your systems.

T able 1-2 Hazardous Sources

Hazardous sources Predicted hazard

Countermeasures in

operation

Countermeasures in

cleaning, inspection,

and parts exchange

Motor and compressor coupling Refer to Figure 1-1

 Caught in due to contact  Install coupling cover

and prohibit opening.

 Keep away.

 Turn off motor main

power and control power, and conduct lockout/tagout.

Motor terminals

 Electric shock caused by

contact with live wires or electrical leakage

 Keep away.  Do not open terminal

boxes.

 Do not touch terminal

boxes.

 Turn off motor main

power and control power, and conduct lockout/tagout.

Compressor low-stage side suction casing Refer to Figure 1-1

 Frostbite due to contact  Contact with or inhalation

of hazardous substances generated by leakage of refrigerant or the like

 Keep away and do not

touch.

 Wear protective gear.  Detect gas leakage.

 Wear protective gear.  Work under room

temperature.

Compressor intermediate piping (low-stage discharge port to high stage suction port) Refer to Figure 1-1

 Burn injury due to contact  Contact with or inhalation

of hazardous substances generated by leakage or spout of refrigerant or the like

 Keep away and do not

touch

 Wear protective gear  Gas leakage detection

 Wear protective gear  Work in temperatures

below 40 °C

Compressor high-stage side discharge casing and discharge piping Refer to Figure 1-1

 Burn injury due to contact  Contact with or inhalation

of hazardous substances generated by leakage or spout of refrigerant or the like

 Keep away and do not

touch.

 Wear protective gear.  Detect gas leakage.

 Wear protective gear.  Work at a temperature of

not higher than 40°C.

Check valves/service valves and joints on each section of the package unit

 Contact with or inhalation

of hazardous substances generated by mishandling or leakage

 Frostbite or burn due to

contact

 Sufficient ventilation  Indicate valve

open/close state.

 Keep away and do not

touch.

 Wear protective gear.

 Sufficient ventilation  Wear protective gear.  Tagout for controlled

valve

Solenoid valves/motor operated valves on each section of the package unit

 Electric shock caused by

contact with live wires or electrical leakage

 Pinched due to contact

with driving part

 Install protective cover

on terminals, and prohibit opening.

 Keep away and do not

touch.

 Wear protective gear.

 Turn off each breaker and

the control power, and conduct lockout/tagout.

 Wear protective gear.

Electric components in each section of the package unit (oil heater, protective switch, etc.)

 Electric shock caused by

contact with live wires or electrical leakage

 Pinched due to contact

with driving part

 Install protective cover

on terminals, and prohibit opening.

 Keep away and do not

touch.

 Wear protective gear.

 Turn off each breaker and

the control power, and conduct lockout/tagout.

 Wear protective gear.

Package unit oil drains

 Contact with hazardous

substances generated by leakage or spout

 Burn caused by contact

with high-temperature fluid

 Sufficient ventilation  Keep away and do not

touch.

 Wear protective gear.

 Sufficient ventilation  Wear protective gear.  Work at a temperature of

not higher than 40°C.

Noises

 Damage caused b y noise  Wear protective gear.

—

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1-5

Figure 1-1 Locations of Hazardous Sources (compressor)

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1. Safety

Compound 2-stage Screw Compressor 1.4 Safety Devices 1612LSC Speed Increaser Type

1-6

1.4 Safety Devices

For safe use and protection of this product, make sure to attach safety devices to this product in accordance with the regulations and the following instructions.

Safety devices cannot be kept in normal condition unless inspected and maintained at re gular intervals. Their maintenance and inspection need to be performed as an important part of the maintenance/inspection work project. Provide users of this product with necessary information on the safety devices, for example, types of the safety devices, installation position, function, and inspection method of safety related devices.

 Check the safety devices after turning on the power and before operation of this

product. If they do not operate normally, immediately take repair or replace safeties before starting this product.

1.4.1 Emergency Stop Button

 Overview/Function/Purpose

The emergency stop buttons are used to stop the compressor operation immediately if an emergency occurs in this product.

 Installation Positions

On the control board and in the operation control room

 Stop/Restoration Methods

The operating procedures for the emergency stop button, i.e., how to stop the operation and restore the normal operating condition, must be clearly defined and the information provided to the user of this product.

 Inspection Method/Cycle

The emergency stop buttons must be tested before commissioning and must also be periodically re-tested after that. The inspection procedures and the inspection interval for the emergency stop button must be clearly defined and the information provided to the user of this product.

1.4.2 Breakers of Motor Main Power and Control Power (with Lockout/Tagout Mechanism)

 Overview/Function/Purpose

Turn off the main motor and control power, and if there is any possibility of danger during work (especially during cleaning, maintenance, inspection, or troubleshooting), lockout/tagout devices must be used on the breakers of the main motor and control powers to prevent injuries to workers in case the power is turned on accidentally during work.

 Methods of Performing and Releasing Lockout/Tagout

Make sure to clearly notify methods of performing and releasing lockout/tagout referring to the regulations created by Occupational Safety & Health Administration (OSHA) or local governing body.

 Inspection Method/Cycle

The inspection procedures and the inspection interval for the lockout/tagout devices must be clearly defined and the information provided to the user of this product.

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Compound 2-stage Screw Compressor 1.4 Safety Devices 1612LSC Speed Increaser Type

1-7

1.4.3 Compressor Protective Devices

 Be sure to adjust the set values and check operation of the protective devices at

the commissioning.

 Overview/Function/Purpose

These protective devices are used to protect this product.

 Protecting from discharge temperature rise (DT)

This device stops the compressor operation when the discharge temperature of the compressor exceeds the set value.

Install a temperature sensing port to the discharge pipe.

 Protecting from oil temperature rise (OT)

This device stops the compressor operation when the oil temperature of the compressor exceeds the set value.

Install a temperature sensing port to the package unit's oil supply pi pe (after the oil cooler).

 Protecting from high pressure (HP)

This device stops the compressor operation when the discharge pressure abnormally rises due to mishandling of the compressor or stoppage of cooling water supply to the condenser.

This device prevents explosion of the equipment and component s. Install a pressure sensing port to the discharge pipe.

 Protecting from intermediate pressure (IP)

This device controls the compressor appropriately when the intermediate pressure exceeds the set value.

In some cases, this device stops the compressor operation.

Install a pressure output port to the package unit's intermediate gas pipe (or compressor's intermediate gas pressure output port).

 Protecting from suction pressure drop (LP)

This device stops the compressor operation when the suction pressure becomes below the set value.

Install a pressure sensing port to the suction pipe.

 Protecting from oil pressure (OP)

This device stops the compressor operation when lub ricating oil sup ply is not sufficient, the oil filter is clogged, the refrigerant is mixed into the lubricating oil, and oil supply pressure difference (from discharge pressure) becomes below the set value.

This device is to protect the compressor from wear and burnout. Install a pressure sensing port to the package unit' s oil sup ply pipe (af ter the oil p ump) and the

discharge pipe.

 Protecting from motor overcurrent (OCR)

This device controls the compressor appropriately when the current exceeds the set value. In some cases, this device stops the compressor operation.

This device is normally installed in the compressor operation controller.

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Compound 2-stage Screw Compressor 1.4 Safety Devices 1612LSC Speed Increaser Type

1-8

 Connection Positions and Settings

Specify the connection position and setting for each compressor protective device, and make sure to provide users of this product with them.

Make sure that the set values do not exceed the operating limits shown in Chapter 2, section 2.3.2 and Table 2-2 of this manual.

 Inspection Method/Cycle

Compressor protective devices require operation tests and confirmation of the settings calibration before test run as well as at regular intervals.

Specify the inspection methods/intervals of the compressor protection devices, and make sure to provide users of this product with such information.

 In the operation test, check that alarms and protective devices operate norm ally

by using devices such as pressure tester. Do not operate the compressor with all the valves closed, or in any other dangerous conditions.

 If the protection from oil pressure (OP), high pressure (HP) activates, do not

restart operation until the cause of activation is removed.

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2 Compressor Specifications and Structure

Compound 2-stage Screw Compressor 2.1 Overview of the MYCOM 1612LSC Speed Increaser Type

1612LSC Speed Increaser Type

2-1

2 Compressor Specifications and Structure

2.1 Overview of the

Compound 2-stage

Screw Compressor 1612LSC Speed Increaser Type

The 1612LSC is a compound screw compressor integrating two stages of compressor into a single body. The 1612LSC has been developed based on the LSC model of the 1612C Series compressors —our most popular and long-selling products boasting the delivery of over 1000 units worldwide since they were first put on the market— by adding the speed increaser gear system to provide it with optimum performance for applications to ultra-cold and rapid freezing storage systems in bonito and tuna fisheries.

Generally, screw compressors use oil injection to keep discharge temperature low during operation without loss of volumetric efficiency even at high compression ratios, with singles-stage usage possible even at evaporative temperatures near −40 °C.

However, for low-temperature regular usage, to improve KW/RT (the ratio of power consumption versus cooling ability), a 2-stage compression method is used. To use standard-type screw compressors in a 2-stage compression method, at least two screw compressors must be combined so that there is a high-stage and a low-stage, which requires multiple sets of machinery, power, and utilities, etc. to be installed.

This 2-stage screw compressor combines these two units into one compound machine.

2.2 Model Designation of the Compressor

This manual describes the 1612LSC-*B*-52, -62, -53, -63, and -54 speed increaser type models. The meaning of the type designation stamped on the nameplate of the compressor MODEL column is as follows.

＊1612LSC-＊B＊-52（62, 53, 63, 54）

2, 3 or 4

：Speed increaser gear ratio specification

( refer to the specifications table on the next page.)

5：Power frequency 50Hz （6：60Hz）

Vi of the high-stage discharge port specification (volume ratio),

as standard L port or M port

Means the machine (low-stage) booster

Vi of the low-stage discharge port specification (volume ratio),

as standard L port or M port Means two-stage machine single unit

Shows the specifications of the high-stage rotor length,

only S for accelerator

speed increaser type

Shows the specifications of the low-stage rotor length, only L for speed increaser type High-stage rotor

diameter of 125

Low-stage rotor diameter of 160

Means the working fluid

(Example: N = ammonia, F = Freon, P = Propane , HE = helium)

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Compound 2-stage Screw Compressor 2.3 Compressor Specifications 1612LSC Speed Increaser Type

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2.3 Compressor Specifications

2.3.1 Standard Specifications

Table 2-1 1612LSC Speed Increaser Type Screw Compressor Specifications

Item

1612LSC Speed Increaser type

52 62 53 63 54

Product mass kg 560

Applied frequency Hz 50 60 50 60 50

Motor Poles - 4P 4P 2P 2P 2P

Speed increaser gear ratio - 1.809 1.809 1.220 1.220 1.472

Male rotor rotational speed min

-1

2610 3150 3610 4350 4350

Female rotor rotational speed min

-1

1740 2100 2407 2900 2900

Low-stage swept volume m3/h 551 665 762 918 918

High-stage swept volume m3/h 174 210 241 290 290

Applied refrigerant - Ammonia, Hydrofluorocarbon, other

Design pressure MPa 2.6

Capacity control range (Actual load) % 10 to 100

Rotation direction - Crockwise viewed from motor

Connection pipe size

Suction flange low-stage - MYCOM 125A (5″)

Discharge flange low-stage

- MYCOM 80A (3″)

Suction flange high-stage - MYCOM 80A (3″)

Discharge flange high-stage

MYCOM 65A (2½″)

Journal lubricating oil supply (low-stage)

- Rc1/2

Journal lubricating oil supply (high-stage)

- Rc3/8

Oil injection lubricating oil supply

- Rc3/8

Mechanical seal and speed increaser gear lubricating oil supply

- Rc1/4

Capacity control - Load: Rc1/4, Unload: Rc3/8

 In this manual unless otherwise noted, pressure units MPa represents the gauge pressure.  For usage temperature ranges and pressure ranges, refer to Section2.3.2 “Operation Limits”.

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Compound 2-stage Screw Compressor 2.3 Compressor Specifications 1612LSC Speed Increaser Type

2-3

2.3.2 Operation Limits

Table 2-2 Operation Limits of 1612LSC Speed Increaser type

Items Operation Limits

Maximum discharge pressure MPa 1.96

Minimum suction pressure MPa −0.080

Maximum intermediate pressure MPa 0.588

Minimum intermediate pressure - > Suction pressure

Oil supply pressure

･ Maximum journal lubrication pressure MPa Discharge pressure + 0.39

･ Minimum journal lubrication pressure

MPa

Discharge pressure +0.049 and Suction pressure +0.49

･ Minimum oil injection pressure MPa Suction pressure +0.49

Maximum Suction temperature °C 85

Minimum suction temperature °C −60

Maximum low-stage discharge temperature °C 90

Maximum high-stage discharge temperature °C 100

Maximum oil supply temperature °C 60

Minimum oil supply temperature °C 30

Maximum M (mail) rotor rotation speed min-1 4500

Minimum M (male) rotor rotation speed min-1 1450

Note : Unless otherwise noted, the pressure unit MPa represents the gauge pressure in this manual.

 If operation at a indicated load of less than 30 % of capacity control is continued

for a long time except when starting up the machine, abnormal noises or vibration may occur, so avoid doing so.

 Repeating startup or shutdown operations in a short period of time is detrimental

for the starter and the motor as well as for the compressor itself. Refer to the documentation of each device for the starting and stopping limitations of the starter and the motor. After stopping the compressor, wait 15 minutes or more before performing the next startup procedure.

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Compound 2-stage Screw Compressor 2.3 Compressor Specifications 1612LSC Speed Increaser Type

2-4

2.3.3 Outer Dimensions

Figure 2-1 1612LSC Speed Increaser Type Outer Dimensions

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2 Compressor Specifications and Structure

Compound 2-stage Screw Compressor 2.4 Structure of Compressor 1612LSC Speed Increaser Type

2-5

2.4 Structure of Compressor

 For the names and locations of the compressor components, refer to Section 7.1 “Development

Views, Assembly Sectional Views” and Section 7.2 “Parts Configuration Table” in this manual.

Figure 2-2 1612LSC Speed Increaser Type Sectional View

The 162LSC screw compressor consists of the following four main blocks: the shaft seal block which prevents leakage of the refrigerant gas and lubricating oil from the compressor’s axis; the speed increaser gear casing assembly which houses the drive and driven gears for increasing the rotating speed of the electric motor’s output shaft; the low-stage compressor block which pressurizes (pre-compresses) the gaseous working fluid coming from the freezing storage system; and the high-stage compressor block which further compresses the working fluid gas pressurized by the low-stage compressor before discharging it into the freezing storage system.

Like with the 1612**C Series direct drive type screw compressors, the 1612LSC speed increaser type screw compressors has the capacity control (unloading) mechanism which works for reducing the machine load at the time of the start of operation and keeping constant the load which would otherwise vary during operation of the freezing storage system.

Inside each of the low-stage and high-stage compressor casings, there is a pair of screw rotors meshing each other and supported by bearings at both ends. One of each pair is the male rotor having four convex-shaped screw lobes and the other is the female rotor having six concave-shaped screw lobes. In combination, they perform the work of compressing the refrigerant gas through the process described in the next section.

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Compound 2-stage Screw Compressor 2.5 Mechanisms 1612LSC Speed Increaser Type

2-6

2.5 Mechanisms

2.5.1 Basics of the Screw Compressor

The screw compressor is a positive displacement rotary comp ressor. As shown in Figure 2-3 Compressor Mechanism, the refrigerant (gas) is continuously compressed by

changing the volume between the casing and the male and female meshed screw rotors, which have different profiles.

The rotor with 4 protruding lobe sections is called the M rotor (male rotor), and the rotor with 6 lobe depressions is called the F rotor (female rotor). Throughout this manual they are referred to as the M rotor and F rotor.

The compressor M rotor shaft is driven by the two-pole or four-pol e motor via the spe ed i ncreaser ge ar.

Figure 2-3 Compressor Mechanism

2.5.2 Suction Process

As shown in Figure 2-4 Suction Process, the rotors’ different profiles mesh together. Also the volume enclosed between the M and F rotor lobes and compressor casing increa ses from the suction side as the rotors turn.

As rotations continue, at a certain point the volume reaches it s maximum, the rotors start to tra p the gas between the lobes and compressor casing thereby isolating the gas from the suction port.

Figure 2-4 Suction Process

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Compound 2-stage Screw Compressor 2.5 Mechanisms 1612LSC Speed Increaser Type

2-7

2.5.3 Compression Process

As the rotors further rotate, the sealing line between them moves toward the discharge side and the volume between the rotor lobes decreases and compresses the trapped gas.

Figure 2-5 Compression Process Figure 2-6 Discharge Process

2.5.4 Discharge Process

Through the compression process, the volume between rotor lobes decreases to a predetermined value at the discharge port.

Following rotor rotation, the compressed refrigerant gas is pushed out of the discharge port.

2.5.5 About Volume Ratio (Vi)

Volume ratios (Vi) of C-series screw compressors are indicated in performance tables or catalogs by using port symbols L and M.

The volume ratio represented by each symbol is as follows:

L=2.63, M=3.65.

Which volume ratio (L or M) should be used is decided according to operating conditions. If the compressor is used with a volume ratio that does not match operating conditions, operation will go inefficiently wasting the power.

