YASKAWA SGM, SGMP, SGDA User Guide
USER'S MANUAL
AC Servomotors and Drivers
SGM/SGMP Servomotors
SGDA Servopack
YASKAWA
YA S K A WA
MANUAL NO. TSE-S800-15C
PREFACE
The rapid progress being made in today’s automation and information
technologies is resulting in a growing need for even more-advanced motion
control for future high-tech equipment. The end result is a need for devices
that can provide more-precise and quicker motion at higher speeds. Servo
control technology makes this possible. Launched by Yaskawa in 1993, the
Σ Series consists of innovative AC Servos that were developed using
leading-edge servo control technology.
This manual covers all products in the Σ Series, which feature superior
functions and performance. This manual was designed to provide
comprehensible information for users who are about to use a servo for the
first time as well as for users who already have experience in using servos.
This manual enables users to understand what Σ-Series AC Servos are all
about and how to design, install, operate, and maintain a servo system.
Keep this manual in a convenient location and refer to it whenever
necessary in operating and maintaining the servo system.
YASKAWA ELECTRIC CORPORATION
General Precautions
S Some drawings inthis manual are shown with the protective cover or shields removed, in order to
describe the detail with more clarity. Make sure all covers and shields are replaced before operating this product.
S Some drawings in this manual are shown as typical example and may differ from the shipped
product.
S This manual may be modified when necessary because of improvement of the product, modifica-
tion or changes in specifications.
Such modification is made as a revision by renewing the manual No.
S To order a copy of this manual, if your copy has been damaged or lost, contact your YASKAWA
representative listed on the last page stating the manual No. on the front cover.
S YASKAWA is not responsible for accidents or damages due to any modification of the product
made by the user since that will void our guarantee.
NOTES FOR SAFE OPERATION
Read this manual thoroughly before installation, operation, maintenance or inspection of the AC Servo
Drives. In this manual, the NOTES FOR SAFE OPERATION are classified as “WARNING” or
“CAUTION”.
WARNING
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious personal inju-
ry.
CAUTION
Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate personal
injury and/or damage to the equipment.
In some instances, items described in
follow these important items.
CAUTION
may also result in a serious accident. In either case,
iv
WARNING
(WIRING)
S Grounding must be in accordance with the national code and consistent
with sound local practices.
Failure to observe this warning may lead to electric shock or fire.
(OPERATION)
S Never touch any rotating motor parts during operation.
Failure to observe this warning may result in personal injury.
(INSPECTION AND MAINTENANCE)
S Be sure to turn OFF power before inspection or maintenance.
Otherwise, electric shock may result.
S Never open the terminal cover while power is ON, and never turn ON pow-
er when the terminal cover is open.
Otherwise, electric shock may result.
S After turning OFF power, wait at least five minutes before servicing the
product.
Otherwise, residual electric charges may result in electric shock.
CAUTION
(RECEIVING)
S Use the specified combination of SERVOMOTOR and SERVOPACK.
Failure to observe this caution may lead to fire or failure.
(INSTALLATION)
S Never use the equipment where it may be exposed to splashes of water,
corrosive or flammable gases, or near flammable materials.
Failure to observe this caution may lead to electric shock or fire.
(WIRING)
S Do not connect t hree−phase power supply t o output terminals
W
.
Failure to observe this caution may lead to personal injury or fire.
S Securely tighten screws on the power supply and motor output terminals.
Failure to observe this caution can result in a fire.
UV
and
v
CAUTION
(OPERATION)
S To avoid inadvertent accidents, run the SERVOMOTOR only in test run
(without load).
Failure to observe this caution may result in personal injury.
S Before starting operation with a load connected, set up user constants
suitable for the machine.
Starting operation without setting up user constants may lead to overrun failure.
S Before starting operation with a load connected, make sure emergency-
stop procedures are in place.
Failure to observe this caution may result in personal injury.
S During operation, do not touch the heat sink.
Failure to observe this caution may result in burns.
(INSPECTION AND MAINTENANCE)
S Do not disassemble the SERVOMOTOR.
Failure to observe this caution may result in electric shock or personal injury.
S Never change wiring while power is ON.
Failure to observe this caution may result in electric shock or personal injury.
vi
Manual Contents
This manual provides Σ-Series users with information on the following:
• An overview of servo systems for first-time users.
• Checking the product on delivery and basic applications of the servo.
• Servo applications.
• Selecting an appropriate servo for your needs and placing an order.
• Inspection and maintenance.
Manual Structure
All chapters in this manual are classified into one or more of three areas according to their contents: A, B, and
C. Refer to the applicable chapters for the information you require.
A: Chapters explaining how to select a servo: For users who wish to gain a basic understanding of
Σ Series products or who need to select an appropriate servo.
B: Chapters explaining how to design a servo system: For users who are about to design, install, and
operate a Σ-Series Servo Control System.
C: Chapters explaining maintenance: For users who are going to maintain and troubleshoot Σ-Series
products.
Chapter
CHAPTER 1 For First-time Users of AC Servos 1 A, B....................... .........
