Power Jacks EMA Actuators User Manual

Installation &
Maintenance

EMA

Electric Linear Actuators

EMA Linear Actuator

2

Contents

1. SAFETY AUTHORISED USE ...................................................................................... 3

1.1 RESIDUAL RISK AND HAZARDS................................................................................... 3

1.2 OPERATING PERSONNEL .......................................................................................... 3

1.3 COMMISSIONING ...................................................................................................... 4

1.4 MODIFICATIONS AND ALTERATIONS TO THE UNIT ........................................................ 4

2. DESCRIPTION ............................................................................................................ 5

3. TECHNICAL DATA ..................................................................................................... 6

3.1 MODEL I - INTERMITTENT (LESS THAN 10 STARTS/DAY, 10 HOURS/DAY) ....................... 6

3.2 MODEL C - CONTINUOUS (MORE THAN 10 STARTS/DAY) ............................................. 6

3.3 MODEL H - HIGH SPEED CONTINUOUS ................................ ...................................... 6

4. MOUNTING A SINGLE ACTUATOR ........................................................................... 7

4.1 UNPACKING AND INSTALLATION ................................................................................ 7

4.2 MOUNTING .............................................................................................................. 7

4.3 MOUNTING OPTIONS ................................................................................................ 8

5. ADJUSTING THE LIMIT SWITCHES .......................................................................... 9

6. ADJUSTING THE CLUTCH ...................................................................................... 10

6.1 EMA CLUTCH GENERAL ASSEMBLY ........................................................................ 11

6.2 EMA CLUTCH SETTINGS ................................ ........................................................ 11

7. ELECTRICAL INSTALLATION ................................ .................................................. 12

7.1 LIMIT SWITCH – ELECTRO-MECHANICAL TYPE ......................................................... 12

7.2 MOUNTING THE DRIVE MOTOR ................................................................................ 12

7.3 STANDARD MOTOR TERMINAL BOX POSITION .......................................................... 13

7.4 OPTIONS ............................................................................................................... 13

7.5 MOTOR CONNECTION............................................................................................. 13

7.5.1 Three Phase Motor Connections ................................................................... 13

7.5.2 Single Phase Motor Connections .................................................................. 14

7.5.3 DC Motor ....................................................................................................... 14

8. MAINTENANCE AND LUBRICATION ....................................................................... 14

9. PARTS LIST - GENERAL .......................................................................................... 15

9.1 EMA ELECTRIC LINEAR ACTUATOR (GENERAL ASSEMBLY) ...................................... 16

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EMA Linear Actuator

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1. Safety Authorised use

EMA electric linear actuators are exclusively designed for carrying out lifting, lowering
and feeding movements with the lifting forces up to 10 kN. Any other application other
than specified or one going beyond the above mentioned capacity is unauthorised. The
manufacturer is not liable for damages resulting from such applications. The user alone
has to bear the risk.

Since the actuators can be applied in various areas, the user is responsible for the
specific application of use.

In compliance with the regulations concerning the electromagnetic compatibility of
machines, the EMA linear actuators may only be used in industrial areas according to
the definition EN 50 081-2.

Safety instructions in the operating manual

This symbol indicates potential dangers to people. Comply with
the instructions in order to avoid injury.

This symbol indicates potential dangers to the unit. Comply with
the instructions in order to avoid damage to the unit.

This symbol indicates special information on:

 the best possible use of the unit
 how to facilitate operation of the unit

1.1 Residual risk and hazards

Should a risk of damage to material or injury to persons remain despite the structural
safety of the EMA actuators, the user must employ other safety measures and draw
attention to such hazards by means of suitable warning notices and written instructions
indicating safety precautions.

1.2 Operating personnel

The EMA electric linear actuators are designed according to state-of-the-art technology
and are in line with applicable safety regulations.

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However, the general risks of personal injury or damage to property connected with the
use of such machinery cannot be completely eliminated. Therefore the units may only be
assembled and operated by competent and qualified personnel and only be used for the
authorised application. Therefore a careful study of this operating manual should be
made before attempting to use or service the unit and particular attention should be paid
to the safety instructions.

Work to be performed on electrical parts, such as:

 installation of limit switches
 mounting of the drive
 Checking of the direction of rotation may only be carried out by qualified

electricians.

The linear actuators and the installation should be inspected by the operating and
supervising personnel for externally visible damage and defects at least once every shift.
Any changes (including the operational conditions) which may affect the safety are to be
reported immediately.

1.3 Commissioning

The EMA electric linear actuators must not be put into service before the machinery into
which it is to be incorporated fulfils all provisions of the EC directive relating to
machinery.