The relationship between volume ratios and generally used compression ratios is as follows:

(Vi)

= πi = Pd/Ps κ= Cp/Cv of refrigerant gas

Vi = designed volume ratio πi = designed compression ratio

The constant of the refrigerant gas also a factor, and the Vi value for the compression ratio will change according to the refrigerant gas used.

Figure 2-7 Volume Ratio Explanation

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2 Compressor Specifications and Structure

Compound 2-stage Screw Compressor 2.5 Mechanisms 1612LSC Speed Increaser Type

2-8

(A) When Vi matches operation conditions

The required compression ratio and Vi are both low The required compression ratio and Vi are both high

(B) When Vi does not match operation conditions

Vi is too low compared to

the required compression ratio

Vi is too high compared to

the required compression ratio

Figure 2-8 Relationship between volume ratio (Vi) and operation conditions

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2 Compressor Specifications and Structure

Compound 2-stage Screw Compressor 2.5 Mechanisms 1612LSC Speed Increaser Type

2-9

2.5.6 Capacity Control Mechanism

The capacity control structure involves the moving of a slide valve, bypassing suction gas just before compression on the suction side, which shortens the portion of the rotor used for compression. The slide valve is at the bottom of the casing where the rotors mesh together, and is constructed to move parallel to the rotor’s axis. This movement is changed by a cam mechanism into rotation movement, and as the position (capacity control ratio) is indicated externally, the electrical resistance value changes to provide feedback to the automatic control circuit.

Figure 2-9 Capacity Control Mechanism

The 1612LSC speed increaser type has capacity control on the lo w-stage block only.

2.5.7 Bearings and Balance Piston

For the load created on the rotor perpendicular to the axle, a white metal-lined sleeve-type bearing is used. The bearing uses surface fitted ball bearings with angular contact for loads along the axis direction.

In particular, axial load for the M rotor, which has one type of helical gear, is comparatively larger than that of the F rotor because of the thrust load from discharge pressure. This load for the M rotor is reduced by the use of a thrust bearing, along with a balance piston providing opposing hydraulic pressure.

2.5.8 Shaft Seal

To prevent refrigerant gas and oil leakage, a reliable mechanical seal assembly is used for the shaft seal of the speed increaser gear spindle.

Mechanical seal assembly is mainly composed of "rotating ring" installed on the rotor shaft and "stationary ring" installed in the seal cover. Rotating ring rotates with the shaft, and slides each other with the stationary ring while maintaining a micron class gap. The sliding each other place is called as the sliding surface.

As an example, for the BBSE (Balanced Bellows Single Seal)-type, which is a standard seal currently in use, the fixed ring (mating ring) is cast iron, and the rotating ring is carbon, with an O-ring for the packing.

Figure 2-10 Slide Valve in the

Rotor Casing

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Compound 2-stage Screw Compressor 2.6 Gas and Oil Flow 1612LSC Speed Increaser Type

2-10

2.6 Gas and Oil Flow

The screw compressor’s compression process is described earlier in this manual.

Gas for the compound speed increaser type 1612LSC compressor passes from the evaporator and through the suction strainer and check valve, and is sucked into the center part of the compressor ①, and it is compressed at the low-stage ② .Then the compressed gas is discharged at ③. ③ and ④ are connected by piping through which gas used for super cooling is mixed in from the liquid cooler.

Lubricating oil injected at the low-stage is, while kept mixed with gas, suctioned from ④ into the high-stage. After being compressed at ⑤, the gas mixed with lubricating oil is discharged from ⑥ to the oil separator, and then sent to the condenser.

The oil is cooled even without intermediate gas cooling, so the high-stage discharge temperature can be maintained at below 90 °C.

 Oil Supply Route

Lubricating oil is split into 4 flows as shown in Figure 2-12, and after providing lubrication, it is mixed with discharge gas and leaves the compressor. In standard configurations, oil injection is not performed at the high-stage.

Figure 2-12

1612LSC Speed Increas er Type Oil Supply Route

Figure 2-11 Gas Flow

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3 Installation

Compound 2stage Screw Compressor 3.1 General Precautions for Installation 1612LSC Speed Increaser Type

3-1

3 Installation

3.1 General Precautions for Installation

 This chapter is based on the assumption that the compressor is installed to a standard

refrigeration/cold storage package unit. If the package unit is not a standard refrigeration/cold storage package unit, prepare an installation procedure manual referring to this chapter and considering safety precautions, before installing the compressor. If there are any questions, please contact our local sales offices or service centers.

 In some cases, it may be required that installation is performed by qualified personnel.

Make sure that the work is performed by qualified personnel in compliance with local laws and ordinances.

 Read this chapter and related documents, and fully understand their contents before

performing installation.

 Electrical work must be performed only by electrical engineers .

3.2 Installation Works

3.2.1 Unpacking

Check that there are no abnormalities such as damage on the compressor.

 If there are abnormalities or deficient parts on the compressor, please contact our local sales

offices or service centers.

 Unnecessary packaging materials should be discarded according to the laws and ordinances, or

your company’s rules.

3.2.2 Storage

If you need to store the compressor before installation, perform the followings:

 Store it indoors.

 Seal nitrogen gas in the compressor. (Pressure: approximately 0.15 MPa)

3.2.3 Transportation

 Dropping of the lifted compressor may cause death or serious injury to the

worker. Do not allow anyone to be under the lifted compressor.

1. To lift the compressor, use lifting equipment with sufficient load capacity for the mass of the

compressor and appropriate lifting slings having proof load of more than the mass of compressor.

2. Secure sufficient space for safe lifting.

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3 Installation

Compound 2stage Screw Compressor 3.2 Installation Works 1612LSC Speed Increaser Type

3-2

3. Check the wire ropes before use. Thoroughly check the wire ropes for problems such as kinks,

knots, and broken strands. Do not start lifting unless the wire ropes have been verified and have no problems. If you cannot make a correct evaluation or judgment, entrust an expert to inspect.

4. To lift the compressor, attach the wire ropes to the attached eyebolts using appropriate shackles

and hooks. The eyebolts are only used for lifting the compressor. Do not use the eyebolts to lift the compressor with any attached apparatus.

 The compressor eyebolts must not be used to lift the p ackage unit. To lift the package

unit, use the lifting chains on the compressor unit base periphery or other lifting devices provided on the compressor unit base.

5. Check the transportation route for any obstacles in consideration of the compressor size.

6. Before lifting, check that the hook is located above the gravity center of the compressor.

7. Instruct all workers to move from near the work site before lifting.

8. Before lifting the compressor, alert all workers on the site of possible dangers of the lifting process

by signal (such as calling at the beginning of the work or making a signal by hand). Do not lift the compressor unless the signals are completely understood by all personnel working together.

9. Slowly windup the wire ropes until shortly before the compressor leaves the ground.

10. Then, wind up the wire ropes a little further until the compressor is slightly away from the ground

and check that the compressor is balanced. If the compressor is inclined, return the compressor to the ground and correct the inclination by adjusting the wire ropes. Then, restart the lifting operation.

11. Make sure to wind up the compressor slowly. Lifting it too quickly may damage the lifting equipment

including the wire ropes or part of the compressor.

12. When lifting the compressor, check the state of the wire ropes and lifting equipment. Check that the

compressor is not inclined.

13. When moving the lifted compressor, always use guiding ropes.

14. When moving the compressor, turn away workers from the movement direction and check safety.

15. Do not lift the compressor above any safety aisles unless absolutely necessary.

16. Do not put the compressor in a safety aisle. Always keep the safety aisle free of obstacles.

17. Remove any obstacles before putting down the compressor on the ground. The compressor should

not be inclined or unstable.

18. Before putting down the compressor on the ground, announce to the workers around the working

area.

19. When lowering the compressor onto two or more blocks, align the tops of blocks so that the

compressor becomes stable horizontally on them.

20. Lower the compressor slowly so that it does not get damaged due to impact.

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 Outer Dimensions, Mass and Lifting Position

1612LSC speed increaser type common

Mass (kg) 560

Length (mm) 1372

Figure 3-1 Outer Dimensions, Mass and Lifting Position of Compressor

Lifted View

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3.2.4 Preparation for Installation

 Installation Space

Prepare sufficient working space for easy operation, cleaning, maintenance, and inspection.

 Illumination

Prepare lighting for easy operation, cleaning, maintenance, and inspection.

 Ventilation

If natural ventilation is insufficient, install ventilation fans according to the regulations.

 Piping

Table 3-1 Connected Piping List (Compressor)

Item Dimensions Remarks

Suction gas inlet MYCOM 125A (5″) See figure 3-2.

Low-stage gas outlet MYCOM 80A (3″) See figure 3-2.

High-stage gas inlet MYCOM 80A (3″) See figure 3-2. High-stage discharge gas outlet MYCOM 65A (2½″) See figure 3-2.

Low-stage bearing (journal) oil inlet Rc1/2

Low-stage capacity control oil inlet (increase side) Rc1/4

Low-stage capacity control oil inlet (decrease side) Rc3/8

Oil injection inlet Rc3/8

Mechanical seal and speed increaser gear oil inlet Rc1/4

High-stage bearing (journal) oil inlet Rc3/8

D t g C N-h y 65A □144 4.5 101 144 4-M16 × P2 24 80A □154 4.5 119 158 4-M20 × P2.5 25

125A 270 5 174 230 8-M20 × P2.5 27

Figure 3-2 MYCOM Flange Dimensions

* In external dimensions figures 2-1 in “2.2.2 Outer

Dimensions” in chapter 2 of this manual, these MYCOM flange dimensions are noted as MYK**A.

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3.2.5 Installation

3.2.5.1 Installation

Check that the surface of the package unit for compressor installation is even and horizontal. If it is not flat and horizontal, tightening the bolts may lead to compressor deformation, and operation may be affected.

3.2.5.2 Shaft Alignment between Compressor and Driving Machine

 Turn off the main power and control power of the driving machine before shaft

alignment work between the compressor and the driving machine. Be careful so that the power of instruments does not turn on during shaft alignment work. If the power turns on during shaft alignment work, the driving machine starts moving and there is a risk of being entangled with the rotating shaft.

 At the time of turning ON/OFF each electric power breaker, make sure to prevent

electric shock.

 For shaft alignment work between the compressor and driving machine, use designated

tools in normal condition. If a worn or damaged tool or a tool unsuitable for the work is used, there is a risk of being injured.

In the case shaft alignment between the compressor and the driving machine, be sure that the deviations within the range shown in the Table 3–2. However, if alignment tolerance of the driving machine side is more stringent than Table 3-2, please adjust to the request within the allowable value of the driving machine side.

T able 3– 2 Tolerance of Misalignment Tolerance

Offset 6/100 mm

Angularity 3/100 mm (reference: Φ100 mm)

The Figure 3–3 and 3–4 show how to measure offset and angularity when performing the centering of the shafts of the driving machine and this product using a dedicated hub, a dial gauge and a magnet stand.

Figure 3-3 Measurement of Offset Figure 3-4 Measurement of Angularity

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3-6

3.2.5.3 Piping Connection

 Refrigerant Piping

When connecting the refrigerant piping to the compressor, follow the instructions below.

 The compressor is one of the few devices with moving components in the package unit.

The moving components are adversely affected by foreign substances within the system (scale, dust, spatter, etc.). Therefore when connecting the piping, make sure that no such foreign substances enter the piping.

 In some compressors, in particular those shipped overseas, nitrogen gas is enclosed to

prevent rust. Release the pressure before starting piping work.

 Do not allow moisture to enter the piping because it can cause trouble after starting operation.

Assemble piping when it is dry.

 Cover flanges are attached to the low-stage gas outlet and the high-stage gas inlet of the

compressor, but after installation attach piping (intermediate piping) to both connection ports.

 Inappropriate piping may cause operating problems such as oil not returning to the

compressor or liquid flowing back to the compressor.

 When connecting piping to the compressor, as a general rule, use piping that is the same size

as the compressor connection port. If the size of the piping is smaller than the compressor connection port, the flow of lubricating oil or refrigerant will be obstructed leading to problems.

 Do not block flange or fittings with the mass of the piping connected to the compressor.

Prepare the appropriate support for piping.

3.2.5.4 Equipment and Devices for Protection of the Compressor

 Oil Filter

According to the requirements of the use of the package unit or the standard to apply, install an oil filter of appropriate filtration precision in the lubrication system of the compressor.

In the case of general applications such as closed-cycle refrigeration systems, we recommend to use an oil filter with beta ratio in the range of β

≥ 150 that conforms to requirements of NAS 1638

class 8 or ISO 4406 17/15/13. When the package unit requires API 619 4th/5th edition conformity, use an oil filter with beta ratio in

the range of β

≥200.

The oil filter may be clogged just after commissioning. We recommend installing two oil filters in parallel. This will enable replacement of either filter during operation.

 Oil Heater for Oil Separator

To preserve the temperature of the lubricating oil before starting the compressor, install an oil heater on the oil separator. Make sure to install a protection function (thermostat, etc.) to prevent overheating.

 Suction Strainer

When compatible (inter-soluble) oil is used, the mesh size of suction strainer should be not less than 200 meshes. When incompatible (non- inter-soluble) oil is used, it should be not less than 100 meshes.

For details about compatible and incompatible oils, refer to Section 4.1 "Lubricating Oil (Refrigerant Oil)" in this manual Chapter 4.

During commissioning, small particles and scale may come from the system. We recommend to install a finer filter temporarily.

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 Compressor Protective Devices (Safety Devices)

To protect the compressor, install the protective devices as indicated in Section 1.4.3 "Compressor Protective Devices" in this manual Chapter 1.

3.2.6 Airtightness Test

Perform an airtightness test on the package unit before starting commissioning. To prevent water entry in the package unit, use nitrogen gas or dry air for the airtightness test.

3.2.7 Lubricating Oil Charge

 TO select the lubricating oil to be used, refer to Section 4.1 "Lubricating Oil

(Refrigerant Oil)" in this manual.

 When refilling lubricating oil, ensure that it i s clean and does not contain foreign

matters.

 Be careful that air and water are not mixed in when refilling.  To ensure that the lubricating oil does not absorb air moisture, keep it indoors in

an airtight container until use.

3.2.7.1 Initial Charge of Lubricating Oil

Depending on the package unit configuration and operating condition, specify the procedure, method and amount of the initial charge of lubricating oil, and make sure to provide users of this product with such information.

In determining the procedure and work procedure of the initial charge of lubricating oil, please care oil is to be filled in the oil filter and oil cooler always.

3.2.7.2 Additional Charge of Lubricating Oil

Specify the procedure of the additional filling of lubricating oil based on the configuration of the package unit, and make sure to provide users of this product with the information.

3.2.8 Charge of Refrigerant

Depending on the use working fluid and equipment configuration of your package unit, specify the work procedure that considered safety enough, and conduct the refrigerant initial filling work accordingly.

In addition, specify the procedure of the additional filling of refrigerant, make sure to provide users of this product with the information.

3.2.9 Check after Installation

Depending on the package unit to which this product is installed, formulate the necessary confirmation items and methods for package unit after installation and conduct them accordingly before the commissioning. In addition, make sure to record and keep the results of your confirmation.

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4. Compressor and Package Unit Operation

Compound 2-stage Screw Compressor 4.1 Lubricating Oil (Refrigerant Oil) 1612LSC Speed Increaser Type

4-1

4. Compressor and Package Unit Operation

4.1 Lubricating Oil (Refrigerant Oil)

Lubrication management is very significant to keep the compressor in a good operating condition. Take the following notes when managing lubricating oil.

4.1.1 Precautions for Selecting the Lubricating Oil

 Selection of the lubricating oil should depend on the type of the refrigerant, the type of the

evaporator used with the compressor, and the conditions under which the compressor is operated. Also to be considered when selecting lubricating oil are the properties of the oil that include not only the viscosity but also such characteristics as compatibility in refrigerant, separability from refrigerant, low temperature fluidity, high temperature thermal stability, etc.

We therefore recommend contacting our sales offices or service centers for choice of a specified brand for your system.

 Lubricating oil used for compressors must have a viscosity appropriate for lubricating the

bearings and other components in the compressors. The viscosity to be considered in this case should be the viscosity the oil shows at the oil inlet of the compressor. The viscosity of the lubricating oil significantly changes depending on the type of the refrigerant used in combination with the lubricating oil. If the refrigerant dissolves in the lubricating oil (or the lubricating oil and refrigerant are compatible), the viscosity of the lubricating oil drops to a level remarkably below the level required for operation of the compressor under some operating conditions. On the contrary, if the refrigerant does not dissolve in the lubricating oil (or the lubricating oil and refrigerant are incompatible), the viscosity may become too high when the supply oil temperature is low. For this reason, the lubricating oil must be selected such that it is supplied to the compressor with an appropriate viscosity (kinematic viscosity of 13 to 40 mm

/s) in the

operating state.

 The circulation of the lubricating oil for the entire system must be considered. After lubricating

and cooling each part of the compressor, the lubricating oil is discharged with refrigerant gas. Most of the oil which is discharged from this compressor is trapped by the oil separator and is cycled to the compressor. A small quantity of refrigerant oil goes to the condenser and the evaporator. The lubricating oil is required to have sufficient fluidity and stability inside each part in the refrigerating cycle where temperatures differ.

