Exlar GSM20 Manual

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GSM Series Linear Actuator
Installation and Service Manual
Information furnished by Exlar Corporation is believed to be accurate and reliable.
However, no responsibility is assumed by Exlar Corporation for its use. Exlar reserves the
right to change the design and operation of the equipment described herein and any
associated motion products that may appear in this document. Information in this document
pertaining to equipment not furnished by Exlar should be confirmed by that equipment
manufacturer. Exlar assumes no responsibility for changes to information by other
manufacturers or errors in that information or the description of that information. Information
in this document is subject to change without notice.
This document does not contain any export controlled data.

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TABLE OF CONTENTS
1.0 Introduction .......................................................................................3
1.1 Warranty and Limitations of Liability.............................................3
1.2 Safety Considerations ..................................................................4
2.0 System Configuration.......................................................................4
2.1 Typical System Configuration.......................................................4
2.2 Typical System Wiring..................................................................5
2.3 Feedback Information...................................................................5
2.4 Cable Routing...............................................................................7
2.5 Anti-Rotation Option .....................................................................7
2.6 External Limit Switch Option.........................................................8
2.7 Rear Brake Option......................................................................10
2.8 Ingress Protection.......................................................................12
3.0 Installation and Operation..............................................................13
3.1 Lubrication Requirements...........................................................13
3.2 Mounting Configurations.............................................................13
3.3 Mounting Considerations............................................................13
3.4 General Operation......................................................................14
3.5 Manual Drive Operating Instructions..........................................15
4.0 Maintenance Procedures................................................................16
4.1 Disassembly ...............................................................................16
4.2 Lubrication Maintenance ............................................................17
4.3 Reassembly................................................................................18
4.4 Seal Maintenance.......................................................................19
5.0 Class I Division 2 Option................................................................21
5.1 Terminal Box Wiring Diagram.....................................................22
5.2 Class I Division 2 Terminal Box Terminations............................22
5.3 Terminal Box Dimensions...........................................................24
6.0 Troubleshooting Procedures.........................................................25
6.1 Returning a Product for Repair...................................................26
7.0 Certifications ...................................................................................28
Refer to www.exlar.com for connector and wiring information.

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1.0 INTRODUCTION
1.1 Warranty and Limitation of Liability
Products are warranted for two years from date of manufacture as determined by the serial
number on the product label. Labels are generated and applied to the product at the time of
shipment. The first and second digits are the year and the third and fourth digits represent the
manufacturing week. Product repairs are warranted for 90 days from the date of the repair. The
date of repair is recorded within Exlar’s database tracked by individual product serial number.
Exlar Corporation warrants its product(s) to the original purchaser and in the case of original
equipment manufacturers, to their original customer to be free from defects in material and
workmanship and to be made only in accordance with Exlar's standard published catalog
specifications for the product(s) as published at the time of purchase. Warranty or performance to
any other specifications is not covered by this warranty unless otherwise agreed to in writing by
Exlar and documented as part of any and all contracts, including but not limited to purchase
orders, sales orders, order confirmations, purchase contracts and purchase agreements. In no
event shall Exlar be liable or have any responsibility under such warranty if the product(s) has
been improperly stored, installed, used or maintained, or if Buyer has permitted any unauthorized
modifications, adjustments and/or repairs to such product(s). Seller's obligation hereunder is
limited solely to repairing or replacing (at its opinion), at the factory any product(s), or parts
thereof, which prove to Seller's satisfaction to be defective as a result of defective materials, or
workmanship and within the period of time, in accordance with the Seller's stated product
warranty (see Terms and Conditions above), provided, however, that written notice of claimed
defects shall have been given to Exlar within thirty (30) days from the date of any such defect is
first discovered. The product(s) claimed to be defective must be returned to Exlar, transportation
prepaid by Buyer, with written specification of the claimed defect. Evidence acceptable to Exlar
must be furnished that the claimed defects were not caused by misuse, abuse, or neglect by
anyone other than Exlar.
Components such as seals, wipers, bearings, brakes, bushings, gears, splines, and roller
screw parts are considered wear parts and must be inspected and serviced on a regular basis.
Any damage caused by failure to properly lubricate Exlar products and/or to replace wear parts at
appropriate times, is not covered by this warranty. Any damage due to excessive loading is not
covered by this warranty.
The use of products or components under load such that they reach the end of their expected
life is a normal characteristic of the application of mechanical products. Reaching the end of a
product’s expected life does not indicate any defect in material or workmanship and is not
covered by this warranty.
Costs for shipment of units returned to the factory for warranty repairs are the responsibility of
the owner of the product. Exlar will return ship all warranty repairs or replacements via UPS
Ground at no cost to the customer.
For international customers, Exlar will return ship warranty repairs or replacements via UPS
Expedited Service and cover the associated shipping costs. Any VAT or local country taxes are
the responsibility of the owner of the product.
The foregoing warranty is in lieu of all other warranties (except as Title), whether expressed or
implied, including without limitation, any warranty of merchantability, or of fitness for any particular
purpose, other than as expressly set forth and to the extent specified herein, and is in lieu of all
other obligations or liabilities on the part of Exlar.
Seller's maximum liability with respect to these terms and conditions and any resulting sale,
arising from any cause whatsoever, including without limitation, breach of contract or negligence,
shall not exceed the price specified herein of the product(s) giving rise to the claim, and in no
event shall Exlar be liable under this warranty otherwise for special, incidental or consequential
damages, whether similar or dissimilar, of any nature arising or resulting from the purchase,
installation, removal, repair, operation, use or breakdown of the product(s) or any other cause
whatsoever, including negligence.
The foregoing warranty shall also apply to products or parts which have been repaired or
replaced pursuant to such warranty, and within the period of time, in accordance with Seller's
stated warranty.
NO PERSON INCLUDING ANY AGENT OR REPRESENTATIVE OF EXLAR IS
AUTHORIZED TO MAKE ANY REPRESENTATION OR WARRANTY ON BEHALF OF EXLAR
CONCERNING ANY PRODUCTS MANUFACTURED BY EXLAR, EXCEPT TO REFER
PURCHASERS TO THIS WARRANTY.