1.4 Modifications and alterations to the unit

It is not permitted to make any alterations to the safety features or design of the EMA
electric linear actuators without our written consent. Power Jacks declines any
responsibility in the event of such alterations. Worn and spare parts may only be
replaced after consultation with our service technicians or by them personally. It is not
permitted to disassemble or disconnect any safety or protection device. When using
special accessories the assembly instructions of the manufacturer must be observed!

The following regulations must be complied with:

 the relevant regulations for the prevention of accidents
 generally recognised safety regulations
 EC guidelines and
 National regulations

To comply with the regulations concerning the electromagnetic compatibility of
machines, the units must be connected according to EC rules & regulations. Therefore
the norms EN 50 081-2 and EN 50 082-2 should be observed, to avoid electromagnetic
interference.

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2. Description

EMA electric linear actuators are mainly used whenever precisely controlled lifting,
lowering or feeding movements are required. The actuators consist of either a
trapezoidal or ball lead screw, driven by an electric motor through spiroid gearing. The
screw converts the rotary motion into linear movement. As the screw rotates, the nut
extends and retracts the ram, which is attached to the load.

There are 3 standard EMA models, all available in a right-angle drive configuration.

 Intermittent model, incorporating a trapezoidal screw.
 Continuous model, incorporating a ball screw
 High Speed Continuous model, incorporating a ball screw.

Where the standard range does not meet the application specification, special actuators
can be designed to meet customers’ specific requirements.

As standard, the units are available with 240V / 415VAC 3phase or 240VAC 1 phase or
24VDC motors, with or without a brake. The type of motors required is dependent on the

customer’s application. The motors are mounted to the actuator on an IEC 63C Face

Flange Mounting.

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Dynamic Load

Capacity (kN)

Linear Speed

(mm/min)

Motor (kW)

Frame Size

Motor

Frame Size

Motor
Poles

Max. Stroke (mm)

(in compression)

10

135

0.18

D63 6 750

5

200

0.18

D63 4 750

5

270

0.18

D63 6 750

5

410

0.18

D63 2 750

2.5

820

0.18

D63 2 750

Dynamic Load

Capacity (kN)

Linear Speed

(mm/min)

Motor (kW)
Frame Size

Motor Frame

Size

Motor
Poles

Max. Stroke (mm)

(in compression)

10

225

0.18

D63 6 900

10

335

0.18

D63 4 900

10

685

0.18

D63 2 900

5

1370

0.18

D63 2 1250

2.5

2740

0.18

D63 2 1500

Dynamic Load

Capacity (kN)

Linear Speed

(mm/min)

Motor (kW)
Frame Size

Motor Frame

Size

Motor
Poles

Max. Stroke (mm)

(in compression)

10

900

0.25

D71 6 900

10

1375

0.37

D71 2 900

10

2755

0.55

D71 2 900

5

1805

0.18

D71 6 1250

5

5510

0.37

D71 2 1250

3. Technical Data

3.1 Model I - Intermittent (less than 10 starts/day, 10 hours/day)

3.2 Model C - Continuous (more than 10 starts/day)

3.3 Model H - High Speed Continuous

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4. Mounting a single actuator

4.1 Unpacking and Installation

Remove the EMA electric linear actuator from its container. Dispose of the packaging
material and the desiccant in an environmentally friendly way. If it is necessary and in
order to avoid damages, please use soft straps to transport or mount the actuator.

In order to avoid damage; do not attach the straps to the inner tube but to the
outer housing of the drive or to the gearbox.

4.2 Mounting

There are two possible ways of mounting the EMA actuator at the gearbox end:
By means of bearing journals for trunnion mounting or clevis mount.

Rear Clevis

 Mount the actuator by attaching the desired bracket and pin to the clevis end. Refer

to section 4.2.1 for ram mounting options.

 Verify that the ram attachment is aligned throughout the actuator stroke before

connecting the ram. The ram attachment will either be pinned or bolted in place
depending on chosen model.

Trunnion Mount

 Mount the actuator by attaching the desired bearings (or mounting feet) to the

trunnion pins. Refer to section 4.2.1 for ram mounting options.

 Verify that the ram attachment is aligned throughout the actuator stroke before

connecting the ram. The ram attachment will either be pinned or bolted in place
depending on chosen model.

Always ensure that clevis holes align correctly and that they allow for the
correct angle of pivoting for the application before operating the actuator.