 Note that some lubricating oils cannot be used depending on the combination with the

refrigerant. The following caution is an example case that is required especially attention.

 Be careful since polyolester synthetic oil (POE) must not be used with ammonia

refrigerant.

4.1.2 Recommended Lubricating Oils

When selecting lubricating oil, not only compatibility with refrigerant but also effects on O-rings must be considered. To prevent compressor malfunctions, we recommend the lubricating oil described below.

4.1.2.1 Recommended Lubricating Oils for Ammonia Refrigerant

 Polyalkylene Glycols (PAG) Based Synthetic Oil (compatible oil)

Brand Kinematic viscosity (40°C) mm2/s Manufacturer Type

JOMO Freol PN46 46 JX Nippon Oil and Energy Corporation PAG

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 Mineral oils (incompatible oils)

Brand

Kinematic viscosity

(40°C) mm2/s

Manufacturer Type

SUNISO 3GS 30 Sun Oil Naphthene

base

SUNISO 4GS 55 Sun Oil

REFOIL NS 3GS 30 Nippon Oil

GARGOYLE ARCTIC C HEAVY 46 Exxon Mobil

GARGOYLE ARCTIC 300 68 Exxon Mobil

CAPELLA WF46 46 Texaco

CAPELLA WF68 64 Texaco

CP-1009-32 34 CPI Hydrotreated

paraffinic base

CP-1009-68 69 CPI

REFLO 46A 46 Petro Canada

REFLO 68A 58 Petro Canada

CAPELLA PREMIUM 67 Texaco

RHT-68 68 Kluber

REFLO XL 59 Petro Canada

 Synthetic oils (incompatible oils)

Brand

Kinematic viscosity

(40°C) mm2/s

Manufacturer Type

Acemire 300 59 Acemire AB

Mycold AB68 53 BVA

ZERICE S46 46 Exxon Mobil

ZERICE S68 68 Exxon Mobil

BERREL FREEZE 46S 46 Matsumura Oil Co., Ltd.

CP-4700-32 31 CPI

CP-4700-68 56 CPI

Gold-Cold 300 53 Golden West

GARGOYLE ARCTIC NH68 64 Exxon Mobil PAO+AB

REFLO SYNTHETIC 68A 62 Petro Canada Gargoyle arctic SHC 224 Note 30 Exxon Mobil PAO Gargoyle arctic SHC 226(E) Note 68 Exxon Mobil

Note: Use only a seal of the standard BBSE type.

4.1.2.2 Oils for Systems Using Hydrofluorocarbon (HFC) refrigerants

 Polyolester synthetic oil (POE) for R404A, R507A and R410A

(compatible synthetic oil)

Brand Kinematic viscosity (40°C) mm2/s Manufacturer Type

SUNISO SL-68S 67 Sun Oil POE

EMKARATE RL68H 72 Lubrizol

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Compound 2-stage Screw Compressor 4.1 Lubricating Oil (Refrigerant Oil) 1612LSC Speed Increaser Type

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 Polyolester Synthetic Oil (POE) for R134a (Incompatible synthetic oil)

Brand Kinematic viscosity (40°C) mm2/s Manufacturer Type

JOMO Freol α100 107

JX Nippon Oil and

Energy Corporation

POE

 When using lubricating oil of a br and not described in this section, or when using

lubricating oil along with refrigerants or gases not described in this section, please contact us.

4.1.3 Change of Lubricating Oil Brand

When changing the lubricating oil brand in currently use for some reason, attention must be paid to the following points.

 The change of lubricating oil brand may cause problems in operating conditions and

the compressor. When changing the lubricating oil brand in use, make sure to contact us because appropriate steps must be surely followed.

 Package unit composition differs depending on the characteristics of lubricating oil

(compatible/incompatible with refrigerant). As a general rule, changing compatible oil to incompatible oil or vice versa is not allowed.

 Lubricating oil contains various additives to fulfill necessary lubricating conditions. Types of

additives and their mixing ratio depend on each oil brand. We, therefore, recommend to avoid mixed use of different brands of lubricating oil. If mixed brands of lubricating oil are used, the different additives in the lubricating oil may react with each other and produce foreign substances like slurry.

 If it is necessary to change the brand of lubricating oil, collect as much as oil as possible from

the compressor as well as from the condenser, evaporator, and all other refrigerating unit components before charging the new lubricating oil. After 100 to 200 hours of operation, replace the oil again.

 If lubricating oil manufacturers differ, contact both of them and inquire whether the changing is

appropriate. The same confirmation is required for changing the brand even if it is of the same manufacturer.

 There is no problem in changing the viscosity level within the same brand. However, make sure

that the viscosity grade will not cause problems during operation (Example ： SUNISO 3GS→SUNISO 4GS).

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4.1.4 Precautions for Handling lubricating Oil

 When refilling lubricating oil, ensure that it is clean and does not contain foreign matters.

 Be careful that air and water are not mixed in when refilling.

 To ensure that the lubricating oil does not absorb air moisture, keep it indoors in an airtight

container until use.

4.1.4.1 Precautions for Handling Polyalkylene Glycol (PAG)

PAG oil is much more hygroscopic than mineral oils and any moisture mixed in the oil may lead to rust, corrosion and wear within the package. When handling PAG oil, pay special attention to the following points.

 Do not perform oil charging in rainy weather or at a place with high humidity to prevent

absorbing moisture.

 Before charging, remove as much moisture as possible from the system by exhausting it with

a vacuum pump for a sufficient length of time and leaving the system in vacuum condition overnight.

 Do not open the lid of pail (oil container) until just before charging. Once the can is opened,

finish the oil charge as quickly as possible. (Finish the charge of a single can of oil within 15 minutes.)

 Cover any gaps between the pail opening and the charge hose so that foreign substances or

moisture cannot enter. A more effective way is to substitute any space inside the pail with nitrogen gas.

 Always charge all oil from the pail. Even if some oil remains, do not use it subsequently.  If any oil drops on a painted surface, wipe it away as soon as possible. Otherwise the paint

may come off.

4.1.4.2 Precautions for Handling Polyolester (POE) Oil

This type of oil has high hygroscopicity as polyalkylene glycol, and also exhibits hydrolyzability under high temperature environments. Moisture entry must be avoided. Therefore, special attention must be paid as with PAG when handling POE.

 Finish the charging in as short a time as possible after opening the pail to minimize exposure

to air.

 Make sure that all oil in a pail is used in a single charging. Any remaining oil must be stored

indoors with the can lid closed tightly. Do not attempt to store it for a long time.

 Because POE can hydrolyze, make sure to perform an oil analysis regularly in the package to

see if any abnormal conditions are present.

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4.1.5 Lubricating Oil Management Criteria

Lubricating oils that are managed by the criteria are classified into the following categories:

(1) Synthetic oils: Polyalkylene glycols (PAG) (2) Mineral oils: Naphthenic base oils and paraffinic base oils (3) Synthetic oils: Alkylbenzene (AB) and Polyalphaolefine (PAO) (4) Synthetic oils: Polyolesters (POE)

 Oil sampling and analysis is recommended every six months.  If the following control criteria are not satisfied, replace the oil.

◆ Note that the water content of PAG shall be excluded from the above oil replacement criteria.

Refer to the Note in the following table.

The analysis items and the criteria are shown in the following tables. Please note that these management criteria may be changed without notice.

 Table 4-1 Synthetic Oil (PAG)

Item Criteria

(a) Color phase ASTM color scale: 4.0 or less (b) Total acid number (TAN) 0.1 mg KOH/g or less (c) Kinematic viscosity Within ±10 % from that of fresh oil (d) Water content 2000 mass ppm or less Note (e) Degree of contamination Degree of contamination measured by mass method (Millipore

value) shall be 15 mg/100 mL or less

 Table 4-2 Mineral Oil and Synthetic Oil (AB, PAO)

Item Criteria

(a) Color phase ASTM color scale: 6.0 or less (b) Total acid number (TAN) 0.3 mg KOH/g or less (c) Kinematic viscosity Within ±15 % from that of fresh oil (d) Water content 100 mass ppm or less (e) Degree of

contamination

Degree of contamination measured by mass method (Millipore value) shall be 15 mg/100 mL or less

 Table 4-3 Synthetic Oil (POE)

Item Criteria

(a) Color phase ASTM color scale: 4.0 or less (b) Total acid number (TAN) 0.2 mg KOH/g or less (c) Kinematic viscosity Within ±10 % from that of fresh oil (d) Water content 200 mass ppm or less (e) Degree of

contamination

Degree of contamination measured by mass method (Millipore value) shall be 15 mg/100 mL or less

Note: Synthetic oils (compatible with ammonia) are so highly hygroscopic that they can absorb

moisture at the time of sampling. In addition, the ammonia content they have absorbed may be detected as the water content at the time of the analysis, making it difficult to precisely measure the water content. Thus, use the criterion value only as a reference.

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Compound 2-stage Screw Compressor 4.1 Lubricating Oil (Refrigerant Oil) 1612LSC Speed Increaser Type

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4.1.6 Lubricating Oil Replacement Timing

4.1.6.1 After Starting the Initial Operation

As the oil can easily be contaminated and degraded relatively quickly during the initial operation due to scales and deposits remaining in piping and vessels, be sure to sample and analyze the oil after 500 hours of operation.

If it is found as a result of the analysis that the criteria given in Tables 4-1 to 4-3 are not satisfied, the oil must be replaced.

4.1.6.2 During Normal Operation

Lubricating oils will degrade gradually as the system is operated over time. The rate of degradation depends on the operating condition, type of oil and amount of foreign matters

and moisture contained in the oil. The lubricating oil must be sampled and analyzed every six months. If it is found as a result of the

analysis that the control criteria given in Tables 4-1 to 4-3 are not satisfied, the oil must be replaced. If the oil filters are frequently clogged or the oil color quickly becomes darker and unclear, replace the

oil after removing the cause of the problem.

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Compound 2-stage Screw Compressor 4.2 Precautions for Operation 1612LSC Speed Increaser Type

4-7

4.2 Precautions for Operation

If the package unit is used in the refrigeration cycle, please keep in mind the contents of this section in particular.

4.2.1 Prevention of Liquid Flow-back

Liquid flow-back is a phenomenon where refrigerant that did not completely evaporate with the gas reaches the compressor. Liquid flow-back may cause insufficient lubrication of the compressor, abnormal vibrations and noises, and abnormal foaming of lubricating oil (too much oil loss). To prevent liquid flow-back, properly adjust the expansion valve of each liquid cooler. For details, refer to Chapter 6 "Troubleshooting" in this manual.

4.2.2 Purging of Non-Condensable Gases

 Some types of refrigerants emit bad smells or toxic gases. Make sure to ventilate

the air during work.

If there is a leak on the low-pressure side of the refrigeration cycle, air may enter the package unit. If non-condensable gas like air enters the unit, the condensing pressure rises and the energy

consumption increases. This leads to uneconomical operation. Follow the procedure below to check for non-condensable gases.

1. When the compressor is stopped, allow the cooling water to flow to the unit's condenser for at

least 15 minutes. Check the condensing pressure by using the pressure gauge of the compressor.

2. Check the cooling water temperature.

3. Compare the condensing pressure checked in step 1 above with the refrigerant saturation

pressure that depends on the cooling water temperature (as shown in the table b elow).

T able 4-4 Ty pical Refrigerant Temperature and Saturation Pressure

■ Unless otherwise noted, the pressure unit MPa represents the gauge pressure in this manual.

4. When the pressure inside the condenser and the refrigerant saturation pressure that depends on

the cooling water temperature are approximately equivalent, non-condensable gases do not exist. When the pressure inside the condenser is 0.05 MPa or more higher than the refrigerant saturation pressure that depends on the cooling water temperature, there is a possibility of non-condensable gases entering the unit. In that case, purge the non-condensable gases from the condenser .

T emperature °C

Pressure MPa

Ammonia R404A R507A R410A R134a

0 0.328 0.509 0.523 0.699 0.192 4 0.396 0.590 0.606 0.807 0.237

8 0.472 0.678 0.696 0.924 0.287 12 0.557 0.775 0.795 1.053 0.342 16 0.652 0.881 0.903 1.193 0.403 20 0.756 0.996 1.021 1.346 0.471 24 0.871 1.121 1.148 1.513 0.545 28 0.998 1.256 1.286 1.693 0.626 32 1.137 1.401 1.435 1.887 0.714 36 1.289 1.559 1.595 2.098 0.811 40 1.454 1.728 1.768 2.324 0.916

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Compound 2-stage Screw Compressor 4.3 When Stopping the Compressor for a Long Time 1612LSC Speed Increaser Type

4-8

4.3 When Stopping the Compressor for a Long Time

When stopping the compressor for a long period of time, make sure to perform the following steps.

 Turn off the motor main power.

 Turn off the heater power and control panel power.

 Close the suction and discharge side shut-off valves.

If the operation stop period is 1 month or longer, perform the following checks.

 Operate the oil pump for 10 seconds per week.

After that, rotate the compressor shaft (10 rotations or more).

 Measure the package unit pressure once per month.

 Check for refrigerant leakage once per month.

When restarting the compressor after an operation stop period of 1 year or longer, check the system for refrigerant leak and analyze the lubricating oil.

If it is found as a result of the analysis that the control criteria given in this Chapter, Section 4.1.5 Tables 4-1 to 4-3 are not satisfied, the oil must be replaced.

Also check the motor insulation resistance. Supply power to the oil heater at least 1 day before operation start. Before starting the operation, confirm that the refrigerant is not condensed in the package unit by

checking the package temperature and pressure.

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5 Maintenance and Inspection

Compound 2-stage Screw Compressor 5.1 Precautions for Maintenance and Inspection 1612LSC Speed Increaser Type

5-1

5 Maintenance and Inspection

5.1 Precautions for Maintenance and Inspection

When reading this Section, also refer to Section 1.1 in this manual Chapter 1.

 When entering the machine room for maintenance ser vices, ensure that sufficient

ventilation has been started and measure the oxygen concentration so that there is no risk of oxygen deficiency. The ventilation must be continued steadil y until the work is completed.

 For performing the inspection work, be sure to prepare safety shoes, protective

glasses, gas mask and other proper protective equipment and do not fail to use them whenever they are required.

 After stopping the machine and before working on a regular inspection or overhaul,

be sure to shut off the main motor power, control power, and other power to each equipment and valve. After they are shut off, be sure to make the switches inoperable by others. Also, be sure to attach notification tags to prohibit operation (lock-out/tag-out).

 When any manual stop valve has been closed, be sure to make the valve

inoperable by others and put a notification tag to prohibit the operation (tag-out).

 When the compressor is to be overhauled, check that the internal pres sure of this

product is at the atmospheric pressure before starting the work.

 When using lifting devices, e.g. a crane, etc. and/or lifting tools, ensure that they

can sufficiently withstand the load.

 When lifting a heavy load object, do not allow anyone’s body to put under it.  The work to turn each power supply ON/OFF or operate a lifting unit must be

exclusively performed by qualified personnel.

 When using electric tools, ensure that they are properly managed in accordance

with each instruction manual. Especially before using and while using, be sure to follow the care instructions on the safety of each instruction manual.

 Be sure to use only genuine parts for replacement. Using parts that are

not genuine can cause damage to this product or other devices during operation.

 Do not convert or modify this product or its components without prior permission

from MAYEKAWA. Otherwise, it can lead to an unexpected accident.

 Exercise sufficient care for handling a heavy load, and use such a lifting device as a

crane or work with an adequate number of personnel commensurate with the magnitude of the weight. Also, be sure to use stud bolts (safety retention bolts) and other support tools for the work. Neglecting the above warning can lead to low back pain of the worker or injury due to dropping of the parts.

 If two or more people are to work together, be sure to clearly define the work

procedures to share a common understanding among all workers before performing the work.

 Not only the work to turn each power supply ON/OFF or operate a lifting device, but

also any type of work requiring qualification must be exclusively performed by qualified personnel.

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5 Maintenance and Inspection

Compound 2-stage Screw Compressor 5.1 Precautions for Maintenance and Inspection 1612LSC Speed Increaser Type

5-2

 When checking the operation data of units and executing other daily maintenance

services, pay particular attention to avoid touching the area heated to a high temperature causing skin burns or inadvertently moving the handle of a valve leading to an erroneous operation.

 In the disassembly/inspection workplace, secure a sufficient space for temporary

storage of the removed parts and tools, replacement parts, and for the disassembling work as well as safety passages, and then put up necessary off-limit signs.

 In the workplace, secure a sufficient space and refrain from putting tools directly on

the floor or from haphazardly laying wires.

 Keep the floor clean all the time. Leaving the floor smeared with oil and the like

causes it to be slippery and may result in the fall and injury of personnel. Thus, do not leave it but wipe it off right away.

 Make sure that the temperature of the high temperature sections such as head

covers and discharge lines has been cooled down to normal ambient temperature, before working on them.

 When disassembling and reassembling the compressor, use the specified tools

properly. Before starting to use those tools, gain the full understanding of their characteristics and the method for use.

 During the maintenance service, keep the tools clean all the time. Using those tools

smeared with oil increases the risk of slip and fall, leading to an injury. Also during the service, there is a risk of foreign matters intruding inside the compressor to cause its damage.