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1.2 Safety Considerations
As with any electro-mechanical device, safety should be considered
during the installation and operation of your GSM Series actuator.
Throughout this manual you will see paragraphs marked with CAUTION
and WARNING signs as shown below.
Pay particular attention to these paragraphs. They are intended to
provide you with helpful information to ensure safe and trouble-free
installation.
2.0 SYSTEM CONFIGURATION
2.1 GSM Series Actuator System Configuration
GSM Series actuators incorporate an integral brushless servo motor.
The design of this motor and selection of the proper feedback
configuration allows GSM Series actuators to be powered by nearly
every brand of brushless motor amplifier on the market.
This flexibility allows GSM Series actuators to be incorporated into the
highest performance single and multi- axis motion control systems in use
today. In applications varying from food and beverage packaging to
multi-axis turning centers to aircraft assembly, the GSM Series of
actuators show incredible performance and durability.
The high torque to volume ratio available from a brushless motor,
combined with the robust, high speed and high load capability of the
planetary roller screw, make the Exlar line of linear actuators a true, all
electric replacement for cumbersome high maintenance hydraulics. The
use of electronic servo control provides simpler set up and more precise
control than hydraulic systems as well.
The schematic, next page, shows the typical connections for a single
axis system incorporating an Exlar GSM Series actuator and servo
amplifier. Each brand of brushless motor amplifiers may have unique
wiring requirements, parameter settings and operational principals that
affect how the actuator operates. The drawing on the following page
shows general connection principals for typical resolver and encoder
feedback amplifiers. Details on connections to specific brands of
amplifiers can be obtained from www.exlar.com.
CAUTION
WARNING

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WARNING: Attempting to connect the power cable to the
motor feedback connector may cause damage to the
connector. Verify that pin patterns match before attempting to
connect cables to actuator.
Never attempt to connect or disconnect the actuator with power
applied. Dangerous voltages are present. Damage to equipment and
injury to personnel can result. Many amplifiers have voltage present
for a considerable time period after incoming power is removed.
Take care to insure that the amplifier has discharged all power.
2.2 Typical System Wiring
Please refer to www.exlar.com for information on connectors and
wiring.
2.3 Feedback Information
GSM Series actuators incorporate a quadrature incremental encoder
with commutation signals as the primary rotary feedback device. The
alignment of this feedback device is dictated by the amplifier that the end
user chooses for operating the actuator. This amplifier is indicated in the
model number of the GSM Series actuator as a 3 digit code consisting of
2 letters and 1 number.
Typical System Connections