CHAPTER 2 Basic Uses of Σ-series Products 15 B........................ .........
CHAPTER 3 Applications of Σ-series Products 51 B....................... .........
CHAPTER 4 Using the Digital Operator 167 B.............................. ........
CHAPTER 5 Servo Selection and Data Sheets 205 A, B........................ ........
CHAPTER 6 Inspection, Maintenance, and Troubleshooting 343 C........... ........
APPENDIXES
Title Page Area
Provides an overview of servos and the Σ Series.
Describes steps to take when product is received, plus basic
wiring and application methods.
Describes the effective usage of Σ-Series features according to
application.
Describes operating procedures for Σ-Series servos, turning
features ON and OFF, setting control constants, etc.
Describes selection methods for Σ-Series servos and peripherals and provides servo specifications.
Describes user maintenance and troubleshooting.
A Differences between SGDA and SGD Servopacks 367 A, B. C........... ........
B Servo Adjustment 374 B, C....................................... ........
C List of I/O Signals 365 A, B, C....................................... ........
D List of User Constants 397 B, C................................... ........
E List of Alarm Displays 409 B, C.................................... ........
INDEX
415 A, B, C.............................................................. ........
vii
Basic Terms
Unless otherwise specified, the following definitions are used:
Servomotor: Σ-Series SGM/SGMP Servomotor
Servopack: An amplifier (Trademark of Yaskawa servo amplifier “SGDA Servopack”)
Servodrive: A SGM/SGMP Servomotor and an amplifier (SGDA Servopack)
Servo system: A complete servo control system consisting of servodrive, host controller,
Visual Aids
The following aids are used to indicate certain types of information for easier reference.
.
and peripheral devices
Indicates references for additional information.
TERMS
SGDA- S
Speed/Torque
SGDA- P
Positions
JUSP-OP02A-1
Technical terms placed in bold in the text are briefly explained in a “TERMS” section at the bottom of the page. The following kinds of technical terms are explained:
Technical terms that need to be explained to users who are not very familiar with
servo systems or electronic devices and technical terms specific to Σ Series Ser-
vos that need to be explained in descriptions of functions.
The text indicated by this icon is applicable only to Servopacks for speed/torque
control (Type: SGDAIf neither this icon nor the following icon appears, the description is applicable to
both types of Servopack.
The text indicated by this icon is applicable only to Servopacks for position control
(Type: SGDA-
If neither this icon nor the previous icon appears, the description is applicable to
both types of Servopack.
The text indicated by this icon explains the operating procedure using hand-held
type digital operator (Type: JUSP-OP02A-1).
The text indicated by this icon explains the operating procedure using mount type
digital operator (Type: JUSP-OP03A).
jjj
P).
jjj
S).
viii
JUSP-OP03A
NOTE A Σ-Series Servodrive alone cannot ensure the functionality and performance of the entire
machine control system. It must be combined with an appropriate machine and host controller so that the entire control system works properly. Therefore, carefully read the instruction
manuals for the machine to be used before attempting to operate the servodrive.
Yaskawa, 1995
All rights reserved. No part of thispublication may be reproduced, stored in aretrieval system, or transmitted, in any form, or
by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permission of Yaskawa. No patent liability is assumed with respect to the use of the information contained herein. Moreover,because Yaskawa
is constantly striving to improve its high-quality products, the information contained in this manual is subject to change
without notice. Every precaution has been taken in the preparation of this manual. Nevertheless, Yaskawa assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information
contained in this publication.
ix
CONTENTS
CHAPTER 1 FOR FIRST-TIME USERS OF AC SERVOS 1...............
1.1 Basic Understanding of AC Servos 2..........................................
1.1.1 Servo Mechanisms 2................................................
1.1.2 Servo Configuration 5...............................................
1.1.3 Features of Σ-Series Servos 11.........................................
CHAPTER 2 BASIC USES OF Σ-SERIES PRODUCTS 15.................
2.1 Precautions 16.............................................................
2.1.1 Notes on Use 16....................................................
2.2 Installation 18.............................................................
2.2.1 Checking on Delivery 18..............................................
2.2.2 Installing the Servomotor 19...........................................
2.2.3 Installing the Servopack 22............................................
2.3 Connection and Wiring 25....................................................
2.3.1 Connecting to Peripheral Devices 25....................................
2.3.2 Main Circuit Wiring and Power ON Sequence 2 8..........................
2.3.3 Examples of Connecting I/O Signal Terminals 30..........................
2.4 Conducting a Test Run 37....................................................
2.4.1 Test Run in Two Steps 37.............................................
2.4.2 Step 1: Conducting a Test Run for Motor without Load 39...................
2.4.3 Step 2: Conducting a Test Run with the Motor Connected to the Machine 44.....
2.4.4 Supplementary Information on Test Run 46...............................
2.4.5 Minimum User Constants Required and Input Signals 48....................
CHAPTER 3 APPLICATIONS OF Σ-SERIES PRODUCTS 51..............