 Parts are slippery with oil. Fully watch out for the risk of any object falling down.

Pay attention to any parts falling down, which could lead to personal injury.

 Before disassembly, inspections, and handling of the compressor, sufficiently

understand the disassembly and assembly procedures. This manual is not intended to provide complete disassembly and assembly procedures for the compressor. Instead, it describes only the important points in relation to the maintenance service of the compressor.

 If complete disassembly and assembly of the compressor are required, please

contact your nearest sales office or service center of MAYEKAWA.

 When removing a part, be careful not to damage it.  Place the removed parts on a clean workbench in an orderly manner.  For cleaning parts, use kerosene and/or machine parts cleaner.  Washed parts shall be dried by compressed air or wiped up using clean cloth. Do

not use synthetic textiles or woolen textiles to prevent fibers from attaching the parts.

 When separating the assembled compressor casings, sometimes it is difficult to

separate them due to the gasket stuck. In such a case, never hammer in a screw driver or flat chisel into the gap. Screw jack bolts using the screw holes to separate the casing each other. When some gap is observed between them, use a scraper to remove one side of the gasket from the surface.

 Removed bolts from each part should be classified into each used section to

prevent confusion.

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5.2 Maintenance and Inspection List

5.2.1 Daily Management

As daily management, check the items listed in Table 5-1 "Daily Inspection Items" and record the results.

Logging these operation data on a daily basis aid in finding out any abnormal conditions of the compressor. This is significantly effective in preventing compressor failures.

It is particularly important to check whether the temperature/pressure correlations related to the refrigerant evaporation and condensation is proper. This makes it possible to quickly find out problems in the compressor or the system.

If a failure or accident should occur in the compressor or the system, the operation logbook will help determine the cause and take prompt and proper actions.

T able 5-1 Daily Inspection Items

Inspection Items Inspection Contents Check Points and Actions

Compressor

Operating hours hr Total operating hours  Judgment of periodic

maintenance timing

Suction pressure

MPa

Note 1

Difference from the set value of evaporation temperature equivalent pressure

 Contamination on the cooling

pipe surface

 Temperature, flow rate, etc. of

the object to be cooled

Intermediate pressure MPa Pressure difference from

rated operation (normal value)

 If it is too high， check high-

stage. If it is too low check low-stage.

Discharge pressure Mpa Difference from cooling water

temperature equivalent condensing pressure

 Contamination on condenser

cooling pipes

 Non-condensable gases mixed

into the system

 Quantity, temperature, etc. of

cooling water

Oil supply pressure MPa Difference from discharge

pressure

 Whether differential pressure is

decreasing

 Operation with liquid flow-back  Whether compressor parts are

worn

Oil filter pressure loss MPa Pressure difference between

oil filter inlet and outlet

 Contamination of lubricating oil  Clogging of oil filter element

Suction temperature °C Whether within upper and

lower limits

 Temperature, flow rate, etc. of

the object to be cooled

Degree of superheat for suction

°C Whether degree of

superheat is proper

 Adjust expansion valve  Insufficient refrigerant flow

Intermediate temperature

°C Whether within upper and

lower limits

 Adjust intermediate expansion

valve

Discharge temperature

°C Whether within upper limit  Non-condensable gases mixed

into the system

 Oil supply temperature,

insufficient oil supply

 Compressor failure

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Inspection Items Inspection Contents Check Points and Actions

Oil supply

temperature

°C Whether within upper and

lower limits

 Contamination on cooling pipes

of oil cooler Capacity control Indicated load

Whether operation is normal  Damage to solenoid valve coil

 Improper adjustment of manual

control valve of

electromagnetic assembly Leak from mechanical seal

ml Leak per hour  Mechanical seal failure

Noise and vibration Abnormal noise/vibration  Compressor failure

Others

Motor current A Whether it is higher than the

current at test run

 Compressor/Motor failure

Oil level of oil separator

- Oil level  Oil loss  Replenish oil

Fluid level in the receiver

- Fluid level  Replenish refrigerant

Check for refrigerant leak

leak or not  Inside the machine room and in

the facility on the load side

Note 1 : Unless otherwise noted, the pressure unit MPa represents the gauge pressure in this

manual.

 Daily Maintenance Items

1. Lubrication oil level

When the oil level in the oil separator reaches the lower limit, charge lubricating oil by referring to the instruction manual of the unit.

2. Replacing oil filter element

When the differential pressure between the inlet and out let ports of the oil filter exceeds 0.1 MPa, replace the oil filter element. At the beginning of the operation, the differential pressure of the oil filter may increase quickly.

3. Cleaning of suction strainer

When the compressor operating hours exceeds 500, check the suction strainer. If a temporary filter is installed for the initial stage of operation, remove it. At the beginning of the operation or after periodical check, the differential pressure between the front and back of the suction strainer may increase quickly. If the differential pressure becomes large, check and clean the suction strainer.

4. Lubricating oil leak rate from mechanical seal

If much oil leaks from the mechanical seal, determine the leak rate per hour. The following table shows guidelines for allowable leak rate and the rate at which inspection must be done. If any problem (damage, etc.) is found in mechanical seal, replace the mechanical seal.

T able 5-2 Guideline for Leak from Mechanical Seal

1612LSC

Allowable leak rate ≤ 3 ml/hr

Rate at which inspection must be done ≥ 9 ml/hr

Note: The specifications above are just guidelines. They are not guaranteed values.

5. Contamination on the cooling water side of the cooling pipes of condenser and oil cooler

Clogging and contamination of the cooling pipe is largely affected by the quality of cooling water. When the oil temperature and discharge pressure gradually rise during the initial stage of operation, inspect and clean the cooling water side of oil cooler and condenser even when the time has not yet come at which inspection must be done.

Compressor

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5.2.2 Periodic Inspection

Conduct inspection for the following items according to the specified intervals. In addition, observe relevant laws and regulations on the inspections and recording of the results that

are provided for other related items such as any safety devices (e.g. gas leak detectors), or other utility (gas/electricity) protection devices that constitute the cooling package unit together with the compressor.

Table 5-3 Periodic Inspection Items

Item Inspection interval and Con ten t Remarks

Pressure gauges/ pressure sensors

Yearly inspection

Thermometers/ temperature sensors

Yearly inspection

Protection devices and safety valves

Yearly inspection

Suction strainer Inspect after 500 hours from the start

of operation.

If the differential pressure between the front and back of the suction strainer increases, check and clean the suction strainer.

Yearly inspection and cleaning

Lubricating oil Analyze lubricating oil after 500 hours

from the start of operation.

Replace the oil if the analysis result does not satisfy the control criteria given in Section 4.1.5.

Analyze oil every 6 months.

Oil filter element Yearly replacement Replace the filter element if the

differential pressure between the inlet and outlet ports of the oil filter exceeds 0.1 MPa.

Cooling water side of oil cooler

Yearly inspection Clean if excessively contaminated.

Cooling water side of condenser

Yearly inspection Clean if excessively contaminated.

Mechanical seal Inspection every year or every 8000

hours of operation Note*

To be replaced if any abnormality is found If it is difficult to stop equipment except for scheduled inspections, replace the part at each inspection.

Coupling Inspection every year or every 8000

hours of operation Note*

Note*: Inspect the machine per period or operating hours, whichever comes first.

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5.2.3 Guidelines for the Timing of Compressor Overhaul

The compressor overhaul interval is largely affected by the compressor operating conditions, type and status of refrigerant and oil, and the system/equipment in which the compressor is operated.

The table below shows the recommended interval of overhaul, as a guideline.

T able 5-4 Guidelines for the Timing of Overhaul Based on the Conditions of Use

(standard pa ckage)

Category of operating condition

Application

example

Guideline for the overhaul timing

Relatively stable operating condition

Cold storage and

refrigeration

Every 5 years or 40,000 operating hours

Relatively variable operating condition Ice maker/chiller Every 4 years or 30,000 operating hours

Frequently started/stopped, and relatively variable operating conditions

Heat pump Every 3 years or 20,000 operating hours

Note 1: The above guidelines are only applicable when the compressor is operated within the operation

limits specified separately. (Refer to Section 2.3.2 "Operation Limits" in this manual.)

Note 2: The above guidelines are only applicable when the compressor undergoes daily and periodical

inspections specified separately. (Refer to Section 5.2.1 "Daily Management" in this manual.)

Note 3: Inspect the compressor at the intervals of specified period or operating hours, whichever comes

first.

Note 4: The above guidelines do not constitute any warranty.

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5.3 Compressor Disassembly Preparation

Although screw compressors are very reliable machines, it is still necessary to perform overhaul to inspect internal parts after a certain pe riod of operation. This chapter 5 explains the essential points of disassembly methods, where to inspect on parts, and reassembly procedure of the compound 2-stage screw compressor 1612LSC speed increaser type.

In principle, overhauling of the screw compressor that requires complete disassembly should be performed in the maintenance factory. If you must do the overhaul work at the installation site due to unavoidable reasons, use the methods described in the following paragrap hs.

However, please note that regular overhaul work requires removal of the compressor from the base frame. And then, the compressor should be placed on a work bench which has properly size area to disassembling the compressor.

When moving the compressor from the unit base to the workbench, be sure to follow the instructions given in Chapter 3, Section 3.1 "General Installation Precautions" and Section 3.2.3 "Transportation" of this manual.

Note that some parts name given in the text of this manual is followed by a number enclosed in square brackets [ ], which indicates the part identification number given in assembly sectional views or development views.

5.3.1 Disassembly Tools and Workplace

Prepare necessary disassembly tools for the compressor by referring to Section 7.5 "Disassembly Tools" in this manual Chapter 7.

In addition, prepare other necessary tools and materials including general hand tools, GC (green carbonite) grinding stones, sandpapers of #80 to #100, about #400 to #800 sandpapers, parts cleaner, lubricating oil, oilcan, empty can to receive drain oil, waste, etc.

If the overhaul work is to be done with the compressor removed from the installation base, prepare the work bench whose size is at least around 1.5 times the length and the width of the compressor.

In addition, a special stand for the compressor is required in order to safely perform the removal/fastening of bolts and plugs on the bottom side of the compressor. Refer to Section 5.3.5 of this chapter.

To the extent possible, choose a dry and clean workplace free from sand or dust. Note that a sufficient space is required around the compressor. In addition, it is necessary a temporary storage place for disassembled parts.

5.3.2 Replacement Parts

Prepare the genuine parts for replacement. Parts listed in Table 5-5, we recommend to be replaced on the occasion of each compressor overhaul. When ordering parts, be sure to inform the (a ) model name, (b) serial number, (c) part name, (d) code

No. and (e) quantity required, to our sales offices or service centers. In particular, if the serial nu mber (b) is unkn own, the details of the applicable design and manufacturing

specifications cannot be identified, and thus it becomes difficult to choose correct p arts. So, make sure to inform the (b) serial number to us.

T able 5-5 Replacement Parts of 1612LS**C Speed Increaser Type Overhauling

P/N Part Name Code No. Remarks Q’ty.

6-1 Gasket, Suction Cover (1)

CS00600-160N

6-2 Gasket, Suction Cover (2)

CS00600-1612CN 1

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P/N Part Name Code No. Remarks Q’ty.

12-1 Gasket, Bearing Head (1)

CS01200-160N 1

12-2 Gasket, Bearing Head (2)

CS01200-1612CN

17-2 Gasket, Bearing Cover (2)

CS01700-1612CN

23 Gasket, Balance Piston Cover

CS02300-1612CN 1

27-1A Main/Side Bearing (1) A

CS02700-1612C3 1

27-1B Main/Side Bearing (2) B

CS02800-1610C1 1

27-2 Main Bearing (2)

CS02700-125 2

28-1 Main/Side Bearing (1)

CS02800-1610C1 2

28-2 Side Bearing (2)

CS02800-125 2

29-1A Snap Ring (1) A C Type Internal H112 NG11-112

To be replaced if any abnormality is found.

29-1B Snap Ring (1) B C Type Internal H102 NG11-102 3

29-2 Snap Ring (2) C Type Internal H80 NG11-080 4

30 Balance Piston

CS03000-1612C

To be replaced if any abnormality is found.

32 Snap Ring S40 external

NG12-040

To be replaced if any abnormality is found.

33 Balance Piston Sleeve

CS03300-160

To be replaced if any abnormality is found.

35 O-ring JIS B 2401 G95

PA12-095

37 Snap Ring C Type Internal H102 NG11-102

To be replaced if any abnormality is found.

38-1A Thrust Bearing (1) A

CS03800-1612CP

38-1B Thrust Bearing (1) B

CS03800-160P 1

38-2 Thrust Bearing (2)

CS03800-125P

39-1A

Lock Nut (1) A AN14 NG31-014

To be replaced if any abnormality is found.

39-1B

Lock Nut (1) B AN12 NG31-012 2

39-2

Lock Nut (2) AN09 NG31-009 2

40-1A

Lock Washer (1) A AW14 NG32-014 1

40-1B

Lock Washer (1) B AW12 NG32-012 2

40-2

Lock Washer (2) AW09 NG32-009 2

49 O-ring JIS B 2401 G90

PA12-090

50 Oil Seal

CS05000-160VD

52 Gasket, Seal Cover

CS05200-160N

59 O-ring JIS B 2401 P16

PA11-016

63 O-ring JIS B 2401 G95

PA12-095

65 O-ring JIS B 2401 P75

PA11-075

66 Cap Seal BE75

CS06600-125 1

68 Guide Pin Φ3×8

NE2503-008

To be replaced if any abnormality is found.

69 Lock Nut (1) AN05

NG31-005

To be replaced if any abnormality is found.

70 Lock Washer AW05

NG32-005

71 Lock Nut AN06 NG31-006

To be replaced if any abnormality is found.

72 Lock Washer AW06 NG32-006 1

73 O-ring JIS B 2401 P21

PA11-021

75 O-ring JIS B 2401 G85

PA12-085 1

77 Indicator Cam

CS07700-1610C

To be replaced if any abnormality is found

78 Ball Bearing, Indicator Cam #6000

CS07800-200

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P/N Part Name Code No. Remarks Q’ty.

79 Snap ring C type External S10

NG12-010

82 V-ring, Indicator Cam VH10 NBR

CS08200-200B

83 Spring

CS08300-200 1

86 O-ring JIS B 2401 P16

PA11-016

89 O-ring JIS B 2401 P16

PA11-016

93-1 Gasket, Suction Flange (1)

CR72000-125N MYK 125A(5") 1

93-2 Gasket, Suction Flange (2)

CR72000-080N MYK 80A(3")

96-1 Gasket, Discharge Flange (1)

CR72000-080N MYK 80A(3")

96-2 Gasket, Discharge Flange (2)

CR72000-065N MYK 65A(2"1/2) 1

100 Mechanical Seal Assembly BBS-E

CS10002-160EBS

To be replaced if any abnormality is found

125 Set of Micro-switch 125L

CS1259-C

To be replaced if any abnormality is found

129 Potentiometer 1612 1k with Wire CS1299-J

To be replaced if any abnormality is found.

202 Bevel Gear ID 6 mm

CS20100-1612C6

To be replaced if any abnormality is found

- Gear Coupling Assembly (Current Type) CS1519-J

To be replaced if any abnormality is found.

159

Knurled Cup Point Socket Set Screw with anti-loosening

NA83606-015

To be replaced if any abnormality is found.

160 Lock Nut AN8

NG31-008

To be replaced if any abnormality is found.

161 Lock Washer AW8

NG32-008

163 O-ring JIS B 2401 G25

PA12-025

165 O-ring JIS B 2401 P21

PA11-021 1

170 Gasket, Speed Increaser Gear Casing CS17000-1612CN 1

172 Gasket, Speed Increaser Gear Casing Cover CS17200-1610CN 1

183 Side Bearing Speed Increaser Driven Gear CS02700-125 1

185 Roller Bearing CS18500-1612C 1 186 Snap Ring C Type Internal H110 NG11-110

To be replaced if any abnormality is found

187 Snap Ring C Type External S60 NG12-060 1 189 Thrust Bearing CS03800-200P 1

193 Lock Nut AN13 NG31-013

To be replaced if any abnormality is found

194 Lock Washer AW13 NG32-013 1

197 O-ring JIS B 2401 P32

PA11-032

237-1A Tortional Slip Washer (1) A

CS23700-1612CB 1

237-1B Tortional Slip Washer (1) B

CS23700-160

237-1C

Tortional Slip Washer (1) C

CS23700-200

237-1D

Tortional Slip Washer (1) D

CS23700-250 1

237-2 Tortional Slip Washer (2)

CS23700-125

269 Lock Nut AN17

NG31-017

To be replaced if any abnormality is found

270 Lock Washer AW17

NG32-017

● The part code of the O-ring is the one assigned to NBR which is standard material.

When the material of the O-ring is other than NBR, a different part code is used for

each material.

If you are using O-rings made from other than the standard material, please contact

us when placing an order.

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5.3.3 Refrigerant Gas Recovery

At the time the compressor operation is stopped, the pressure inside the compressor is still high. As such, it is necessary to lower the pressure down to the atmospheric pressure before starting the disassembly process. To do this, there are the following methods for example. Perform your recovery work in an appropriate manner considering site conditions, requirements of regulatory laws and regulations.