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Each amplifier has specific requirements for the feedback on the
motor. Not all encoder-based amplifiers can use the same encoder,
encoder alignment or relative direction of encoder rotation.
Many amplifiers offer software that allows the entering of parameters
or the downloading of motor data files that dictate how the feedback
must be set up on the motor. Exlar can provide many of these data files
or the proper parameters to enter. Entering motor parameter data to
some amplifiers may require assistance from the amplifier manufacturer.
Feedback Alignment
When Exlar manufactures a GSM Series actuator, the proper
feedback is selected, mounted, aligned and test run on the amplifier that
the customer plans to use, or one that is known to be equivalent for
confirming proper feedback alignment and operation. In any case where
it is determined that the feedback has become misaligned, or an
amplifier change is made requiring the feedback to be aligned differently,
it is recommended that Exlar be contacted and arrangements made to
have that procedure performed.
Feedback Wiring
The wiring of the feedback device is critical to the operation of the
actuator with the selected amplifier. Wiring the feedback cable
improperly can cause unstable operation, incorrect operation or no
operation at all. In some cases, if the proper current limits are not set in
the amplifier, improper wiring of the feedback cable can lead to damage
of the motor.
Encoders
An incremental encoder is an electronic rotary device that transmits a
string of electrical pulses when rotated. Most brushless motors or servo
systems that use incremental encoders use what is called a quadrature
encoder. Typical brushless motor encoders use two data channels,
labeled A&B, to provide direction, velocity and position information. The
Channel labeled I or Z has one pulse per revolution and is called the
index. The channels labeled as hall signals, or commutation signals, are
typically labeled S1, S2 & S3; Hall 1, 2 & 3, or Hall A, B & C, depending
on the manufacturer's conventions. These signals give the amplifier the
commutation information that it needs to properly rotate the motor.

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GSM Series Feedback Devices
Standard GSM Series actuators use encoders as their primary feedback
device. Depending on the amplifier that will be used to operate the
actuator, the hookup of the actuator can vary. Always consult Exlar for
the correct wiring details or visit www.exlar.com.
2.4 Cable Routing
Over time, liquid contaminants such as oil and cleaning solutions will
run down the cables and into any exposed connectors. To minimize the
introduction of contaminants to the connector, route the cables so that
there is a loop in the cable just prior to its attachment to the connector.
Two examples are shown below, depending on the orientation of the
connectors. Units mounted in such a way that the connectors are on the
bottom surface of the actuator require no looping.
2.5 GSM Series Linear Actuator Anti-rotation Option
The unique design of the GSM Series linear actuators allows the
extending rod to rotate. This simplifies the setup of the actuator by
allowing the user to rotate the rod and thread it in and out of the actuator
for mechanical attachment or system testing.
This feature also requires that the rod be kept from rotating when used
in its dedicated application to insure proper linear motion. In most
applications, such as those where the load is coupled to linear bearings
or some other support device, the load cannot rotate, providing anti-
rotation for the extending rod of the actuator.
For applications in which the load is free to rotate, Exlar offers the anti-
rotation systems shown below. The drawings on the next page show the
rod and bushing on only one side of the actuator. For long stroke
actuators, the rod and bushing are required on both sides of the actuator.
Top Mount Side Mount
Loop Loop

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2.6 GSM Linear Actuator External Limit Switch
With the anti-rotate option (Section 2.6) the GSM actuator can
accommodate 1, 2 or 3 external limit switches for use as end of
travel limit switches or home position sensors in low profile
extruded channel housing. A bracket with inductive proximity
switches mounts to the tie rods and senses a traveling magnet
inside the extrusion.
Anti-Rotate Option Dimensions
Dimensions in
inches
GSM20
GSM30
GSM40
A
0.60
0.79
1.25
B
1.81
2.54
3.78
C
0.54
0.71
0.98
D
1.00
1.29
1.65
E
0.44
0.44
0.63
F
0.28
0.32
0.38
G
0.31
1.69
1.69
H
0.37
0.50
0.50