Side loads on the actuator ram should be avoided by ensuring that the
load is guided. The load guide mechanism should resist the torque
developed at the ram by the screw mechanism. A guided ram can be
supplied on request, which utilises a keyway in the inner ram, eliminates
the need for torsional restraint and therefore allows flexibility in the choice
of end fitting.

The desired mounting orientation will be determined when placing the order; this
orientation must be maintained at installation.

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EMA Linear Actuator

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Clevis

End

Fork

End

Threaded

End

Top Plate

Trunnion

Mount

Rear Clevis at 90°

Standard Rear Clevis

4.3 Mounting Options

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5. Adjusting the limit switches

Electrical connections may only be performed by licensed electricians.

Standard mechanical limit switches are used to cut off the electrical drive before the final
position is reached. The limit switch is triggered by a cam on the lifting nut assembly.
The positions of these limit switches are fixed and are not adjustable. The position is
determined by the length of stroke specified by order and cannot be changed at a later
date. The mounting of a position-measuring system is possible as an option.

Suitably rated mechanical safety limit switches must be used if the non­disconnection of the electrical drive constitutes a potential danger to
people.

Adjusting the best possible sensing distance:

1. Position the cam on the lifting nut assembly to cover the opening of the switch.

2. Screw the switch into the housing until the unit switches over.

3. Lock the switch in place with the lock nut.

4. Check the correct function of the switches by moving the lifting-nut assembly
manually.

5. If the switch works correctly then repeat the procedure for the next switch.
Otherwise repeat procedure for this switch.

6. Once all the limit switches are set ensure that the cam on the lifting nut is resting
in a position in between both end of travel limit switches.

The drive must not be put into service before all limit switches have been
mounted and correctly adjusted.

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6. Adjusting the Clutch

The clutch is a device mounted on the actuator inner tube (ram) which will slip when the
torque to drive the load exceeds the limit set. (refer 6.1)

The clutch spindle, (6) that is attached to the load via an end fitting, is supported on
bearings (8) and clamped from rotating by interlocking conical rings (7). The clamping
load is applied by a locknut (5) with keyways to engage a tab washer (4). The clutch
housing (3) is attached to the inner tube (1) and the clamping effort of the conical rings
(7) carries the residual torque of lifting to the clutch spindle (6).

If the load is axially locked or if a torque greater than the clutch setting is required to
move the load, the conical rings will rotate within each other, disengaging the spindle to
inner tube drive and preventing the motor from overloading the actuator components or
the load guides etc.

Under normal operation and with no overload experienced the clutch requires no regular
maintenance or adjustment. If however the clutch slips regularly in operation the setting
of the clutch will reduce to a point where the normal operating torque will overcome the
clutch and the load will not move. Under these circumstances the clutch can be adjusted
as follows:

1. Remove the actuator from the installation.

2. Extend the inner tube (1) and clamp in soft jaws in a vice.

3. Bend out the tab of the washer (4) from the keyway of locknut (5).

4. With a suitable fitting screwed on to the clutch spindle (6) tighten the locknut until
a torque is indicated in table 1 (refer 6.2) is measured, e.g. Clutch lever forces in
table are for a 254mm (10in) lever inserted through clevis.

5. When the torque has been set, bend a tab of the washer into an adjacent keyway
in the locknut. The actuator is ready to reinstall.

6. The clutch is selected from either of the following:
a) Ringspan Cone Clamping Element TLK 250:-

i) 4202015.001 - 27Nm max.
ii) 4202025.001 - 74Nm max.

7. When assembling the clutch a small quantity of oil (3 in 1) should be
applied to the cone (7) surfaces.

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Actuator

Rating

Lead

Type

Torque

Clutch Lever Force

(kg

(mm)

-

(Nm)

lbs

kg

250 3 T

7.8 7 3

250 5 B

4.9 4 2

250 6 T

15.6

14

6

250

10 B 9.8 9 4

250

12

T

31.2

28

13

250

20

B

19.5

17

8

250

25

B

24.4

22

10

500 3 T

15.6

14

6

500 5 B

9.8 9 4

500 6 T

31.2

28

13

500

10

B

19.5

17

8

500

12

T

62.4

55

25

500

20 B 39

35

16

500

25

B

48.8

43

20

1000 5 B

19.5

17

8

Item Number

Description

1
2
3
4
5
6
7
8

Inner Tube (ram)
Distance Piece
Clutch Housing
Tab Washer
Lock Nut
Clutch Spindle
Conical Rings
Thrust Bearing

6.1 EMA Clutch General Assembly

6.2 EMA Clutch Settings

Type:

T - Trapezoidal
B - Ball Screw

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Item

Description

Housing

Metal, compact housing, totally
enclosed and sealed.