 By using the bypass valve, release the high pressure gas in the package unit to the low pressure

side.

 If there is another compressor unit to which a permanent bypass line is connected,

operate the

other compressor and lower the pressure through the bypass line.

 Operate the refrigerating system, and close the fluid supply master valve to turn the gas into liquid,

and recover the liquid at the receiver.

 By using a refrigerant recovery machine, recover the liquefied refrigerant in the receiver.

In using either method, prepare a working flow sheet of the system beforehand. Check the valves to be controlled during the recovery work, according to the method to be used, by comparing them with the ones in the flow sheet, and clearly note the valves to be operated, other connected devices, and tubes on the flow sheet.

Two flow sheets must be prepared: one at the foreman and the other for posting in the workplace. In addition, prepare a work procedure document for the refrigerant recovery work to reflect the actual

conditions of the workplace, and sufficiently share the work details among all the coworkers through checking and confirmation before actually starting the work.

The gas mask and other protective gears required at each stage of refrigerant recovery work must be prepared before starting the work.

 Before the work, be sure to check and communicate the work details and procedure

among all coworkers, and carry out hazard prediction activities based on the information shared. Neglecting to do this will increase the risk of on-the-job accidents and injuries to a considerable level.

 After closing (opening) a valve for work, conduct lockout/tagout to prevent it

from being handled accidentally during work.

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5.3.4 Removing Parts Connected to the Unit

 If there is residual high-pressure refrigerant gas or oil dissolved in the

refrigerant, the gas and oil may blow off when closed valves (components) are opened. This may result in injury such as frostbite and loss of vision. Always check and confirm the pressure in the compressor, before opening any pipe connections and valves.

When removing the compressor from the mounting base frame, the following parts must be disconnected beforehand:

(1) The coupling joining the compressor and driving machine

(2) The compressor’s suction piping flange and discharge piping flange (if the suction strainer is

connected directly to the compressor, remove the strainer too), and the intermediate piping connecting the low-stage discharge port to the high-stage suction port

(3) Compressor lubrication piping (journal lubrication: 2 places, oil injection: 1 place, capacity control

loading/unloading: 1 place each)

(4) Capacity control operation electric wiring

(Depending on the situation of the workplace, unloader indicator assembly may be separated, with the wiring left as it is. Refer to "5.7.15" in this manual.)

(5) Bolts for attaching compressor (leg bolts)

When removing oil lines from the compressor, there is possibility of gas and oil blowing out caused by residual gas pressure. Moreover, any residual oil in the pipe will flow out. To be prepared for this, either check the amount of oil outflow by slightly loosening the pipe joint or drain the oil from the oil temperature gauge at the supply header before removing the pipe.

Work carefully in particular when disassembling the unloader cylinder block since there is residual pressure and oil fills in the unloader cylinder. Moreover, prepare a larger volume container than the unloader cylinder volume to receive oil flowing out.

For easy reconnection, disconnected electric wires should be properly marked for identification. Any wrong reconnection may result in a startup failure or inability to operate the capacity control mechanism.

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5.3.5 Compressor Removing and Lifting

 The work to lift up or move the compressor must be performed by a qualified operator.  Make sure that the lifting equipment and wires have sufficient load capacity for the

compressor before starting the compressor lifting work.

 Never try to perform disassembly or assembly while the compressor is lif ted in the air.

Since the suction piping is located immediately above the compressor, hold it up or partially remove it before lifting the compressor.

For the lifting positions of the compressor, refer to Figure 3-1 in page 3-3 of Chapter 3 in this manual.

If the planned overhaul work includes separation between low-stage and high-stage blocks of the compressor, place the compressor on a special stand as shown in Photo 004 and then remove

eight or more hexagon head cap screws around the bottom flange part. Never try to remove these bolts while the compressor is lifted in the air. Note that these bolts cannot be removed

once the compressor is placed on the work bench.

Lifting the Compressor Lower Bolts for Tightening Rotor Casing

5.3.6 Removing Oil from Inside the Compressor

Since there is a large quantity of oil inside the compressor, remove it beforehand. There is a plug [10] under the suction cover [5-1] and a plug [15] under the bearing head [11-1]. Most of the oil will flow from these plug holes. The remaining oil will flow onto the work bench during disassembly. Main locations remaining oil are a) inside the unloader cylinder, b) inside the balance piston cover, c) inside the seal cover [51], and d) inside the suction cover [5-1]. Prepare a tray and cloth for oil that spills during disassembly.

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5.4 Disassembly and Inspection

Generally, compressors are disassembled in the order shown in Figure 5-1 Illustrated Disassembly Sequence but the order in the figure is just an example and the actual order may differ according to individual situations. For instance when overhauling it is no problem to start separation of high-stage part from low-stage part after removing the compressor from the unit frame and putting it on the work bench prepared beforehand. In addition, it is often the case that the disassembly of unloader cover/unloader cylinder part from mechanical seal part is performed in the reverse order of shown in the Figure 5-1.

Shown in the steps in the Figure 5-1,

① through ⑤ ,⑩ and ⑪, you can disassemble the

compressor with the compressor attached on its frame.

When conducting steps

⑦ through ⑲, the compressor should be removed from its frame and placed

on a work bench prepared in advance. When disassembling high-stage or low-stage side only, start from step ⑦ and disassemble necessary parts only. Parts that have no problem should be left as they are. Do not disassemble such parts unless during periodic inspection. Since it is difficult to completely eliminate the risks of performing inaccurate work at the field, disassemble the minimum required parts only.

Table 5-6 Disassembly Order of Compressor (examples)

Part for Disassembly

Disassembly Order (Refer to Figure 5-1)

(1) Shaft seal block

①－②

(2) Unloader indicator

③

(3) Unloader cylinder cover

③－④

(4) Unloader piston and unloader cylinder

④

(5) Speed increaser gear casing cover

③

(6) Speed increaser gear casing

⑥

(7) Separating high-stage and low-stage

⑦

High-stage (8) Gear coupling

⑦－⑧

(9) Thrust bearing

⑦－⑧－⑨

(10) Balance piston cover

⑩－⑪

(11) Balance piston

⑩－⑪

(12) Suction cover casing and main bearing

⑩－⑪－⑫

(13) Rotor and main rotor casing

⑬－⑭

(14) Bearing head and main bearing

⑭

Low-stage (15) Thrust bearing

⑮

(16) Gear coupling

⑯

(17) Suction cover casing and side bearing

⑰

(18) Rotor and main rotor casing

⑱－⑲

(19) Bearing head and main bearing

⑲

(20) Unloader slide valve and guide block

⑲

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Figure 5-1 Disassembly Order Description

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5.4.1 Shaft Seal Block

P/N Part name

101 Mating ring

Mating

ring

102 Insert lock pin 103 O-ring 109 Seal collar

Rotating

ring

111 Seal collar set screw

112 O-ring

Figure 5-2 Details of BBSE Type Mechanical Seal Assembly

5.4.1.1 Disassembly

a) Of the eight hexagon socket head cap screws [53] on the seal cover [51], remove six screws leaving

two diagonally opposite screws.

b) Slowly loosen the remaining two screws by turns so that they stay even. After a certain amount of

loosening, the seal cover of the mechanical seal will be pushed by the spring and a gap will appear. A gap will not appear if the gasket is stuck. In that case, push the seal cover by screwing the M8

eyebolts into the seal cover’s service holes. c) Use a container to catch the oil that will flow out through the gap. d) Pull out the seal cover keeping it parallel with the shaft (rotor axis). The mating ring inside the seal

cover is attached with an O-ring [103]. Ensure that the mating ring and shaft do not come into

contact causing damage. e) Remove the O-ring [49] between the seal cover and the seal retainer [48]. f) After removing the seal cover, wipe clean and inspect the axis surface. If there are scratches, use

fine sandpaper to smooth them over. This is done to prevent damage to the internal O-ring when

pulling out the mechanical seal. g) Loosen the set screws [111] of the seal collar [109] by turning them three times.

For 1612LSC type compressors, remove the plug on the speed increaser gear casing cover and

loosen the set screws through the plug hole with a hexagonal

wrench. At this time, do not remove

the set screws, but leave them so that the tips are below the surface of the seal collar. There are

two set screws separated by 90°.

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Loosening Screws Fastened Seal Cover Seal Cover and Mating Ring

Loosening the Seal Collar Set Screw Seal Retainer

h) Pull out the seal collar part with your fingers. When pulling out, ensure that the tips of the set

screws do not hit the shaft. Axial direction damage to the shaft can cause leaks.

i) Screw two M8 eye bolts into the threaded holes in the oil seal retainer and pull out the oil seal

retainer while keeping it at a right angle against the shaft.

j) Remove the oil seal [50] that is attached into the oil seal retainer.

5.4.1.2 Inspection

a) Mechanical seal should be replaced if any defect is found during inspection. Actually, however, it is

sometimes difficult to find out defects on the sliding surface only through visual inspection. In such

circumstances, MAYEKAWA recommends to replace it with a new one in the same manner as with

O-rings or gaskets. In addition, if it is difficult to stop the compressor operation except for scheduled

inspections, we recommend to replace the mechanical seal assembly with a new one at every

inspection of this block. b) Since swelling or deformation can occur easily on O-rings, replace them each time the mechanical

seals are inspected. There are three seal O-rings: the O-ring [49] between the seal cover and seal retainer, the O-ring [103] between the mating ring and seal cover, and the O-ring [112] between the seal collar and shaft. For BOS models, there is another O-ring [106-2] on the main body of the mechanical seal, bringing the total to four O-rings.

c) Oil seal is also unconditional replace. Use genuine replacement parts. Since the oil seal is made of

a special material, only a genuine oil seal must be used for replacement.

d) Replace the seal cover gasket with a new one.

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5.4.2 Unloader Indicator

Figure 5-3 1612**C Unloader Indicator Block

T able 5-7 Unloader Indicator Components

P/N Part Name Qty Remarks P/N Part Name Qty Remarks

120 Indicator assembly 1 141 Indicator glass 1 141

121 Micro-switch base plate 1 125L** 143 Electric wiring connector 1

122

Hexagon socket head cap screw

2 M6ｘ25 144 Connector support 1 125L**

123 Micro-switch set-plate 1 125L** 145

Hexagon socket head cap screw

2 M6x15

124 Philips screw 2 M3ｘ10 146 Indicator cover (2) 1 1612LSC

125 Micro-switch 2 147A

Hexagon socket head cap screw

2 M6x95

126 Philips screw 2 M2.5ｘ25 147B 2 M6x60

127 Micro-switch cam 1 125L** 149

Micro-switch Insulation plate

1 125L**

128 Set screw 2 M4ｘ8 202 Bevel gear (2) 2 Φ6

129 Potentiometer 1 203 Indicator shaft 1

130 Potentiometer set-plate 1 200L** 204 Indicator shaft bearing 1

131 Philips screw 3 M3x5 205 Flat head screw 4 M5x14

132 Terminal block 2 LK-3P 206 Indicator glass gland 1 133 Philips screw 4 M3ｘ20 207 Indicator glass support 1

134 Potentiometer support arm 2 210 Philips screw 4 M5x15

136

Potentiometer mounting screw

4 M3ｘ14 211 Flat head screw 2 M3x5

137 Indicator dial 1

212

Hexagon socket head cap screw

4 M5x30

138 Indicator dial screw 2 M3x5 213 Spring pin 1 Φ2x8

139 Indicator needle 1 200L** 265-1 Spring washer 2 M2.5

140 Indicator needle screw 1 M3x10 265-2 Spring washer 2 M3

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5.4.2.1 Disassembly

 When removing wiring only

Remove the indicator cover before pulling out the unloader indicator wiring because the indicator has a terminal board for wiring. Perform the work as described below and after removing the wiring reattach the cover for protection.

a) Loosen the

hexagon socket head cap screws [212] holding the indicator glass. Do not

mistakenly loosen the phillips screws [210] on the same surface. Remove the indicator shaft assembly parts [141], [202 – 207], [210], and [211].

b) Remove hexagon socket head cap screws [147A] [147B] (two each) that fasten the indicator

cover [146]. Then the cover gets removable.

c) Since there is a terminal block [132], remove wiring after removing the surface plastic sheet and

loosening the screws.

Unloader Indicator Assembly Part

Removing Indicator Glass and Gland Removing Indicator Glass and Gland

Removing Indicator Shaft Assembly Removing Indicator Cover

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 When removing entire unloader indicator assembly, with the wiring left as it is

a) After the disassembly in the previous section, the internal potentiometer [129], micro-switches

[125], and micro-switch base plate [121] with micro-switch cam [127] attached can be removed.

Micro-switch base plate is fastened to the unloader cover with two hexagon socket head cap screws [122]. Since the one screw of them is hidden under the connector support [144], remove two hexagon socket head cap screws [145] and the connector support (following picture to the left).

Then remove two hexagon socket head cap screws fastening the micro-switch base plate

(above picture to the right).

d) Micro-switch cam [127] is secured to the indicator cam [77] by a set screw [128]. Turn the

micro-switch base plate to easy direction for the work, and then loosen this set screw to free the micro-switch cam (following picture to the left).

 When you remove the set screw [128] from the micro-switch cam, it is easy to

lose the screw. Leave it only to loosen.

e) Now, it is possible to remove the indicator assembly as is by pulling in the axial direction.

5.4.2.2 Inspection

Since the unloader indicator block is removed as assembly and its inspection and adjustment is often performed after reassembling and recovering the compressor, the inspection procedure is described in Section 5.7 "Reassembly" in this chapter. Refer to Section 5.5.15 "Unloader Indicator".

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Figure 5-4 Unloader Cover Block

Indicator Cam Mounting Parts

5.4.3 Unloader Cover

The unloader cover [74] contains the indicator cam [77], which converts the linear motion of the unloader slide valve to a rotational motion, and its attachment parts.

5.4.3.1 Disassembly

a) Remove the hexagon socket head cap screws [76] for

attaching the unloader cylinder cover.

b) The unloader cylinder cover can be pulled straight out as

is because the indicator cam [77] attached to the unloader cylinder cover is stuck to the inner side of the unloader push rod [67] in the unloader cylinder, and the grooved pin

(guide pin) [68] is in the groove of the indicator cam. Ensure that the unloader cylinder cover is not bent

because the axis part of the indicator cam will also become bent.

c) If the indicator cam does not move properly, check the spiral groove of the indicator cam, bearing

and guide pin. Disassembly sequence is as shown below.

c-1) The bearing gland [80] that holds the indicator

cam is secured to the cylinder side of the unloader cover. Remove the three hexagon socket head cap screws [81] that are securing the bearing gland.

c-2) Now, the indicator cam can be pulled out as it is,

together (attached to its shaft) with its ball bearing [78] and external snap ring [79] securing the bearing.

c-3) The spring retainer [84], spring [83] and V-ring

[82] are attached, in this order, to the inside of the unloader cover. The outer diameter of the Teflon V-rings is attached tightly to the holes of the unloader cover. These V-rings, once removed, cannot be reused because their tongue portion gets damaged. So be careful.

5.4.3.2 Inspection

a) Check the packing portion of the indicator cam shaft

for any flaw. If the refrigerant leaks without any flaw

observed in this part, it should be due to a defect of

the V-ring or installing the V-ring without sufficient oil.

In this case, replace the V-ring. b) Check the spiral groove of the indicator cam. If defect

such as damage or wear is found, replace it with a

new one.

V-ring

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5.4.4 Unloader Piston and Unloader Cylinder

5.4.4.1 Disassembly

a) Screw two M8 eyebolts into the unloader piston [64],

and pull out it to the no-load position (utmost front position).

b) Unbend the rotation stopper tooth of the lock washer

[70], loosen and remove the lock nut [69].

c) Now, you can remove the unloader piston.

d) The unloader cylinder [60] is attached to the

low-stage bearing head [11-1] along with the speed increaser gear casing [169] by eight long bolts [61]. Remove [61] and then pull out the unloader cylinder.

Loosening Lock Nut Removing Unloader Cylinder

5.4.4.2 Inspection

a) Remove and inspect the O-ring [65]

attached to outside the unloader piston and the cap seal [66], testing the O-ring for elasticity and deformation. Replacing the O-ring is recommended after more than two years of use.

b) Since the unloader cylinder often has

damage or oil refuse stuck to the inner surface, clean thoroughly and use fine sandpaper to smoothen it.

Removing the Cap Seal

Unbending Lock Washer Tooth

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5.4.5 Speed Increaser Gear Casing Cover

The 1612LSC model is speed increaser type compressor, so remove the speed increaser gear casing cover [171] as drive shaft cover.

5.4.5.1 Disassembly

Loosen the hexagon socket head cap screws [195]. Before removing these bolts, screw two stud bolts into the threaded holes at the top of the cover.

Although no alignment pins, the speed increaser gear casing cover does not drop by itself even when the bolts are removed because it is fitted on the thrust bearing gland located inside.

However, when you go on the disassembly work of this block without screwing the stud bolts, there is a risk to damage of the speed increaser gear spindle by dropping the cover. Make sure to screw in the stud bolts beforehand.

Tap the cover gently with a hammer to loosen the gasket which is sticking to both mating surfaces. Pull out the speed increaser gear casing cover in a direction parallel with the shaft.