3.1 Setting User Constants According to Machine Characteristics 54.....................
3.1.1 Changing the Direction of Motor Rotation 54.............................
3.1.2 Setting the Overtravel Limit Function 56.................................
3.1.3 Restricting Torque 59................................................
3.2 Setting User Constants According to Host Controller 65............................
3.2.1 Inputting Speed Reference 65..........................................
3.2.2 Inputting Position Reference 69........................................
3.2.3 Using Encoder Output 73.............................................
3.2.4 Using Contact I/O Signals 77..........................................
3.2.5 Using Electronic Gear 79.............................................
3.2.6 Using Contact Input Speed Control 83...................................
3.2.7 Using Torque Control 88..............................................
3.2.8 Using Torque Feed-forward Function 94.................................
3.2.9 Using Torque Restriction by Analog Voltage Reference 95...................
3.2.10 Using the Reference Pulse Inhibit Function (INHIBIT) 97...................
3.2.11 Using the Reference Pulse Input Filter Selection Function 99.................
3.3 Setting Up the Σ Servopack 100................................................
3.3.1 Setting User Constants 100.............................................
3.3.2 Setting the Jog Speed 101..............................................
3.3.3 Setting the Number of Encoder Pulses 102.................................
3.3.4 Setting the Motor Type 103.............................................
x
CONTENTS
3.4 Setting Stop Mode 104.......................................................
3.4.1 Adjusting Offset 104..................................................
3.4.2 Using Dynamic Brake 105.............................................
3.4.3 Using Zero-Clamp 106................................................
3.4.4 Using Holding Brake 107..............................................
3.5 Running the Motor Smoothly 111...............................................
3.5.1 Using the Soft Start Function 111........................................
3.5.2 Using the Smoothing Function 112.......................................
3.5.3 Adjusting Gain 112...................................................
3.5.4 Adjusting Offset 113..................................................
3.5.5 Setting the Torque Reference Filter Time Constant 113.......................
3.6 Minimizing Positioning Time 114...............................................
3.6.1 Using Autotuning Function 114.........................................
3.6.2 Setting Servo Gain 114................................................
3.6.3 Using Feed-forward Control 116........................................
3.6.4 Using Proportional Control 116.........................................
3.6.5 Setting Speed Bias 117................................................
3.6.6 Using Mode Switch 118...............................................
3.6.7 Using Speed Loop Compensation Function 124.............................
3.7 Forming a Protective Sequence 125.............................................
3.7.1 Using Servo Alarm Output and Alarm Code Output 125......................
3.7.2 Using Servo ON Input Signal 125........................................
3.7.3 Using Positioning Complete Signal 129...................................
3.7.4 Using Speed Coincidence Output Signal 131...............................
3.7.5 Using Running Output Signal 132.......................................
3.7.6 Handling of Power Loss 134............................................
3.8 Special Wiring 136..........................................................
3.8.1 Wiring Instructions 136................................................
3.8.2 Wiring for Noise Control 138...........................................
3.8.3 Using More Than One Servo Drive 143...................................
3.8.4 Using Regenerative Units 144...........................................
3.8.5 Using an Absolute Encoder 148.........................................
3.8.6 Extending an Encoder Cable 157........................................
3.8.7 Using SGDA Servopack with High Voltage Line 159........................
3.8.8 Connector Terminal Layouts 161........................................
CHAPTER 4 USING THE DIGITAL OPERATOR 167.....................
4.1 Basic Operations 168.........................................................
4.1.1 Connecting the Digital Operator 168.....................................
4.1.2 Resetting Servo Alarms 169............................................
4.1.3 Basic Functions and Mode Selection 170..................................
4.1.4 Operation in Status Display Mode 171....................................
4.1.5 Operation in User Constant Setting Mode 174..............................
4.1.6 Operation in Monitor Mode 179.........................................
xi
CONTENTS
4.2 Using the Functions 183......................................................
4.2.1 Operation in Alarm Trace-back Mode 183.................................
4.2.2 Operation Using the Digital Operator 186.................................
4.2.3 Autotuning 189......................................................
4.2.4 Reference Offset Automatic Adjustment 196...............................
4.2.5 Speed Reference Offset Manual Adjustment Mode 174.......................
4.2.6 Clearing Alarm Trace-back Data 202.....................................
4.2.7 Checking Motor Type 203..............................................
4.2.8 Checking Software Version 204.........................................
CHAPTER 5 SERVO SELECTION AND DATA SHEETS 205...............
5.1 Selecting a Σ-Series Servo 207.................................................
5.1.1 Selecting a Servomotor 207............................................
5.1.2 Selecting a Servopack 213.............................................
5.1.3 Selecting a Digital Operator 215.........................................
5.2 SGM Servomotor 217........................................................
5.2.1 Ratings and Specifications 217..........................................
5.2.2 Mechanical Characteristics 232..........................................
5.3 Servopack Ratings and Specifications 235........................................
5.3.1 Ratings and Specifications 235..........................................
5.3.2 Overload Characteristics 240...........................................
5.3.3 Starting Time and Stopping Time 241.....................................
5.3.4 Load Inertia 241.....................................................
5.3.5 Overhanging Loads 244...............................................
5.3.6 In-rush Current and Power Loss 245......................................
5.4 Σ-Series Dimensional Drawings 246.............................................