Pre-Cabled

2m PVC cable 5x0.75mm2 (other
cable lengths available on
request).

Switch type

Single-pole, 1 change-over, snap
action.

Switch Actuation

End of plunger (metal).

Max actuation speed

0.5 m/s

Mechanical durability

10 million operating cycles.

Ambient temperature
Operation
Storage

-25°C  +70°C

-40°C  +70°C

Product conformity

IEC947-5-1

Enclosure

IP67

Operating characteristics

AC-15; B300 (Ue=240V, Ie=1.5A)
DC-13; R300 (Ue=250V, Ie=0.1A)

Insulation voltage

Ui=300V

7. Electrical Installation

7.1 Limit Switch – Electro-Mechanical Type

7.2 Mounting the drive motor

The electrical installations and the checking of the direction of rotation
may only be carried out be a licensed electrician.

Connect the motor in compliance with the electro-technical regulation

Before mounting the motor, check the direction of rotation / linear travel of the EMA
actuator and the operation of the limit switches (if fitted). In order to do this:

1. Place the motor at the mounting position near the gearbox input.

2. Switch on the motor and check the direction of rotation.

3. Check the direction of rotation / linear travel by manually turning the gearbox input

shaft. Change the direction of the motor rotation if necessary by changing motor
connections.

4. Where necessary, attach coupling halves to motor shaft.

5. Mount motor onto gearbox input flange using screws provided.

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W2

U2

V2

U1

V1

W1

U1

V1

W1

W2

U2

V2

7.3 Standard Motor Terminal Box Position

7.4 Options

 Delivery with mounted brake motor (DC or AC brake).
 Delivery with non-standard motor types e.g. servo motor, 48VDC motor.
 Special request, motor being supplied by the customer.

7.5 Motor Connection

The electrical connections for the standard three-phase, single-phase or DC-permanent­magnet motor are within the terminal box. Appropriate rated and insulated cables require
to be selected in accordance with the rated power. If motors are supplied with flying
leads please consult Power Jacks.

All electrical connections are to be carried out by a qualified electrician.

7.5.1 Three Phase Motor Connections

Star and Delta connections for dual wound motors

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L1

L2

L1

L2

L1

L1

L2

L2

Forward

Reverse

Motor

+ve

-ve

7.5.2 Single Phase Motor Connections

This diagram is typical for motors with on board capacitors connected to the motor for
the correct start and run characteristics. For motors with loose capacitors consult Power
Jacks or the motor manufacturer.

7.5.3 DC Motor

8. Maintenance and Lubrication

Unless otherwise specified the actuators are shipped with their full requirement of
grease for normal operation. The actuators should not need a lubrication refill within their
standard life provided they have been installed and used correctly. Should the unit
require lubrication then use one of the following extreme pressure greases or their
equivalent:

Shell Alvania WR2
BP Energrease LC2
Castrol Spheerol L-EP2
Mobil Mobilux EP2

If ambient temperatures exceed 50°C (122°F) consult Power Jacks.

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EMA Linear Actuator

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Item

Description

1.

Gearbox housing

2.

Rear clevis guide bush.

3.

Pinnion bearing

4.

Pinnion

5.

Pinnion bearing

6.

Shims

7.

Thrust ring

8.

Circlip

9.

Grub screw for locking bearing cap.

10.

Shims

11.

Rear bearing for gear

12.

Grub screw for locking gear to lifting screw.

13.

Gear

14.

Front bearing for gear.

15.

Bearing end cap

16.

Lead screw (trapezoidal or ball screw).

17.

Emergency end stop pin

18.

Outer tube

19.

Guide bush for ram

20.

Seal/wiper unit for ram

21.

Lifting nut

22.

Grub screw for locking ram to lifting nut.

23.

Inner tube (ram)

24.

Clutch - Distance piece

25.

Clutch - Bearing washer (raceway)

26.

Clutch - Bearing cage assembly

27.

Clutch - Spindle

28.

Clutch - Housing

29.

Clutch - Ring Assembly (Lock nut, tab washer, conical ring)

30.

Ram end (clevis, fork end or top plate)

31.

Grub screw for locking ram end.

32.

Electric motor

33.

Trunnion Ring - Not shown on diagram (welded to outer
tube at customer specified point)

9. Parts List - General

(refer to section 9.1 for EMA Electric Linear Actuator general assembly diagram)

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EMA Linear Actuator

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9.1 EMA Electric Linear Actuator (General Assembly)

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Power Jacks Ltd
Balmacassie Commercial Park
Ellon AB41 8BX
Scotland

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MM-LA-EMA-04-b