Removing Speed Increaser Gear casing Cover After Cover Removal

 At this time, ensure that the speed increaser gear casing cover is supported to

avoid it toppling or dropping onto the shaft (spindle axis). Protect the shaft with a cloth beforehand.

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5.4.6 Speed Increaser Gear Casing Block

The speed increaser gear casing block needs be

disassembled when inspecting the thrust bearing block on the low-stage, pulling out the rotors, or

inspecting the speed increaser gears.

For replacing the thrust bearing [189], pilling out the speed gear increaser gear spindle [188] is required.

Figure 5-5 Speed Increaser Gear Casing

5.4.6.1 Disassembly

It is possible to separate the speed increaser gear block as an entire assembly. However, remove the side bearing for the speed increaser gear spindle before separating the speed increaser gear casing assembly.

Remove the speed increaser drive gear side bearing [183]. The side bearing is positioned by the

spring pin [184] inside the speed increaser gear casing and held by the speed increaser gear

casing cover [171]. Screw two M8 eyebolts into threaded holes on the side bearing, hang a pipe on the eyes of the

eyebolts and pull out by tapping the pipe lightly toward you (following picture to the left).

Screw M12 eyebolts into two threaded holes on the upper surface of the speed increaser gear

casing, and hook lifting tools onto the eyebolts (above picture to the right). c) Remove all the hexagon socket head cap screws [18-1]. The casing is held in position by the

alignment pins [19-1], so it remains attached to the bearing head [11-1]. d)

Tap the alignment pins [19-1] toward the bearing head [11-1].

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Screw the previously removed three bolts [18-1] into the jacking threaded holes in the flange of the

speed increaser gear casing, and screw them alternately and evenly to separate the flange from

the speed increaser gear casing (picture below).

f) After disengaging alignment pins, pull out the casing with parallel direction to the speed increaser

gear spindle shaft (following picture to the left). When there is no need to replace the speed increaser drive gear [174]

and/or speed increaser gear spindle [188] because no abnormalities are observed in them, it is not necessary to remove the speed increaser drive gear from the speed increaser gear spindle.

In such a case, start next disassembly work from removing the inner

race of roller bearing [185] described in step k) on next page.

Following steps g) to j) are the procedures for replacing the speed

increaser drive gear and/or spindle [188].

Place the speed increaser gear assembly on the work stand while facing the drive gear up, i.e. the

thrust bearing toward floor. It is acceptable to use to the work stand as shown in the above picture

to the right. However, if you can prepare the special work stand with the angle changeable surface

as shown in the following picture, you can do more safely work.

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Unbend the rotation stopper tooth of the

lock washer [270] for the lock nut [269] as

shown in the picture below, then loosen

the lock nut and remove it with the

torsional slip washer [237-D] and the lock

washer.

Then remove the speed increaser gear spacer [176] (following picture to the left).

Screw two eyebolts into threaded holes on the drive gear [174] as sown in the above picture to the

right to remove the drive gear with lifting it. k)

The inner race of roller bearing [185] which supports the spindle shaft end is attached on the shaft

end with shrink-fitting. Pull out the inner race of the roller bearing while heat up it by using a

blowtorch or the like. m) Turn upside down the speed increaser gear casing

together with the spindle, place it on the work stand

while facing the thrust bearing side to up. Since the thrust bearing [189] is firmly shrink-fitted

on the spindle to support the radial load as well as

the thrust load, there is no risk of dropping down

with the spindle during the work. n)

Remove the hexagon head bolts [191] together with

the spring washers [192] and the thrust bearing

gland [190]. The right picture is overviewed after

removing them.

Figure 5-6 Speed Increaser Drive Gear and gear spindle

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Unbend the rotation stopper tooth of the lock washer [194], loosen and pull out the lock nut [193]

with the torsional slip washer [237-C] and the lock washer. p)

As shown in the below left picture, when you tap the speed increaser gear spindle shaft end face

lightly with fitting a plastic block or the like, the spindle will fall off. Prepare a cushion to prevent the

spindle shaft from directly dropping on the floor (following picture to the right).

5.4.6.2 Inspection

a) The speed increaser gears are given extra allowance in durability to withstand hard operations and

least likely to show abnormalities under ordinary operating conditions. The gears are normal when their teeth have mirror gloss surfaces. If abnormally worn should be

found, replace them after investigating the cause and taking necessary measures. Lubrication-related components and lines should be primarily checked in this case. b)

Check the shaft seal area of the spindle shaft surface on which a mechanical seal assembly is

installed. If any flaw is observed, resurface and finish with sandpaper. c)

When you disassemble following each part, replace them with new ones, i.e. a speed increaser

drive gear side bearing [183], a roller bearing [185] including inner race and outer race, and a thrust

bearing [189].

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5.4.7 Separating High-stage and Low-stage

Separate the high-stage and low-stage when inspect the high-stage thrust bearing block or pull out each stage’s rotor is required.

Structurally, it does not matter even if separated at the first step of disassembly.

Separating High-stage and Low-stage

5.4.7.1 Disassembly

a) As explained in Section 5.3.5 of this chapter, put the compressor on a special table and remove the

bolts from the lower side. Then, remove the remaining hexagon socket head cap screws [18-2]. At this moment, the high-stage of the compressor is spaced apart the work bench. Brace the

high-stage with a rectangular piece of wood or the like to prevent it from falling when disassembled.

b) Drive alignment pins [19-2] into suction cover [5-1].

c) Since the bearing head [11-2] and suction cover are stuck together with the gasket [17], screw the

previously removed bolts [18-2] into two jacking threaded holes on the bearing head to push out the suction cover evenly. Do not insert a screwdriver or chisel into the gap.

d) On the M rotor axis there are power transmission gear couplings [151 to 161].

Move the casing in parallel with the axis to separate the driving side and the driven side in the axial direction.

Low-stage After Separation Removing Driven Hub

* Above pictures are gear coupling before the design modification of February, 2011.

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5.4.8 Gear Coupling

The gear coupling, which is used as a power transmission means, is divided into the high-stage and the low-stage blocks, with each block attached to the corresponding M rotor shaft, and these two blocks are directly connected by a drive sleeve.

Gear coupling mechanism of 1612**C models

In January 1979, the coupling method was changed from the initial type (coupling hub is directly connected using hexagon head screws) to the method using coupling hub and sleeve. This method was used for a long time.

However, the anti-falling method of the drive sleeve was modified in February 2011 as the design modification. While the old couplings have stoppers on both outer ends of the drive sleeve, the stoppers are placed on the inside of the drive sleeve after the design modification (compatible with the old type).

After this design modification, the drive sleeve stopper [154] and snap ring [155] are no more used. .

Gear coupling assembly comprising Gear coupling assembly comprising 151, 152, 153, 154*2, 155*2 and 159. 151, 152, 153 and 159.

Figure 5-7 Former Method Figure 5-8 New Method (Used Until Design Change in Feb. 2011) (Used After Design Change in Feb. 20101

5.4.8.1 Disassembly

a) Drive sleeve [151] can be removed with hands when the high-stage and low-stage are separated.

b) On the high-stage (driven) side, loosen the set screw [159] of the key [157] attached on the driven

hub [153], and then remove the driven hub. As it is clearance-fitted, it can be removed easily.

c) On the low-stage side, unbend the lock washer tooth [161] and loosen the lock nut [160] to remove

the drive hub [152].

d) Two screw holes are provided on the drive hub. Screw in M8 eye bolts, and pull out the drive hub.

As it is clearance-fitted, it can be removed easily.

For the set screw [159], MAYEKAWA recommends a knurled cup point locking screw with an anti-loosening coating on the screw.

5.4.8.2 Inspection

Check the hub and sleeve for possible deformation of the gear teeth and wear on each tooth flank. If any defect is found, replace the whole gear coupling assembly. Also, investigate cause(s) of the

defect.

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Balance Piston and Balance Piston Sleeve

5.4.9 Balance Piston Cover

Disassemble the balance piston cover when pulling out the rotors or inspecting the side bearing [28-2] or balance piston [30].

a) Loosen all hexagon socket head cap screws [24] 3 or 4 rotations, lightly tap the side of the balance

piston cover [22] with a soft hammer, and peel off the sticking balance piston cover gasket [23].

b) In this state, drain the oil from the balance piston and the side bearing block inside the suction

cover. When the oil has been drained, remove all screws apart from the one on the upper side. While holding down the balance piston cover, remove the remaining screw and remove the balance piston cover.

5.4.10 Balance Piston

When the screw compressor is operated, the thrust load on the M rotor is large and the rotation compared to the F rotor is fast. Therefore, the life of a thrust bearing on the M rotor would normally be much shorter than the life of a thrust bearing on the F rotor. To reduce the thrust bearing load on the M rotor, a hydraulic piston is installed at the end of the high-stage M rotor shaft in order to cancel the thrust load.

* A balance piston is not required on the

low-stage because, due to low-pressure conditions, the difference in life is not as big as the high-stage.

5.4.10.1 Disassembly

Change in Shape of the 1612**C Suction Cover [5-2] * It might be a too old episode.

Due to the modification in shape design of the high-stage suction cover [5-2] in February 1975, the attachment of a balance piston sleeve [33] became necessary. Accordingly, the balance piston [30] and the balance piston cover [22] were newly created.

a) Using external snap (retaining) ring pliers, remove the snap ring [32] that secures the balance

piston [30] to the rotor shaft (following picture to the left). Screw in two M8 eyebolts to remove the balance piston (following picture to the right). It is not necessary to remove the balance piston key [31] embedded in the rotor shaft.

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b) Since the 1612C model has a balance piston sleeve attached to the high-stage, remove the

hexagon socket head cap screws [34] for stopping the balance piston sleeve [33] from rotating. Make sure not to lose the attached special spring washer [335] for the hexagon socket head cap screw.

c) By using internal snap ring pliers, remove the snap ring [37] for securing the balance piston sleeve.

Since the snap ring is pushed out by the inner O-ring, it can be removed easily by pushing gently.

d) Pull out the balance piston sleeve. The sleeve can be removed easily because the gap between its

outer diameter and the suction cover is loose.

5.4.10.2 Inspection

Although there are signs of wear on the inner surface of the balance piston sleeve, this is not a problem. They result from the fact that the gap between the balance piston and the piston sleeve is smaller than the gap between the rotor shaft and the bearings.

These wears will not develop further, because a large gap is created around the outer circumference of the balance piston sleeve in order to prevent the bearing load from being applied to the balance piston.

However, you should still carefully check the condition because when the side bearing is significantly worn, the balance piston may also be worn.

Rotation Stopping Part Loosen Hexagon Socket Head Cap Screw for Balance Piston Sleeve for Rotation Stop

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5.4.11 High-stage Suction Cover and Side Bearings

If the work sequence is such that the thrust bearing block is disassembled first and then the suction cover is removed, there is a risk that, when the suction cover is separated from the main rotor casing, the rotor may also be pull out and dropped. As such, in the procedure described in this manual, the suction cover is removed first, and then the thrust bearing is disassembled.

 In this procedure to remove the suction cover before disassembling the thrust bearing

block, it is necessary to sufficiently loosen the lock nut that are securing the thrust

bearing while the rotor is supported by both the main and side bearings, in order not to

damage the rotor during the disassembly process.

5.4.11.1 Disassembly

a) Remove the hexagon head bolts [45-2] and the conical spring washers [46-2] that are used to fasten

the thrust bearing gland [43-2], and then remove the gland. In case of a former model which uses a rotation stopper fitting instead of a conical spring washer,

extend the claw bent plate of the rotation stopper and remove it from the hexagon head blot [46-2],

and then remove the hexagon head bolt and the thrust bearing gland. b) Unbend the rotation stopper tooth of the lock washer [40-2] holding the lock nut [39-2] which retains

the inner race of thrust bearing [38-2] on the rotor shaft and loosen the lock nut using a lock nut

wrench. c) As the height of the high-stage main rotor casing is low, the casing is installed like a bridge to

connect between the suction cover and the bearing head. As such, the main rotor casing will be

supported only by one side (i.e., overhang) when the suction cover is removed. To avoid this, either

place squared timbers or use a lifting device to properly support the main rotor casing. d) Loosen and remove the hexagon socket head cap screws [2-2] that hold the high-stage suction

cover [5-2] and the high-stage main rotor casing [1-2]. e) Since the suction cover gasket [6-2] is stuck to the flange surface, evenly push the suction cover by screwing two of the removed hexagon socket head cap screws [2-2] into the jacking threaded holes in the flange part of the main rotor casing. When a gap has opened, use a scraper to peel up to one direction.

f) At the position where the alignment pins can be

disengaged, remove the suction cover parallel to the axis with a single pulling motion (picture to the right).

d) The side bearing 【28-2】is press-fit from the balance

piston cover side of the suction cover. By using internal snap ring pliers, remove the snap ring [29-2] and push it out from the rotor side.

5.4.11.2 Inspection

a) Check the oil inlet path to the balance piston part of the suction cover by spraying air or the like. b)

We recommend unconditional exchange of the side bearings on the occasion of the compressor

overhaul, but for confirmation of the compressor condition and system operating condition, carefully

check the sliding part metal surface of the side bearings. If the metal surface is turned gray or any foreign matter is embedded, also carefully check the wear

of the rotor shaft. c) The inside surface of the main rotor casing should have no problems because sufficient clearance is

provided. However, if any trace of scraping by the end of the rotor is found, it should be determined

that the thrust bearing is defective. It is also necessary to check the operational condition, such as

whether the system is operated for a long time with a high intermediate pressure.

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5.4.12 Low-stage Suction Cover and Side Bearings

Similarly to the case of the high-stage, remove the low-stage suction cover before disassembling the low-stage thrust bearing block in order to prevent the rotor dropping at the time of removing the suction cover. Also in the same way of the high-stage, the lock nut fastening the thrust bearing should be loosened beforehand.

In the case of 1612LSC speed increaser type, the thrust bearing inner race on the low-stage M rotor is fastened together with the speed increaser driven gear [179] by the lock nut [39-1A]. First, pull out this driven gear to loosening the lock nut.

5.4.12.1 Disassembly

a) As shown in the following picture to the left, unbend the rotation stopper tooth of the lock washer

[40-1B], loosen the lock nut [39-1B] (following picture to the right) which is fastening the speed increaser driven gear [179]. Then, remove the lock nut, torsional slip washer [237-1B] and lock washer [40-1B].

b) As shown in the following picture to the left, pull out the speed increaser driven gear, and remove

the shaft key [180] for rotation stopper of the driven gear.

c) Remove the hexagon head bolts [45-1] that is fastening the thrust bearing gland [43-1] together

with the spring washer [46-1] (following picture to the right).

d) Remove the thrust bearing gland.

Figure 5-9 Low-stage Thrust Bearing Block

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e) And then, unbend the rotation stopper tooth of the lock washer [40-1] (following picture to the left),

loosen the lock nut [39-1] (following picture to the right).

f) Unscrew and remove four hexagon head cap screws which secured the oil injection pipe gland

[164] located in the lower area of the low-stage suction cover (following picture to the left )..

g) Screw a hexagon socket head cap screw [2-1] into the threaded hole of the oil injection pipe, and

pull out it (above picture to the right)..

h) Remove all of the hexagon socket head cap screws [2-1] tightening the main rotor casing [1-1] to

the suction cover [5-1]. Next, drive alignment pins [3-1] into the main rotor casing.

i) Screw in screws [2-1] into the two threaded holes in the rotor casing flange, and then push the

suction cover flange evenly.

j) When a gap has opened, use a scraper to peel it

up.

k) When a gap has opened to the length of the

screw, pull out the rotor axis and side bearing combination by sliding the suction cover on the work bench parallel with the axis.

m) It is possible to remove the side bearing [28-1] by

removing the internal snap ring [29-1] (picture to the right) and gently pushing the rotor side.

5.4.12.2 Inspection

Inspect the suction cover and side bearings in the same way as for the high-stage.

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5.4.13 Thrust Bearing Block

Thrust bearing (picture to the right) is a face-to-face angular contact ball bearing. This bearing only receives thrust load and does not receive the radial load perpendicular to the shaft because there is a gap between the outer ring of the thrust bearing and the bearing head. Apart from receiving the thrust load, the bearing has the important role of securing the position of the gap between the rotor and the discharge side of the bearing head. This gap (end clearance) is significantly linked with performance.

5.4.13.1 Disassembly of High-stage Thrust Bearing Block

Figure 5-10 High-stage Thrust Bearing Block

a) Remove the lock nut [39-2] that has been loosened. Then, remove the torsional slip washer [237-2],

lock washer [40-2], and thrust washer [250-2]. b) The clearance fit is applied to two gaps between the outer race of the thrust bearing and the bearing

head, between the inner race of the thrust bearing and the rotor shaft

Prepare a 1 or 2 mm diameter aluminum wire, make the tip of the wire flat by hammering, and

slightly bend the tip to make a hook. Then, insert the tip of the wire between the outer race and the

ball retainer of the thrust bearing [38-2] to hook and pull out the bearing. In this way, the bearing can

be easily removed. c) The whole thrust bearing will be removed helped by the surface tension of the oil on the side face.