5.4.1 Servomotor Dimensional Drawings 246...................................
5.4.2 Servopack Dimensional Drawings 289....................................
5.4.3 Digital Operator Dimensional Drawings 291...............................
5.5 Selecting Peripheral Devices 293...............................................
5.5.1 Selecting Peripheral Devices 293........................................
5.5.2 Order List 299.......................................................
5.6 Specifications and Dimensional Drawings of Peripheral Devices 308...................
5.6.1 Cable Specifications and Peripheral Devices 308............................
5.6.2 Motor Cables 311....................................................
5.6.3 Connector Kits 314...................................................
5.6.4 Brake Power Supply 318...............................................
5.6.5 Encoder Cables 320...................................................
5.6.6 Battery for Absolute Encoder 325........................................
5.6.7 1CN Connector 326...................................................
5.6.8 Connector Terminal Block Converter Unit 328.............................
5.6.9 Cable With 1CN Connector and One End Without Connector 330..............
5.6.10 Circuit Breaker 330...................................................
5.6.11 Noise Filter 331......................................................
5.6.12 Magnetic Contactor 332...............................................
5.6.13 Surge Suppressor 333.................................................
5.6.14 Regenerative Unit 334.................................................
xii
CONTENTS
5.6.15 Variable Resistor for Speed Setting 335...................................
5.6.16 Encoder Signal Converter Unit 336......................................
5.6.17 Cables for Connecting PC and Servopack 338..............................
CHAPTER 6 INSPECTION, MAINTENANCE, AND TROUBLESHOOTING 343
6.1 Inspection and Maintenance 344................................................
6.1.1 Servomotor 344......................................................
6.1.2 Servopack 345.......................................................
6.1.3 Replacing Battery for Absolute Encoder 346...............................
6.2 Troubleshooting 347.........................................................
6.2.1 Troubleshooting Problems with Alarm Display 347..........................
6.2.2 Troubleshooting Problems With No Alarm Display 366......................
6.2.3 Internal Connection Diagram and Instrument Connection Examples 368.........
APPENDIXES
A Differences Between SGDA and SGD Servopacks 367..............................
B Servo Adjustment 374........................................................
B.1 Σ-Series AC Servopack Gain Adjustment 374.....................................
B.1.1 Σ-Series AC Servopacks and Gain Adjustment Methods 374..................
B.1.2 Basic Rules for Gain Adjustment 375.....................................
B.2 Adjusting a Speed-control Servopack 376........................................
B.2.1 Adjusting Using Auto-tuning 376........................................
B.2.2 Manual Adjustment 377...............................................
B.3 Adjusting a Position-control Servopack 380.......................................
B.3.1 Adjusting Using Auto-tuning 380........................................
B.3.2 Manual Adjustment 381...............................................
B.4 Gain Setting References 385...................................................
B.4.1 Guidelines for Gain Settings According to Load Inertia Ratio 385..............
C List of I/O Signals 385........................................................
D List of User Constants 397....................................................
E List of Alarm Displays 409....................................................
INDEX 415...........................................................
xiii
FOR FIRST-TIME USERS OF AC SERVOS
1
1
This chapter is intended for first-time users of AC servos. It describes the basic configuration of a servo mechanism and basic technical terms relating to
servos.
Users who already have experience in using a servo should also take a look at
this chapter to understand the features of Σ-Series AC Servos.
1.1 Basic Understanding of AC Servos 2...........
1.1.1 Servo Mechanisms 2..................................
1.1.2 Servo Configuration 5.................................
1.1.3 Features of Σ-Series Servos 11...........................
1
1
FOR FIRST−TIME USERS OF AC SERVOS
1.1.1 Servo Mechanisms
1.1 Basic Understanding of AC Servos
This section describes the basic configuration of a servo mechanism and technical terms
relating to servos and also explains the features of Σ-Series AC Servos.
1.1.1 Servo Mechanisms 2..............................................
1.1.2 Servo Configuration 5..............................................
1.1.3 Features of Σ-Series Servos 11......................................
1.1.1 Servo Mechanisms
You may be familiar with the following terms:
• Servo
• Servo mechanism
• Servo control system
In fact, these terms are synonymous. They have the following meaning:
A control mechanism that monitors physical quantities such as specified positions.
In short, a servo mechanism is like a servant who does tasks faithfully and quickly according
to his master’s instructions. In fact, “servo” originally derives from the word “servant.”
TERMS
Servo mechanism
According to Japanese Industrial Standard (JIS) terminology, a “servo mechanism” is defined as a mechanism that uses the position, direction, or orientation of an object as a process variable to control a system to follow any changes in a target value (set point).