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External Limit Switch Dimensions
The number of switches desired is selected by ordering the L1, L2 or
L3 option, in which 1, 2, or 3 switches will be provided, respectively.
The switches are 9-30 VDC powered, PNP output, with either normally
open or normally closed logic operation depending on the switch
configuration ordered. Below is a diagram indicating which logic
operation will be provided for each switch, based on the option ordered.
DIM "A" 3" Stroke 6" Stroke 10" Stroke 12" Stroke 18" Stroke
GSM20 5.515 8.515 n/a 14.515 n/a
GSM30 6.932 9.832 13.832 15.832 21.832
GSM40 n/a 9.832 13.832 15.832 21.832

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Configuration of Logic of Standard Switch Option Selections
Option
SW1
SW2
SW3
L1
Not Supplied
Normally Open
Not Supplied
L2
Normally Closed
Not Supplied
Normally Closed
L3
Normally Closed
Normally Open
Normally Closed
Switch Type
Exlar Part
Number
Turck Part Number
Normally Closed Switch
43404
BIM-UNT-RP6X
Normally Open Switch
43403
BIM-UNT-AP6X
2.7 Internal Holding Brake
Many applications require the addition of the rear internal holding
brake. The brake is held open by the supply of power to a
magnetic/mechanical clutch. Whenever there is not power to the brake,
the armature is held in place to prevent the inverted roller screw from
turning and prevent the output rod from back driving, which therefore
prevents the output rod from moving.
The holding brake is permanent magnet engaged and electrically
released. The mechanical advantage of the roller screw allows the
holding brake to prevent back driving of the load. The holding capacity of
the brake is sufficient to hold the rated force of the actuator when used in
grease lubricated units.
Historically, Exlar actuators and motors with holding brakes provided a
transient suppression diode wired internally to the actuator or motor.
With the changes in servo amplifier and control technology, there are
now instances where the diode is not required to be within the motor. An
example of this is a control system using a dedicated brake control relay
containing transient suppression components.
Because of this change in technology, Exlar now provides the
transient suppression diode separately from the actuator, for inclusion in
the brake control circuitry as needed by the end user. A schematic is
provided below showing the typical use of the transient suppression
diode.

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If the user is uncertain about the requirements for transient
suppression, they should refer to their servo amplifier or controller
technical documentation, or contact their servo amplifier or controller
manufacturer for technical support.
For connection of your amplifier and actuator (including rear brake
leads), refer to the wiring information at www.exlar.com/cables-
connections/.
The rear brake option adds length to the dimensions of the GSM
actuators as follows: (See drawings in Section 5.2.)
GSM20: Add 1.784 inches (45.3 mm) if ordering brake
GSM30: Add 1.6 inches (40.6mm) if ordering brake
GSM40: Add 2.33 inches (59.2 mm) if ordering brake
BRAKE
SPECIFICATIONS
GSM20
GSM30
GSM40
Holding torque
19 lb-in
70 lb-in
97 lb-in
Voltage
24 VDC
24 VDC
24 VDC
Current required
0.75 Amps
0.75 Amps
0.88 Amps
Coil resistance
(polarity sensitive)
70.6 Ohms
48 Ohms
36 Ohms

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DO NOT attempt to operate the actuator with the
brake applied. Allowing the actuator to operate
with the brake applied may cause serious damage
to the actuator and/or the brake. Do not use the brake to
support heavy loads while an operator is under the load.
Provide another means to lock the load in position. The
brake is a spring applied friction mechanism and does not
provide a positive lock.
2.8 Ingress Protection Rating
The standard IP rating for GSM Series actuators is IP54S with an
option for IP65S. Ingress protection is divided into two categories; solids
and liquids. For example, in IP65 the three digits following “IP” represent
different forms of environmental influence:
•The first digit represents protection against ingress of solid objects.
•The second digit represents protection against ingress of liquids.
•The suffix digit represents conditions of motion during the operation.
Digit 1 - Ingress of Solid Objects
The IP rating system provides for 6 levels of protection against solids.
1
Protected against solid objects over 50mm e.g. hands,
large tools.
2
Protected against solid objects over 12.5mm e.g. hands,
large tools.
3
Protected against solid objects over 2.5mm e.g. wire,
small tools.
4
Protected against solid objects over 1.0mm e.g. wires.
5
Limited protection against dust ingress.
6
Totally protected against dust ingress.
Digit 2 - Ingress of Liquids
The IP rating system provides for 9 levels of protection against liquids.
1
Protected against vertically falling drops of water or
condensation.
2
Protected against falling drops of water, if the case is
disposed up to 15 degrees from vertical.
3
Protected against sprays of water from any direction, even if
the case is disposed up to 60 degrees from vertical.
4
Protected against splash water from any direction.
5
Protected against low pressure water jets from any
direction. Limited ingress permitted.