If you have failed to remove the whole bearing at once, put the components in the order of the

removal. d) Attached to the inside of the thrust bearing are; thrust bearing outer race spacer [41-2] for the

bearing head-side outer ring, and the thrust bearing alignment spacer [42-2] for the rotor shaft side

inner race. To identify where to set, the thrust bearing outer race spacers and thrust bearing

alignment spacers have a stamped mark of "M" or "F" which means "for M rotor" or "for F rotor". The bearing glands, thrust washers, thrust bearings, thrust bearing outer race spacers and thrust

bearing alignment spacers, which have been removed, should be divided into two groups (M rotor

group and F rotor group). You must be very careful because if an assembly error is made to result in a wrong combination of

parts after failing to neatly arranging and separating the parts, it can lead to performance

degradation and/or dragging accident due to overheating caused by being too narrow end

clearance, for example.

P/N Part Name Qty 38-2 Thrust bearing (2) 2 39-2 Lock nut (2) 2 40-2 Lock washer (2) 2 41-2 Thrust bearing outer race spacer (2) 2 42-2 Thrust bearing alignment spacer (2) 2 43-2A Thrust bearing gland (2) A for F rotor 1 43-2B Thrust bearing gland (2) B for M rotor 1 45-2 Hexagon head screw (M8 x 30) 8 46-2 Spring washer (for M8) 8 237-2 Torsional slip washer (for 125***) 2 250-2 Thrust washer (for 125***) 2

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Pulling Out Thrust Bearing Outer race Spacer and Alignment Spacer

5.4.13.2 Disassembly of Low-stage Thrust Bearing Block

Figure 5-11 Low-stage Thrust Bearing Block

a) The roller bearing [185] outer race supporting the speed increaser dear spindle shaft end is

installed in the upper part of the low-stage bearing head (above picture). To remove this roller

bearing outer race, remove the internal snap ring [186] retaining the outer race, first (following

picture to the left).

Next remove the plugs from the two holes on the back of the bearing head. Through the holes, insert

steel rods or similar tools. Strike the rods on their ends alternately and little by little to force out the

roller bearing (following picture to the right). * The roller bearing outer race may be removed prior to the removal of the thrust bearing gland as shown in the picture to the left.

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c) Remove the lock nut [39-1] that has been loosened. Then, remove the torsional slip washer [237-1],

and lock washer [40-2], and thrust washer [250-2]. b)

At the M rotor side, remove the thrust washer [250-], thrust bearing [38-1A] and thrust bearing

alignment spacer [42-1A] in the order.

At the F rotor side, remove the thrust bearing [38-1B], thrust bearing outer race spacer [41-1] and

thrust bearing alignment spacer [42-1B] in the order.

Removing the Thrust Bearing (M rotor) Removing the Thrust Bearing (F rotor)

5.4.13.3 Inspection (High-stage/Low-stage)

a) The thrust bearing is normal if the bearing balls are found fully glossy after the thrust bearing has

been fully washed and cleaned. It is abnormal if the ball surface has tarnish streaky pattern. b) Support the inner race with your hand and rotate the outer race. If you feel abnormal vibration on the

hand, the rolling contact surface of the inner or outer race or some balls may be in an abnormal

condition. So, carefully check the conditions. You could feel some irregular click even with a small

foreign matter that has entered during the removal process. In such a case, it should return to the

normal condition when high pressure air is used to blow out the foreign matters after washing and

cleaning the unit. If the bearing is determined to be defective, it must be replaced with new ones. c) If the inner race and outer race can be easily separated, the wear is considered excessive. If so, you

cannot reuse the bearing. d) After washing the bearing, you should be able to hear a clattering sound when the bearing is rotated

by hand. Such a sound is due to the motion of the ball within the backlash or play, or the gap

between the retainer and the ball. Such a sound will not be heard if the bearing is held horizontal

and turned. If some lubricating oil is applied after washing the bearing, the sound should not be

heard when the bearing is turned. If you can still hear the sound, the bearing is abnormal. e) If any abnormality is seen in the thrust bearing in the above inspection, replace with new ones.

In addition, carefully check the reason whether due to mere aging or any problem with the operating

condition and/or lubricating mechanism. If the compressor has been operated for more than 20,000 hours without replacing the thrust

bearing, it is recommended to replace the bearing with a new one for safely continuing the operation

until the next overhaul, even if no abnormality is found in the above described inspection.

 Since a bearing is a combination of specifically designed parts, even if a bearing

with the same number is found in a bearing manufacturer's catalog, the accuracy or material may not be identical. Replace the parts with genuine parts. Parts other than genuine parts are not covered by the warranty.

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5.4.14 High-stage Rotors and Main Rotor Casing

5.4.14.1 Disassembly

a) Either the M rotor or F rotor may be removed first. However, as the M rotor is longer, it is easier to

remove the M rotor first. When pulling out the M rotor (or F rotor) first, pull out about 2/3 of the full

length of the rotor by holding the shaft upward and turning it in the CW (or CCW) direction. When approximately two thirds of the rotor has been pulled out, draw the rest out slowly while

attaching the other hand to the outer circumference of the rotor.

 You should carefully note that the rotor must be rotated in the specified direction

while pulling it out. If the M (F) rotor is not turned during the pulling out process, the F (M) rotor can also be pulled out together.

b) Do not place the removed rotor directly on the

floor. Use a cushion made of wood, etc., an I-block or a V-block to suspend the bearing part of the rotor (right picture).

c) Pull out the F rotor in the same way. Take care

not to damage the main bearing with the end of the rotor axis when removing.

5.4.14.2 Inspection

a) No abnormality should be observed on the surface of the rotor lobes under normal operations.

Regarding the contact surface of the teeth, black luster should be seen on the root area of the M

rotor lobes and on the tip area of the F rotor lobes.

In other cases, when the suction gas or oil is contaminated by fine dust, there may be fine linear

scratches on the shaft surface, in the direction perpendicular to the shaft axis. If any such flaw is

found, use a fine sand paper or grindstone to smooth the surface. b) In case of ammonia refrigerant or gas compressor, the non-contact surface of the rotor may be

discolored by rust or deposits (above picture) . Use sand papers or others to finish the surface

according to the degree of the problem. c) Then, check the bearing areas of the rotor shaft. Two types of finishing are used: one is the

induction hardening (polish finishing) for the standard specification, and the other is the hard

chrome plating (polish finishing), as a special specification. The most suitable finish is selected

according to the type of refrigerant and operation conditions.

Very little wear will be present unless the compressor is operated for a long time using dirty oil or

any hard matter is buried in the metal of the inner circumference of the bearing. d) Check the portion of the shaft on which the thrust bearing is mounted for any trace to show that the

inner race of the bearing has rotated.

If the lock nut that fastens the inner race of the thrust bearing is loosened, or if the bearing is

abnormally worn, the inner race will become rotate. If any trace of rotation is seen, correct the

problem. Depending on the degree of the rotation trace, it might be necessary to replace the rotors

with new ones. e) Check the inner surface of the main rotor casing.

There is a narrow clearance between the periphery of the rotor and the main rotor casin g. Any slight

flaw present on the tip of the rotor teeth or on the inner surface of the main rotor casing, due to small

foreign matters, will not be a problem.

If there is any trace to show that the tips of the rotor teeth have hit the inner surface of the main rotor

casing, it is an abnormal condition. In such a case, the possible cause is that the main bearing

and/or side bearing is worn out. Take proper actions by finding the cause of the problem, such as

contamination of the lubricating oil or entrance of foreign matters.

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5.4.15 Low-stage Rotors and Main Rotor Casing

Care must be taken because the low-stage rotors are heavy. In addition, since the low-stage M rotor is installed with a mechanical seal; do the work very carefully

not to damage the shaft. It is recommended to apply a protective tape on the sh aft surface. Inspect the ends of the rotor lobes and main rotor casing in the same way as the high-stage, but be

aware that there is an unloader slide valve on the low-stage which may hit against the ends of the rotor lobes. If the contact is particularly hard, scrape off the contacting parts with a scraper or file. Finally, make the surface smooth with sandpaper. After making the surface smooth, wash thoroughly with wash oil and make sure that no iron powder is left inside.

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5.4.16 High-stage Bearing Head and Main Bearings

There is a gas discharge port, based on the compressor’s operating conditions, on the surface that has the rotor of the bearing head [11-2] assembled on it.

This discharge port affects the performance of the compressor. On the bearing head there is also the main bearing which supports one end of the rotor.

5.4.16.1 Disassembly

a) Remove all hexagon socket head cap screws [2-2] that hold the casing and bearing head and hit

alignment pins into the rotor casing side.

b) Screw two hexagon head cap screws [2-2] into the

jacking threaded holes of the main rotor casing flange to

push the bearing head evenly. c)

When some gap is observed, use a scraper to remove

one side of the gasket [12-2] from the body. d) By using internal snap ring pliers, remove the snap ring

[29-2] that is retaining the main bearing. e)

The main bearing [27-2] is lightly press fit to the bearing

head.

As shown in the right picture, screw two M8 eyebolts into

threaded holes on the main bearing, and pull out it.

5.4.16.2 Inspection

a) We recommend as well as the side bearings, unconditional exchange of the main bearings on the

occasion of the compressor overhaul, but for confirmation of the compressor condition and system

operating condition, carefully check the sliding part metal surface of the main bearings. If the metal surface is gray or any foreign matter is buried, also carefully check the wear of the rotor

shaft. b) Check the condition of the surface of the bearing head on the rotor side, where the discharge port is.

Properly mend the surface if any flaw is observed. If the entire surface has significant flaws, either

the thrust bearing is defective or the end clearance adjustment is poor. If oil compression has been caused during the operation, carefully and thoroughly check the area of

the discharge port in particular. If the continued use is in doubt at all, perform the penetrant testing

(color check) to determine if it can be used or not.

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5.4.17 Low-stage Bearing Head and Main Bearings

Apart from when disassembling and inspecting the unloader slide valve, it is not necessary to separate the low-stage bearing head [11-1] and the main rotor casing [1-1].

However, according to the design modification in July 1986, of the low-stage bearing head the part where the unloader push rod is set has been changed.

Compressors manufactured before this modification need to be separated into low-stage bearing head and main rotor casing to replace O-ring [197] attached to this part.

After this modification, since the O-ring gland [326] has been added, the O-ring [197] replacement work is able to easily by removing the O-ring gland.

5.4.17.1 Disassembly

a) Remove all of the hexagon socket head cap screws [2-1].

b) Drive alignment pins [3-1] into the main

rotor casing flange side.

c) Separate the bearing head and main rotor

casing using two jacking threaded holes in the bearing head flange part.

d) Separate the embedded unloader push

rod [67] parallel to the axis.

e) Remove the internal snap ring [29-1] and

then remove the main bearing and then

pushing it from the main rotor casing side

via a pad. Otherwise, use a special tool to

pull it out as shown in the right picture.

5.4.17.2 Inspection

a) Low-stage bearing head has two lubrication holes for the speed increaser gear and the speed

increaser gear spindle. These lubrication holes are screwed in the oil flow control throttles [196-2], check that there are not clogged in the lubrication holes and throttles.

Other parts check in the same way as the high-stage.

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5.4.18 Low-stage Unloader Slide Valve and Guide Block

When the low-stage bearing head and the main rotor casing are separated, the slide valve is attached to the bottom of the main rotor casing and moves in parallel with the axis whose position is controlled by the inside guide block [87] and the outside perimeter (of the rotor casing).

The slide valve consists of slide valve 1 [54], slide valve 2 [55], hexagon socket head cap screws [58], push rod [67], and oil injection pipe guide [168] etc.

Figure 5-12 Unloader Slide Valve Assembly and Guide Block

5.4.18.1 Disassembly

a) The unloader slide valve assembly can be pulled out toward the bearing head side.

If any abnormalities are not observed, it is not necessary to disassemble the unloader slide valve

assembly.

b) The guide block stem [88] is screwed from bottom of the main rotor casing, and the guide block [87]

is engaged from the top. To replace two O-rings [89], remove the guide block stem.

5.4.18.2 Inspection

a) Inspect for abnormalities (e.g., flaw and/or wear) in the sliding surface between the unloader slide

valve and guide block. If any abnormalities observed, finish up with whetstone or the like. Also it is necessary to investigate the cause.

b) Check for defect in the guide pin [68] which mates with the indicator cam [77] of the unloader push

rod.

c) Check for looseness in the assembled state. d) With the unloader slide valve mounted in position, check a step difference from the main rotor

casing. Normally, the slide valve is positioned lower than the surface of the main rotor casing.

If the top surface of the slide valve has a trace of hitting the rotor, the probable cause is that the slide

valve is worn or the rotor shaft/bearing is worn. Please contact our local sales offices or service

centers.

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5.5 Reassembly

 When reassembling, ensure that the replaced O-rings are of the correct standard

(size, material, for secure/moving parts etc.). Incorrect replacement can lead to defects such as oil leakage.

 Some gaskets are asymmetrical. In that case, ensure that the assembly direction is

correct. If the assembly direction is not correct, a major defect could be caused by the oil route inside the casing being blocked.

After completing the disassembly and inspection procedures, start the assembly process. First, read again Section 5.1 "Precautions for Maintenance and Inspection" in this Chapter 5.

Before starting the assembly, check the replacement parts once again. Like gaskets, all O-rings that have been removed during the compressor disasse mbly must be replaced

with new ones. The reassembly sequence is mostly the reverse of the disassembly sequence. First of all, clean the

work bench and the tools to be used. Immediately prior to the assembly, use washing agent (e.g., kerosene, parts cleaner) to clean the parts

to be assembled, dry them with compressed air, and sufficiently apply lubricating oil, etc. For this, prepare a sufficient amount of clean lubricating oil for the reassembly. Also, apply oil on both sides of the gasket.

Because the assembly procedure is mostly similar between the high-stage and low-stage sides, the following sections provide explanations that are commonly used for both stages. For this purpose, the part number given in the common explanations will omit the distinction between high-stage and low-stage by means of a hyphenated suffix (the suffix of [**-1] for low-stage and [**-2] for high-stage part number will be omitted).

Please fully understand the details in this Section 5.5 for correct assembly work.

Table 5-8 Standard Tightening Torque for Hexagon Socket Head Cap Screws

T orque Unit M6 M8 M10 M12 M14 M16 M20 M24

N·m 10 25 50 90 140 240 450 750

kgf·cm 100 250 500 900 1400 2400 4500 7500

Tighten each hexagon socket head cap screw referring to the torque shown in the table above.

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Figure 5-13 Assembly Order Explanation (example)

* The circled numbers in the figure do not correspond to the steps below.

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5.5.1 Low-stage Unloader Slide Valve and Guide Block

a) First, tightly screw the guide block stem [88] into the bottom of the main rotor casing, and then

mount the guide block [87] inside the main rotor casing. b) If the slide valve assembly has been disassembled, first make sure that the alignment position

between the slide valves [54] and [55] is accurately reproduced and then tighten the hexagon

socket head cap screws [58] with spring washers [267] at the specified torque. The outer diameter

of the spring washers used here is less than normal spring washers for hexagon socket head cap

screws. So, be careful not to mix up with other washers. c)

Make sure to attach the O-ring [59] in the Oil injection pipe guide [168].

d) Gently smooth the outer surface of each part with a grindstone or sandpaper before attaching it to

the main rotor casing. Next, match the slide valve groove with the guide block and push gently.

After assembly, hold and move the unloader push rod, and inspect its movement. Also, inspect the

seam between the part and the casing to ensure that it is even. If it is not even, the part has not been assembled correctly and reassembly is necessary. Using it in that state can lead to an unforeseen accident due to the outer surface of the rotor hitting the slide valve. * : It is not a problem if the unloader slide valve is slightly lower than the casing.

 There is a problem with assembly if the unloader slide valve is higher than the

rotor casing. In that case, reassembly is essential. Using it in that state can lead to heavy damage or an accident due to the outer surface of the rotor coming into contact with the slide valve.

Guide Block Stem Inside Main Rotor Casing

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5.5.2 Bearing Head and Main Rotor Casing

 Since the bearing head gasket [12] is not formed symmetric laterally, pay

attention to the installation direction.

 If you place the bearing head gasket by just hanging it on the stud bolts, the gasket

will protrude into the inside of the rotor casing when the casing is assembled. Apply sufficient amount of oil, etc. to the gasket to make it fully attached to the surface to prevent protruding upon the assembly.

a) In case of assembling the low-stage, fit the unloader push rod [67] in the hole of bearing head [11-1].

Then, slide the bearing head or main rotor casing to let them mate together.

b) Loosely tighten the two screws, secure the alignment pin [3-1] in position, and then tighten the

screws in turn evenly. c) After tightening the screws, check that the bearing head gasket is not protruding inside the casing. d)

Also, move the slide valve back and forth to check that it works normally.

 Make sure to check for protrusion of the bearing head gasket after assembling the

bearing head and rotor casing. If this work is not performed, measurements may be incorrect due to the gasket becoming stuck between the end of the rotor and the surface of the bearing head when adjusting end clearance. Also, performance may deteriorate by operating the compressor after confirming the incorrect end clearance.

e) Since the full height of the high-stage main rotor casing is lower than that of the bearing head, both

centers will not be aligned when they are placed on the work bench. Therefore, either use a pedestal as used in the disassembly process or lift the rotor casing using a crane or other device to

align the centers. The assembly procedure after mating the both casing flanges is same as the high-sta ge. f)

As shown in the right picture, make

sure to attach the O-ring [197] and

O-ring gland [326] to the part where

the unloader push rod goes through

low-stage bearing head. However, this O-ring gland [326] is

applied after the design modification

in July 1986. For the compressors

manufactured before this change

O-ring [197] should be attached in

the groove on bearing head.