More simply, a servo mechanism is a control mechanism that monitors physical quantities
such as specified positions. Feedback control is normally performed by a servo mechanism. (Source: JIS B0181)
2
1.1 Basic Understanding of AC Servos
Servo system could be defined in more detail as a mechanism that:
• Moves at a specified speed and
• Locates an object in a specified position
To develop such a servo system, an automatic control system involving feedback control
must be designed. This automatic control system can be illustrated in the following block diagram:
Configuration of Servo System
Specified position
input
Servo
amplifier
Servo
motor
Feedback part
Detector
Controlled
machine
(load)
Machine position
output
This servo system is an automatic control system that detects the machine position (output
data), feeds back the data to the input side, compares it with the specified position (input
data), and moves the machine by the difference between the compared data.
In other words, the servo system is a control system that forces the output data to
match the specified input data.
If, for example, the specified position changes, the servo system will reflect the changes.
In the above example, input data is defined as a position, but input data can be any physical
quantities such as orientation (angle), water pressure, or voltage.
1
TERMS
Position, speed, force (torque), electric current, and so on are typical controlled values for a
servo system.
The main technical terms used in this manual are as follows:
1) Servo mechanism
2) Servo
Normally, servo is synonymous with servo mechanism. However, because “mechanism” is
omitted, the meaning becomes somewhat ambiguous. Servo may refer to the entire servo
mechanism but may also refer to an integral part of a servo mechanism such as a servomotor
or a servo amplifier. This manual also follows this convention in the use of the term “servo”.
Feedback control
A control that returns process variables to the input side and forms a closed loop. It is also
called closed-loop control.
3
1
FOR FIRST−TIME USERS OF AC SERVOS
1.1.1 Servo Mechanisms
cont.
3) Servo control system
Servo control system is almost synonymous with servo mechanism but places the focus on
system control. In this manual, the term “servo system” is also used as a synonym of servo
control system.
Related Terms Meaning
Servomotor General servomotors or Yaskawa SGM/SGMP
Servopack Trademark of Yaskawa servo amplifier “SGDA Servopack.”
Servo drive A Servomotor and amplifier pair. Also called “servo.”
Servo system A closed control system consisting of a host controller,
Servomotors. In some cases, a position detector (encoder)
is included in a servomotor.
Servopack is divided into two types: SGDA-jjjS (for
speed/torque control) and SGDA-jjjP (for position
control).
servo drive and controlled system to form a servo
mechanism.
Host controller
Reference
Amplifier
(Servopack)
Servo drive
Servomotor
Servo system
Operate
Controlled
system
4
1.1.2 Servo Configuration
1) Configuration of Servo System
The following diagram illustrates a servo system in detail:
1.1 Basic Understanding of AC Servos
Host controller
(5)
Position or
speed
reference
Servo amplifier
Comparator
(Input)
Position or
speed
feedback
Power
amplifier
Detector
(1) Controlled system: Mechanical system for which the position or speed is to be con-
trolled.
This includes a drive system that transmits torque from a servomotor.
(4)
Motor
drive
circuit
Gear
(2)
(3)
Servomotor Drive system
(Output)
(1)
Controlled
system
Position
Speed
Movable
table
Ball screw
1
(2) Servomotor: A main actuator that moves a controlled system. Two types are
available: AC servomotor and DC servomotor.
(3) Detector: A position or speed detector. Normally, an encoder mounted on
a motor is used as a position detector.
(4) Servo amplifier: An amplifier that processes an error signal to correct the differ-
ence between a reference and feedback data and operates the
servomotor accordingly. A servo amplifier consists of a
comparator, which processes error signals, and a power amplifier, which operates the servomotor.
(5) Host controller: A device that controls a servo amplifier by specifying a position
or speed as a set point.
5
FOR FIRST−TIME USERS OF AC SERVOS
1.1.2 Servo Configuration
cont.
Servo components (1) to (5) are outlined below:
(1) Controlled system
In the previous figure, the controlled system is a movable table for which the position
or speed is controlled. The movable table is driven by a ball screw and is connected to
the servomotor via gears.
So, the drive system consists of:
1
Gears + Ball Screw
This drive system is most commonly used because the power transmission ratio
(gear ratio) can be freely set to ensure high positioning accuracy. However, play in the
gears must be minimized.
The following drive system is also possible when the controlled system is a movable
table:
Coupling + Ball Screw
When the power transmission ratio is 1 :
1, a coupling is useful because it has no
play.
Coupling
Rolling-contact
guide
Ball screw
Rolling-contact
bearing
This drive system is widely used for machining tools.
Housing
Timing Belt + Trapezoidal Screw Thread
A timing belt is a coupling device that allows
the power transmission ratio to be set freely
and that has no play.
A trapezoidal screw thread does not provide
excellent positioning accuracy, so can be
Trapezoidal
screw
thread
treated as a minor coupling device.
Servomotor
Timing belt
To develop an excellent servo system, it is important to select a rigid drive system that
has no play.
Configure the controlled system by using an appropriate drive system for the control
purpose.
TERMS
Drive system
Also called a drive mechanism.
A drive system connects an actuator (such as a servomotor) to a controlled system and
serves as a mechanical control component that transmits torque to the controlled system,
orientates the controlled system, and converts motion from rotation to linear motion and
vice versa.
6
(2) Servomotor
(a) DC Servomotor and AC Servomotor
Servomotors are divided into two types: DC servomotors and AC servomotors.