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6
Protected against high pressure water jets from any
direction. Limited ingress permitted.
7
Protected against short periods of immersion in water of 1m
or less for 30 minutes or less.
8
Protected against long durations of immersion in water.
9
High-pressure, high-temperature wash-down applications.
Suffix
S
Device standing still during operation
M
Device moving during operation
3.0 INSTALLATION AND OPERATION
3.1 Lubrication Requirements
The GSM Series actuator is shipped from the factory fully greased
and ready for installation. Exlar recommends using Mobilith SHC 220,
a high performance, extreme-pressure grease. The unique physical
properties of the synthetic base oil provide outstanding protection against
wear, rust, corrosion and high or low-temperature degradation. Mobilith
SHC allows for very low starting and running torque values. Its operating
range is -40° C to 177° C (-40° F to 350° F).
3.2 Mounting Configurations
The standard configurations available are Rear Clevis, Front Flange,
Extended Tie Rods, Side Trunnions and side tapped mounting holes.
General drawings are shown in the product section guide.
3.3 Mounting Considerations
Every effort should be made to minimize misalignment. Any
misalignment will decrease the life of the components within the actuator
and also may create problems within the application associated with
misalignment.
Excessive side load on the output rod of the actuator will
dramatically reduce the life of the actuator and should be
avoided completely. Side load can be caused from
misalignment or loading that is not inline with the actuator
output rod.

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3.4 General Operation
The GSM Series linear actuators function in the same manner as a
brushless servomotor. The servo amplifier is used to rotate the motor at
controlled speed and torque, and for controlled numbers of revolutions
and move times. This rotary motion is translated into linear motion by the
internal planetary roller screw mechanism of the GSM Series linear
actuator.
The relationships between the rotary motion of the motor and the
linear motion of the actuator correspond to the following relationships:
Linear Distance Traveled (in) = (Motor Revolutions)*(Roller
Screw Lead)
Linear Speed (in/sec) = ((Motor RPM) / 60)*(Roller Screw Lead)
Linear Force (lbf) = ((Motor Torque (in-lbf))*(2)*(efficiency)) / (Roller
Screw Lead (in))
All of the above relationships require proper anti-rotation of the GSM
Series actuator rod.
For more information on sizing and selection of GSM Series actuators
and servo amplifiers, consult the sizing and selection section of the Exlar
catalog.
Motor RMS current must be maintained at a level below the
continuous current rating of the GSM Series actuator or
damage to the motor stator will result.
The peak current setting must be maintained at a level below the
peak current rating of the GSM Series actuator or damage to the
stator will result.
Care should be taken not to exceed the physical travel
limits of GSM Series Actuators. Doing so will cause the
actuator to end-crash internally. End crashes can physically
damage the roller screw and the internal components of the
actuator. Care should be taken to avoid high speed impact with
objects of high rigidity that immediately stop the travel of the
actuator with no deceleration or energy absorption. An example
would be a high speed impact of two solid steel parts. The resulting
impact will create a very short effective deceleration time. Kinetic
energy contained in the rotating inertia of the actuator and motor
can possibly generate extremely high impact forces that exceed the
mechanical capacities of the actuator and cause physical damage