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5.5.3 Bearing Head and Main Bearings

The main bearing [27] is dimensioned in such a way that it is lightly press fit to the bearing head [11].

Position the notch of the main bearing so that it is aligned with the spring pin [14] in the bearing

head (in the case of low-stage work, using a fixture such as a guide rod is helpful as shown in the

above picture to the left), then, using a pad, lightly tap in the notch. High-stage main bearings are pushed into bearing

head using M8 eyebolts as shown in the right picture. If the position is not aligned, pull out the main bearing

and install it in again. b)

After attaching main bearings, secure them by

attaching internal snap rings (above picture to the

right). c)

Low-stage bearing head [11-1] has two lubrication

holes for the speed increaser gear and the speed

increaser gear spindle. These lubrication holes are

screwed in the oil flow control throttles [196-2],

Make sure to check that there are not clogged in

the lubrication holes and throttles. d)

Install the outer race of the roller bearing [185] for the speed increaser gear spindle [188] into the

low-stage bearing head (following picture to the left) by securing with the internal snap ring [186]

(following picture to the right). * : This assembly work may be performed as part of the reassembling procedure of the speed

increaser gear casing.

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5.5.4 Rotor Assembly

Note on the rotor profile of 1612**C

The rotor profile design was changed from A Profile to O Profile in July 1994. The biggest difference is the lobe tip edges. Profile A has the lobe tip edges while profile O does not have them

Make sufficient adjustments to the rotor. Smooth over all damage on the shaft surface of the bearing and seal using fine sandpaper.

Both the M and F rotors have unique messing positions which are indicated by engravings. When attaching to the main rotor casing, it is possible to align their positions easily by checking the

engraved numbers for the M rotor on the peak of the lobe on the discharge side and the F rotor on the peak of the lobe on the suction side.

M Rotor Assembly Mark F Rotor Assembly Mark

a) Lubricate the main bearings in the bearing head and the rotor shaft bearings sufficiently. b) While it is easier to mate the markings if the F rotor is first installed into the casing, it is not a mistake

to install the M rotor first. c) Regardless of which rotor is installed first, engage the M rotor lobe, which has engraved mark 1,

between the F rotor lobes having engraved marks 1 and 2. As factors, such as mating of lobes,

balance, etc., should be considered, be sure to mate the lobe profiles as instructed.

 Since the outer side of the rotor touches the rotor casing in this state, do not rotate

too much. Rotating may cause the rotor teeth to wear.

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5.5.5 Suction Cover and Side Bearings

a) The side bearing [28] is dimensioned in such a way that it is gentle press-fit to the suction cover [5].

Press it onto the bearing positioning pin (spring pin) [8] in the suction cover aligning it with the bearing notch. Check the alignment of the pin and notch while pressing. If they become misaligned, remove the bearing and try again. After assembly is co mplete, secure with an internal snap ring [29].

b) The suction cover gasket is asymmetrical. Check the position of the oil supply hole.

Lubricate the side bearing thoroughly.

In case of the installing work of bearings, it is helpful to use a guide rod as shown in the above picture to the left. It is able to insert the tip of the guide rod into the spring pin [8].

Since there is no flange part in the high-stage side bearing (main bearing) to fitting a guide rod, align and write a straight line on the suction cover (bearing head), also put a alignment mark to the bearing , and then push in the bearing to keep the correct position.

When press fitting, using a weight jig and a plastic spacer indicated in the Figure 5-14 makes attaching bearing works easier. The plastic spacer should be just the right size of the bearing inner diameter and hit the spacer inside with the weight jig.

Figure 5-14 Spacer and Weight Jig (example) for press fitting a Bearing

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c) When assembling the low-stage side, slide the suction cover on the work bench to move it to the

assembly location (above picture to the left). When assembling the high-st age side, use a lif ting tool shown in above picture to the right or put a stand witch adjusted height.

When fitting the side bearing and the rotor shaft, be careful not to let the end of the rotor shaft

damage the metal on the inner surface of the side bearing.

d) When the rotor shaft has entered the side bearing, push the suction cover parallel with the axis to

assemble.

e) First, screw two hexagon socket head cap screws [2] and fasten them temporarily. Then drive

alignment pins [3] into the suction cover for positioning, and tighten the fastening screws [2] evenly.

The six screws on the lower side should be tightened during final assembly on the special stand

used at disassembling.

f) Rotate the M rotor shaft with your hand and check that there is no abnormality is in meshing of the

rotors.

g) For the low-stage, attach the O-ring on the oil injection pipe [85].Then, in the same way of the

disassembly; screw a hexagon socket head cap screw [2-1] into the threaded hole on the oil injection pipe, and push the oil injection pipe into the low-stage suction cover.

h) Next, install the oil injection pipe gland [164] with attaching the O-ring [165] and fasten it with four

hexagon socket head cap screws [166].

h) Move the unloader push rod with your hand and check the smoothly movement of the unloader

slide valve. i) While holding the M rotor shaft move it in the axis direction and check that there is allowance. j) For the high-stage, assemble the balance piston and secure with an external snap ring. Check that

it is in the groove.

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5.5.6 Thrust Bearing Block

Figure 5-15 Thrust Bearing Block

T able 5-9 Configuration Parts of Thrust Bearing Block

P/N Part Name (High-stage) Q’ty

42-2 Thrust bearing alignment spacer (2) 2 41-2 Thrust bearing outer race spacer (2) 2 38-2 Thrust bearing (2) 2 sets

250-2 Thrust washer (for 125***) *High-stage only 2

40-2 Lock washer (2) 2

237-2 Torsional slip washer (2) 2

39-2 Lock nut (2) 2 43-2A Thrust bearing gland (2)A for high-stage F rotor 1 43-2B Thrust bearing gland (2)B for high-stage M rotor 1

46-2 Spring washer (2) 8

45-2 Hexagon head bolt 8

P/N Part Name (Low-stage) Q’ty

42-1A Thrust bearing alignment spacer (1)A for low-stage M rotor 1 42-1B Thrust bearing alignment spacer (1)B for low-stage F rotor 1

41-1 Thrust bearing outer race spacer (1) *Low-stage F rotor only 1 38-1A Thrust bearing (1)A for low-stage M rotor 1 set 38-1B Thrust bearing (1)B for low-stage F rotor 1 set 250-1 Thrust washer *for Low-stage M rotor only 1 40-1A Lock washer (1)A for low-stage M rotor 1 40-1B Lock washer (1)B for low-stage F rotor 1

237-1A Torsional slip washer (1)A for low-stage M rotor 1 237-1B Torsional slip washer (1)B for low-stage F rotor 1

39-1A Lock nut (1)A for low-stage M rotor 1 39-1B Lock nut (1)B for low-stage F rotor 1 43-1A Thrust bearing gland (1)A for high-stage M rotor 1 43-1B Thrust bearing gland (1)B for low-stage F rotor 1 46-1A Spring washer (1 )A for low-stage M rotor 4 46-1B Spring washer (1 )B for low-stage F rotor 4 45-1A Hexagon head bolt for low-stage M rotor 4 45-1B Hexagon head bolt for low-stage F rotor 4

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 When installing the disassembled thrust bearing as is, check the M/F engravings

on the thrust bearing outer race spacers and thrust bearing alignment spacers, and reassemble them in the same way as before disassembly. This is essential to control the end clearance of the rotor discharge side.

 Even if the same bearing is reassembled, small pieces of paint or dirt between the

spacers and washers can cause dimensions to become incorrect.

 Regarding the direction of thrust bearing assembly, there may or may not be a

V-shaped mark for assembly on the outer side of the bearing. Follow the instructions below accordingly.

a) The procedure for assembling this block is

described in Figure 5-15. The important points are explained below.

If there is a V-shaped mark for assembly on the outer side of the thrust bearing (right picture), install with the pointed end of the mark on the inner side of the machine due to a slight directional difference that affects end clearance adjustment.

If there is no V-shaped mark, assembly direction does not affect end clearance adjustment. However, to clarify the difference between the inner side and outer side of the machine, after assembling with the bearing number engravings on the outer side, make a V-shaped mark using blue whetstone on the machine’s inner side of the bearing.

b) After the thrust bearing has been installed, attach the thrust washer, lock washer, and torsional slip

washer. Then, tighten the lock nut at the specified torque or within the specified range of the tightening angle (refer to Chapter 7, Section 7.3 "Tightening Torques for Bolts and Nuts" in this manual) to secure the inner race of the thrust bearing on the rotor shaft.

After assembling the thrust bearing, rotate the M rotor shaft with your hand and check that it rotes

smoothly.

Tightening the lock nut while keeping the setting position between the lock nut wrench hooks and the lock nut grooves may cause to make the rotor run-out to enlarge due to uneven tightening forces. Change the setting position between the lock nut wrench hooks and lock nut grooves about four times when fastening the lock nut.

 Since the inner race of the thrust bearing is lodged for ease of access at the

assembly site and is secured by the tightening force of the nut alone, the tightening work is very important!

 If the thrus t bearing has been replaced, the difference between the bearing inner

race and outer race surfaces is different even if within standard values. Therefore, fully tightening the nut from the start may lead to a noticeable reduction in the life of the bearing due to a lack of end clearance between the rotor and bearing head discharge side edge, and indentations on the contact surface from ball pressure. To avoid this, check for end clearance while tightening.

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5.5.6.1 End Clearance Measurement

At this point (i.e., after the thrust bearing block has been fully assembled), measure the clearance between the bearing head end face and the rotor end face on the discharge side. This clearance is called as the end clearance. In particular, this measurement must be made when the thrust bearing has been replaced. Even if the same bearing is used, the measurement should be made for verification. If the measured clearance does not satisfy the range specified in Table 5-10, proper adjustment must be made.

Table 5-10 End Clearance (Unit: mm)

Compressor Model Rotor Profile High-stage Low-stage

1612LSC

speed increaser type

A 0.04 to 0.06

0.24 to 0.26

C 0.03 to 0.05

a) Push the rotor to the discharge side while the thrust bearing inner race is secured to the rotor shaft.

As shown in the following picture to the left, push the rotor from the suction side using a fixture (Teflon or the like). Alternatively, as shown in Figure 5-16, using the chamfered part of the lock nut, pull out the rotor with the edge of a flat screwdriver.

b) When the rotor has been pushed to the discharge side, prepare to attach the thrust bearing gland,

then attach a dial gauge on the suction side axial end of the rotor and match the indicating needle to 0 (following picture to the right).

Figure 5-16 Preparation for End Clearance Measurement

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c) Secure the bearing gland by tightening the four screws evenly to the specified tightening torque

gradually. Tightening each screw to the specified torque at once will lead to uneven tightening so tighten each screw little by little.

c) Then, read the dial gauge measurement. This value is the actual end clearance.

If the end clearance is outside the specified value, perform the adjustment work described in the next section. If the end clearance is within the specified value, turn the M rotor shaft by hand and confirm the smooth turning without uneven tightening. And then perform the measurement of the run-out of the rotor shaft described in next section (3).

Figure 5-17 End Clearance Measurement

Table 5-11 Thrust Bearing Gland Tightening Torque

Compressor Model

Tightening Torque

N·m

kgf·cm

1612LSC

speed increaser type

High-stage 30 300

Low-stage

M 50 500 F 40 400

Tightening by Bearing Gland

1. There are two types of high-stage thrust bearing gla nd. The one on the male rotor has structure which flows lubrication oil into the gear coupling.

2. The low-stage thrust bearing gland, structure is the same in M rotor side and F rotor side, size is incorrect. Hexagon head bolt to tighten also different.

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5.5.6.2 End Clearance Adjustment Method

(1) When the end clearance is smaller than the specified value

To deal with this, insert shim material (thrust adjustment liner) of required thickness (difference in thickness from the specified value) between the thrust bearing alignment spacer [42] and thrust bearing inner race.

* The thrust adjustment liner is not shown in the sectional view and development view, but available

from us. Place an order together with a model name.

Or using a highly accurate surface grinding machine or asking professional service vendors to grind, grind the surface of thrust bearing outer race spacer [41] by the difference from the specified value. After grinding the flat surface, measure the whole circumference of the saucer by using a micrometer, and check that the thickness is even.

(2) When the end clearance is larger than the specified value

As the end clearance is excessive, remove shim material (thrust adjustment liner) of a thickness equal to the difference between the measured value and the specified value if the shim material is used between thrust bearing alignment spacer and thrust bearing inner race. Or if the shim material is not used between thrust bearing alignment sp acer and thrust beari ng inne r race, or even if used but insufficient thickness, grind the surface of thrust bearing alignment spacer [42] by the difference between the measured value and the specified value or ask professional service vendors to do so. After grinding the flat surface, measure the whole circumference of the spacer by using a micrometer, and check that the thickness is even.

(3) Rotor runout measurement

When the end clearance has been a djuste d to wit hin the specified range, place a dial gauge probe

on the low-stage M rotor shaft on which a side bearing for the sp eed increaser g ear is to be inst alled. Measure the runout by turning the rotor shaft. The tolerance for runout is 0.03 mm or less for all models. Runout occurs when the thrust bearing alignment spacer and saucer are not parallel or when the thrust bearing mark is not at the correct side. And it occurs if fastening the lock nut performed without changing the position of the lock nut wrench (i.e., the uneven fastening of the lock nut). Moreover small particles of dirt trapped between parts may cause excessive runout. If the rotor runout is over the tolerance, even if the end clearance is within the specified r ange, disassemble and adjust the relative positions of the spacer, alignment spacer and thrust bearing.

5.5.6.3 Tightening after End Clearance Adjustment

a) Bend the lock washer tooth to the notch of the lock nut which is tightening the thrust bearing inner

race, to prevent rotation.

b) Remove the hexagon head bolts that are tightening thrust bearing gland [43] one by one. Insert

spring washers [46] as rotation stoppers, and tighten to the specified torque again.

After Thrust Bearing Gland Tightening Securing the Speed increaser Driven Gear

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When reassembling the low-stage compressor section of the -53, -54 and -63 models with a speed

increaser gear system, install the speed increaser driven gear [179] on the M rotor shaft by locking the gear with the key [180]. Secure the gear by fastening the lock nut with the lock washer and spacer placed in-between. Lock the lock nut by bending a tooth of the lock washer.

Figure 5-18 Speed Increaser Driven Gear

In the -52 and -62 models which are equipped with a speed increaser gear system and drive n by a 4-phase electric motor, th e speed increaser driven gear has spacers [181] on both the front and rear sides (refer to Figure 5-19).

For -53, -54 and-63 models For -52 and -63 models

Figure 5-19 Difference in Type of Speed Increaser Driven Gear

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5.5.7 Combining High-stage and Low-stage Blocks

Figure 5-20 Gear Coupling Assembly

a) On the high-stage, attach the driven hub [153] of the gear coupling, and fasten the M8 set screw

【 159] for securing the driven hub key [157]. This set screw is knurled and provided with anti-loosening.

b) On the low-stage, attach the drive hub [152], lock washer [161] and lock nut [160] in this order.

Fasten the lock nut with the specified torque or tightening angle range (see Chapter 7 "7.3

Tightening Torques for Bolts and Nuts" in this manual). Align the lock washer claw with the notch of the lock nut, and bend it. c) Set the driven sleeve onto the low-stage drive hub.

The Present Gear Coupling Parts Low-stage Gear Coupling Part

d) Screw stud bolts into two of the upper holes provided in the low-stage suction cover flange surface

which is to be attached to the high-stage. e) Apply sufficient oil to the both surfaces of the bearing cover gasket (2) [17-2]. Attach the gasket on

the flange surface over the stud bolts.

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f) Lift the high-stage by using lifting tools until it is slightly off the work bench, and move it toward the

low-stage.

At this moment, on the low-stage, slightly move the M rotor shaft in both directions, so that the gear

coupling assembly will fit smoothly (picture below).

g) After the gear coupling is engaged, press the high-stage block parallel with the rotor shaft. For both

upper and lower sides, gradually and evenly tighten, temporarily, the hexagon socket head cap

screws [18-2] that are set in the bolt holes, each hole located one or two holes apart from the left or

right alignment pin, until the high-stage and low-stage flange surfaces come into contact. h) After the flange surfaces come into contact, slightly loosen the four hexagon socket head cap

screws, which have been temporarily tightened, and then drive in the left and right alignment pins. i) Tighten the hexagon socket head cap screws to the specified torque (90 N·m). The lower bolts

should be tightened on the special

stand, which was used during disassembly.

j) Turn the low-stage M rotor (use of a jig for rotating the rotor is helpful), and check that it rotates

properly.

5.5.8 Balance Piston Cover

Attach the balance piston cover gasket [23] on the high-stage suction cover flange while paying attention to the oil hole of the gasket. It is no problem which assembly work is fast, attaching balance piston cover to main rotor casing or combining low-stage and high stage blocks.

Attaching Balance Piston Cover

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