DC servomotors are driven by direct current (DC). They have a long history. Up
until the 1980s, the term “servomotor” used to imply a DC servomotor.
1.1 Basic Understanding of AC Servos
From 1984, AC servomotors were emerging as a result of rapid progress in microprocessor technology. Driven by alternating current (AC), AC servomotors are
now widely used because of the following advantages:
• Easy maintenance: No brush
• High speed: No limitation in rectification rate
Note however that servomotors and Servopacks use some parts that are subject
to mechanical wear or aging. For preventive maintenance, inspect and replace
parts at regular intervals.
For details, refer to Chapter 6 Inspection, Maintenance, and Troubleshooting.
(b) AC Servomotor
AC servomotors are divided into two types: synchronous type and induction type.
The synchronous type is more commonly used.
For a synchronous type servomotor, motor speed is controlled by changing the
frequency of alternating current.
A synchronous type servomotor provides strong holding torque when stopped, so
this type is ideal when precise positioning is required. Use this type for a servo
mechanism for position control.
1
The following figure illustrates the structure of a synchronous type servomotor:
Rotary disc
Light-emitting
element
Position detector
(encoder)
Light-receiving
element
Armature
wire
Lead wire
Housing
Stator core
Magnet
Front cap
Ball bearing
Shaft
Rotor core
Yaskawa SGM and SGMP Servomotors are of the synchronous type.
7
FOR FIRST−TIME USERS OF AC SERVOS
1.1.2 Servo Configuration
cont.
(c) Performance of Servomotor
A servomotor must have “instantaneous power” so that it can start as soon as a
start reference is received.
The term “power rating (kW/s)” is used to represent instantaneous power.
It refers to the electric power (kW) that a servomotor generates per second.
The greater the power rating, the more powerful the servomotor.
1
(3) Detector
A servo system requires a position or speed detector. It uses an encoder mounted on
a servomotor for this purpose.
Encoders are divided into the following two types:
(a) Incremental Encoder
An incremental encoder is a pulse generator, which generates a certain number
of pulses per revolution (e.g., 2,000 pulses per revolution). If this encoder is connected to the mechanical system and one pulse is defined as a certain length
(e.g., 0.001 mm), it can be used as a position detector.
However,this encoder does not detect an absolute position and merely outputs a
pulse train. Hence zero return operation must be performed before positioning.
The following figure illustrates the operation principle of a pulse generator:
Phase A pulse train
Phase B pulse train
Fixed slit
Light-receiving
element
Rotary slit
Center of
revolution
Phase A
Phase B
Phase Z
Rotary
disc
Slit
Light-emitting
element
(b) Absolute Encoder
An absolute encoder is designed to detect an absolute angle of rotation as well as
to perform the general functions of an incremental encoder. With an absolute encoder,therefore, it is possible to create a system that does not require zero return
operation at the beginning of each operation.
• Difference between an absolute
An absolute
encoder will keep track of the motor shaft position even if system
and incremental encoder:
power is lost and some motion occurs during that period of time. The incremental
encoder is incapable of the above.
8
1.1 Basic Understanding of AC Servos
(4) Servo amplifier
A servo amplifier is required to operate an AC servomotor.
The following figure illustrates the configuration of a servo amplifier:
Servo amplifier
Motor driving AC power
Servomotor
Commercial AC power
Reference
input
Comparator
Feedback
Power
amplifier
A servo amplifier consists of the following two sections:
(a) Comparator
A comparator consists of a comparison function and a control function. The comparison function compares reference input (position or speed) with a feedback
signal and generates a differential signal.
1
TERMS
The control function amplifies and transforms the differential signal. In other
words, it performs proportional (P) control or proportional/integral (PI) control.
(It is not important if you do not understand these control terms completely at this
point.)
(b) Power Amplifier
A power amplifier runs the servomotor at a speed or torque proportional to the
output of the comparator. In other words, from the commercial power supply of
50/60 Hz, it generates alternating current with a frequency proportional to the reference speed and runs the servomotor with this current.
Proportional/integral (PI) control
PI control provides more accurate position or speed control than proportional control, which
is more commonly used.
9
1
FOR FIRST−TIME USERS OF AC SERVOS
1.1.2 Servo Configuration
cont.
(5) Host Controller
A host controller controls a servo amplifier by specifying a position or speed as a set
point.
For speed reference, a position control loop may be formed in the host controller when
a position feedback signal is received. Yaskawa PROGIC-8 is a typical host controller.
10
TERMS
PROGIC-8
A programmable machine controller. If combined with a
servo amplifier for speed control (maximum eight axis
control), the PROGIC-8 can provide position control.
The PROGIC-8 also provides programmable controller
functions.
1.1.3 Features of Σ-Series Servos
1) Σ-Series SGM/SGMP Servomotors are synchronous type servomotors and have the following features:
• Size and weight reduced to one-third those of
our conventional models.
Compact Servomotor for saving installation
space.
• Servo performance (power rating) enhanced to
three times that of our conventional models.
Enhanced power rating (kW/s) to satisfy every
need.