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to the actuator. For applications requiring this type of impact,
contact Exlar application engineering to insure that the actuator is
properly sized or provisions are made to absorb the induced
energy.
3.5 Manual Drive Operating Instructions
Important: If manually driving through a brake or high
force is necessary, please consult Exlar engineering. If a
power tool is used to operate the manual drive the speed should be
limited to 600 RPM. An impact driver should never be used to
operate the manual drive.
Extreme caution should be taken when approaching end of stroke
of the actuator or system.
1) Press down on the hex until you feel you have bottomed out the
manual drive. Constant downward force is required to maintain
engagement during operation.
2) Give the hex a slight turn while observing if you are moving the
rod or not. It is possible that during engagement the gear teeth
have not completely engaged; this will prevent the gears from
meshing. If the rod is not moving continue to press down while
turning the manual drive slowly until it pushes farther down.
When this happens you have proper gear engagement.
3) After gear engagement is achieved, the manual drive can be
operated. The maximum torque input for the manual drive should
not exceed the values shown in Table 1.
4) When the manual drive movement is completed, cease the
downward force and the manual drive will disengage.
Table 1- Maximum operating conditions
Model
Maximum Torque
in-lbs / (Nm)
GSM 20
10 / (1.1)
GSM 30
30 / (3.4)
GSM 40
40 / (4.5)

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Push down
4.0 MAINTENANCE PROCEDURES
4.1 Disassembly
If your actuator has a preloaded roller screw, do not
remove it from the cylinder. Preloaded screws require
special tooling and procedures for proper disassembly and
reassembly. Contact Exlar to arrange for maintenance of a
preloaded screw actuator.
Refer to the exploded view on the page 20.
1. Remove the actuator assembly from the machine by
disconnecting the cables, main rod coupling and actuator
mounting bolts or fasteners.
2. If your unit does not have an external anti rotate assembly, skip
this step. Loosen the two machine screws that clamp the anti-
rotate cross member to the actuator output rod. Slide the anti-
rotate mechanism forward and off the actuator.
3. Remove the rear tie rod nuts from the back of the
actuator.
Disengaged
Engaged
Detailed Section View

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The end cap houses the feedback device. Alignment of this
feedback device to the phases of the motor is critical to the
operation of the system. Extreme care should be taken when
removing the tie rod nuts or tie rods so as not to twist or pull on the
end cap of the actuator. Some feedback devices are sensitive to
movement of their mounting surface once installed and can be
damaged if care is not taken.
4. If your actuator does not have a front flange, skip this step. Slide
the front flange forward and off the actuator. The tie rods will
remain attached to the front flange.
If your actuator has a preloaded roller screw, do not
remove it from the cylinder. Preloaded screws require
special tooling and procedures for proper disassembly and
reassembly. Contact Exlar to arrange for maintenance of a
preloaded screw actuator.
5. When the face plate is removed, the thrust bearing and the open
end of the roller screw internally threaded cylinder (ITC) are
visible. The roller screw can be removed by turning it counter
clockwise and threading it out of the cylinder. It may be
necessary to keep the roller screw cylinder from turning to
remove the screw.
4.2 Lubrication Maintenance
Grease lubricated units will require periodic inspection and renewal of
the bearing and roller screw grease. The table below shows the
recommended grease renewal period.
RMS Rotational
speed(RPM)
Recommended Grease Renewal Period hours)
CASE TEMP
65°C (149°F)
CASE TEMP
80°C (176°F)
CASE TEMP
95°C (203°F)
250
10,000
5,000
2,500
500
8,500
4,250
2,125
1000
6,000
3,000
1,500
1500+
3,500
1,750
875

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Grease Renewal
The bearings located in the front of the actuator, the roller screw
cylinder, and the roller screw assemblies are the components that
require grease. They require a coating of grease. They do not need to be
packed with grease. Excess grease requires more torque from the motor
when returned to operation, and does not improve the lubrication of
the unit.
1.) Use a brush to work approximately 0.5 in3of grease for every
3 inches of stroke length into the roller screw cylinder. Be sure to
cover all of the threaded areas of the cylinder.
2.) Use a brush to work grease in to the roller screw assembly. Be
sure to cover all the threaded surfaces of the screw assembly.
This can be accomplished by applying grease to a few places on
the roller screw assembly and rotating the components
repeatedly in both directions to work the grease into the
assembly.
3.) Force grease into the front of the thrust bearing assembly. Make
a concerted effort to insure that the grease is well worked in.
Grease must reach the bearing just behind the bearing that is
visible as well. Use the following amounts of grease for each size
roller screw and bearing:
GSM20: 0.5 in3
GSM30: 0.75 in3
GSM40: 1.00 in3
4.3 Reassembly
1.) Rethread the roller screw into the internally threaded cylinder
(ITC). It is a multiple start screw, and this is not always easy. DO
NOT FORCE THE ROLLER SCREW INTO THE CYLINDER. It
is best to have the actuator vertical with the open end of the
roller screw cylinder facing up. Position the roller screw above
the cylinder so that it is aligned axially with the ITC. Slowly turn
the roller screw 1/4 to 1/2 a turn counterclockwise with it in
contact with the ITC. This will help to align the threads on the
roller screw with the threads in the ITC. Rotate the roller screw
clockwise and it should begin to thread into the cylinder. If it does
not turn freely, remove it and begin again. When threading the
screw into the cylinder, it will roll freely into the actuator. When it
reaches the portion of the cylinder that contains the motor
magnets, the roller screw will be more difficult to turn because of
the magnetic field of the magnets. THIS IS NORMAL. Continue
to thread the roller screw into the cylinder. When it reaches the
bottom, it will become difficult to turn and the motor and bearings
will begin to rotate with it. The roller screw is now fully inserted
into the cylinder.

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2.) Place a small amount of seal lubricant on the inside surface of
the seal/bushing assembly.
3.) Carefully slide the face plate and bushing/seal assembly over the
actuator rod end, while guiding the tie rods through the holes in
the rear end cap of the actuator. The seal is a tight fit on the rod
end. Take care not to damage the seal on the threads of the
extending rod. Standard GSM Series rods have a chamfer to
provide a lead in for replacement of the seal and bushing. Be
sure that the faceplate seats completely and squarely on the
front of the actuator. The inner surface of the faceplate provides
the pre-loading for the bearings, and it is important that it is
properly seated.
Units with a Front Flange
Replace the faceplate as described above. Remount front flange by
sliding tie rods through the holes in the faceplate and through the holes
in the rear end cap. Pilot the flange on the pilot diameter located on the
front of the faceplate.
4.) Replace the rear tie rod washers and nuts and tighten to the
proper torque. Tighten the nuts simultaneously by partially
tightening each in an opposing corner pattern until each is
torqued to the rated value shown below.
GSM20: 30 lbf-in (2.5 lbf-ft, 3.39 N-m)
GSM30: 90 lbf-in (7.5 lbf-ft, 10.16 N-m)
GSM40: 240 lbf-in (20 lbf-ft, 27.12 N-m)
5.) If your actuator has an external anti-rotate mechanism, slide the
rod or rods of the anti-rotate mechanism through the front flange
and into the guide bushing or bushings mounted to the rear of
the flange. Position the extending rod so that the wrench flats are
parallel to the long side of the flange. Slide the cross member
assembly of the anti-rotate mechanism over the end of the rod
and onto the wrench flats. Tighten the two screws that clamp the
assembly to the actuator rod.
4.4 Seal Maintenance
If you have chosen the IP65 sealing option (-P5) on your GSM
actuator, it is recommended that the main rod seal and bushing
assembly be replaced at the suggested time of lubrication. The main rod
seal can be removed by threading it out of the face plate using a
standard rod seal gland wrench or spanner wrench. A new main rod seal
can be slid over the main rod, taking care not to touch the seal material
to the threaded rod end. To have this service performed for you, contact
Exlar Engineering or arrange with Exlar Returns Department to send
your unit in for service

Curtiss-Wright | GSM Series Rev. U PN29959 3/28/17
20
Note: Some actuators are provided with special seals due to chemical
exposure or other special requirements. Contact Exlar if there is a
question about your particular actuator having a standard material main
rod seal gland.
Main Rod Seal Gland Installation/Replacement:
1. Using proper sized gland or spanner wrench, remove existing
seal from actuator face plate, and slide off the actuator rod. This
will require the removal of any rod attachments. One source for
gland wrenches is Martin Fluid Power,
https://www.mfpseals.com/
Exlar
Actuator
Model
Martin Fluid
Power Part No.
Size
(in)
Description
GSM20-30
PH-0695900000
1/2, 5/8
Rod Gland
Wrench
GSM40
PH-0695910000
1
Rod Gland
Wrench
Standard Main
Rod Seal Gland
Part Numbers
Install Torque
GSM20
18929
100 lb-in (11.29 N-m)
GSM30
19020
200 lb-in (22.58 N-m)
GSM40
19021
360 lb-in (40.67 N-m)
Main Rod Seal Gland and Bushing