• A wide product range covering rated output of
30 W to 750 W.
1.1 Basic Understanding of AC Servos
1
SGM type
Supply Voltage Rated Output
100 VAC: 30 W, 50 W, 100 W, 200 W, 300 W
(0.04 HP, 0.07 HP, 0.13 HP, 0.27 HP, 0.40 HP)
200 VAC: 30 W, 50 W, 100 W, 200 W, 400 W, 750 W
(0.04 HP, 0.07 HP, 0.13 HP, 0.27 HP, 0.53 HP, 1.01 HP)
2) SGDA Servopacks are divided into the following
two types according to usage:
• For Speed/Torque Control: SGDA-jjjS Type
This type uses speed or torque reference input.
Reference input is by analog voltage.
• For Position Control: SGDA-jjjP Type
This type uses position reference input. Reference
input is by pulse train.
SGMP type
TERMS
Power rating (kW/s)
A constant that represents response performance of a servomotor. It can be determined by
dividing squared rated torque by motor inertia. Power rating is the electric power (kW) that a
servomotor can generate per second.
The greater the power rating, the more powerful the servomotor.
11
1
FOR FIRST−TIME USERS OF AC SERVOS
1.1.3 Features of Σ-Series Servos cont.
3) The most common usage of a Servopack for speed/torque control is shown below:
• Using Servopack for Speed/Torque Control (Speed Control)
Position reference +
Position
feedback
(Analog
voltage)
Speed
reference
Position
Host controller
Position control loop
Servopack for
speed/torque control
Speed
Convert
Pulse train
Position feedback
Power
amplifier
Servomotor
Torque
(current)
feedback
Encoder
As shown in the figure above, a position control loop is formed in the host controller. The
host controller compares a position reference with a position feedback signal and sends
processing results to the Servopack as a speed reference.
In this way, the host controller can freely perform the control required for the servo mechanism.
The Servopack undertakes the speed control loop and subsequent control processing.
Yaskawa programmable machine controller PROGIC-8 is available as a typical host controller.
12
1.1 Basic Understanding of AC Servos
4) Servopack for speed/torque control can also provide torque control as shown below.
• Using Servopack for Speed/Torque Control (Torque Control)
Host controller
Position
monitoring
Position
information
Speed
reference
Torque
reference
(Analog
voltage)
(Analog voltage)
Position
Convert
Position feedback Encoder
Servopack for
speed/torque
control
Speed
Pulse train
Power
amplifier
Torque
(current)
feedback
Servomotor
1
Set the user constants for Servopack to switch between the following torque control
modes:
(1) Controlling servomotor torque by torque reference
(Torque control I)
(2) Operating servomotor by switching between torque reference and speed refer-
ence
(Torque control II)
The host controller outputs a torque reference or speed reference to control the Servopack.
It also receives a pulse train (position information) from the Servopack and uses it to monitor the position.
13
1
FOR FIRST−TIME USERS OF AC SERVOS
1.1.3 Features of Σ-Series Servos cont.
5) Servopack for position control can be used as below.
• Using Servopack for Position Control
Position
reference
Position
information
Pulse
train
Host controller
Position
monitoring
Speed/current loop
Pulse train
Position feedback
Servopack for
position control
Power
amplifier
Servomotor
Encoder
The host controller can send a position reference (pulse train) to the Servopack to perform positioning or interpolation.
This type of Servopack contains a position control loop.
User constants can be used to select either of the following pulse trains:
(1) Code and pulse train
(2) Two-phase pulse train with 90° phase difference
(3) Forward and reverse pulse trains
The host controller receives a pulse train (position information) from the Servopack and
uses it to monitor the position.
6) A Digital Operator can be used to set user constants for a Servopack as follows:
(1) Setting user constants to enable or disable each function
14
(2) Setting user constants required for functions to be used
Set user constants according to the servo system to be set up.
BASIC USES OF Σ-SERIES
PRODUCTS
This chapter describes the first things to do when Σ-Series products are delivered. It also explains the most fundamental ways of connecting and operating
Σ-Series products. Both first-time and experienced servo users
this chapter.
2.1 Precautions 16...............................
2.2 Installation 18...............................
2.1.1 Notes on Use 16.......................................
2.2.1 Checking on Delivery 18................................
2.2.2 Installing the Servomotor 19.............................
2.2.3 Installing the Servopack 22..............................
2
must read
2
2.3 Connection and Wiring 25.....................
2.3.1 Connecting to Peripheral Devices 25......................
2.3.2 Main Circuit Wiring and Power ON Sequence 28............
2.3.3 Examples of Connecting I/O Signal Terminals 30............
2.4 Conducting a Test Run 37.....................
2.4.1 Test Run in Two Steps 37...............................
2.4.2 Step 1: Conducting a Test Run for Motor without Load 39.....
2.4.3 Step 2: Conducting a Test Run with the Motor Connected
to the Machine 44.....................................
2.4.4 Supplementary Information on Test Run 46.................
2.4.5 Minimum User Constants Required and Input Signals 48......
15
BASIC USES OF Σ-SERIES PRODUCTS
2.1.1 Notes on Use
2.1 Precautions
This section provides notes on using Σ-Series products.
2.1.1 Notes on Use 16...................................................
2.1.1 Notes on Use
NOTE Always note the following to ensure safe use.
2
Two types of supply voltage are available, 100 V and 200 V.
Both Σ-Series Servomotor and Servopack have
100 V and 200 V types. Be sure to use the correct
type.
Type NP
Always use the SGM Servomotor and SGDA Servopack in pairs.
The SGM Servomotor cannot run without the
SGDA Servopack.
Do not plug the SGM Servomotor directly into the
commercial power supply. (Direct connection to
the commercial power supply will damage the
Servomotor.)
200 V or
100 V power
supply
Do not change wiring when power is ON.
Always turn the power OFF before connecting or
disconnecting a connector.
(Except for Digital Operator (Types: JUSPOP02A-1, JUSP-OP03A))
Voltage
label
Direct
connection
Damage will result!
Extinguished
Always turn the
power OFF
before
connecting or
disconnecting a
connector.
16
Note that residual voltage still remains in the Servopack even after the power is
turned OFF.
Even after the power is turned OFF, residual voltage still remains in the capacitor inside the Servopack. If inspection is to be performed after the
power is turned OFF, always wait at least 5 min-
Careful!
Residual
voltage remains
in capacitor
utes to avoid the risk of an electrical shock.
Wait at least 5
minutes
2.1 Precautions
Always follow the specified installation method.
Provide sufficient clearance
The Servopack generates heat. Install the Servopack so that it can radiate heat freely. Note also
that the Servopack must be in an environment
free from condensation, vibration and shock.
Ambient
temperature:
0to55°C
Perform noise reduction and grounding properly.
If the signal line is noisy, vibration or malfunction
will result.
D Separate high-voltage cables from low-voltage cables.
D Use cables as short as possible.
D Use at least class 3 grounding (ground resistance
100Ω or below) for the Servomotor and Servopack.
D Never use a line filter for the power supply in the
motor circuit.
Conduct a voltage resistance test under the following conditions.
D Voltage: 1,500 Vrms AC, one minute
D Braking current: 20 mA
D Frequency: 50/60 Hz
D Voltage applied point: Between R, T terminals and
frame ground (connect terminals R and T securely.)
10 mm
2
Conduct a
dielectric
strength test
as described
on the left.
Use a fast-response type ground-fault interrupter.
For a ground-fault interrupter, always use a fastresponse type or one designed for PWM inverters. Do not use a time-delay type.
Fast-response
type
Ground-fault interrupter
GOOD POOR
GOOD
For PWM
inverter
Do not perform continuous operation under overhanging load.
Continuous operation cannot be performed by rotating the motor from the load and applying regen-
Servomotor
erative braking. Regenerative braking by the Servopack can be applied only for a short period,
such as the motor deceleration time.
Regenerative braking
continuously applied
The Servomotor cannot be operated by turning the power ON and OFF.
Frequently turning the power ON and OFF causes
Servopack
the internal circuit elements to deteriorate. Always
start or stop the servomotor by using reference
pulses.
Power
supply
Time-delay
type
Starting and stopping by
turning power ON and OFF
17
2
BASIC USES OF Σ-SERIES PRODUCTS
2.2.1 Checking on Delivery
2.2 Installation
This section describes how to check Σ-Series products on delivery and how to install
them.
2.2.1 Checking on Delivery 18............................................
2.2.2 Installing the Servomotor 19.........................................
2.2.3 Installing the Servopack 22..........................................
2.2.1 Checking on Delivery
1) When Σ-Series products are delivered, check the following items:
Check Items
Check if the delivered products are
the ones you ordered.
Check if the motor shaft rotates
smoothly.
Check the types marked on the nameplates of
Servomotor and Servopack (see the table below).
If the motor shaft is smoothly turned by hand, it is
normal. However, if the motor has brakes, it cannot be
Remarks
turned manually.
Check for damage. Check the overall appearance, and check for damage
or scratches resulting from transportation.
Check screws for looseness. Check for looseness by using a screwdriver as
necessary.
If any of the above items are faulty or incorrect, contact the dealer from which you purchased the products or your nearest local sales representative.
Appearance Nameplate Type
Σ-Series
SGM: SGM
Servomotor
SGMP: SGM
Servomotor
Rated Output
A3:0.04HP A5:0.07HP
01:0.13HP 02:0.27HP
03:0.40HP 04:0.53HP
08:1.01HP
Power supply
A:200V B:100V
Encoder specifications
3: 2048P/R incremental encoder
W: 12-bit absolute encoder
Design revision order
Shaft specifications
2: Straight without key
4: Straight with key
6: Straight with key,
shaft end screw hole provided
Option
B: With brake S: With oil seal
D: With brake and oil seal
P: Drip-proof provision
Servo
motor
Σ-Series
SGM Servomotor
Σ-Series
SGMP Servomotor
Rated output
Servomotor
type
Serial number
Rated rotation
speed
Rated current
Rated torque
Manufacturing
date
18
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