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GTW Series

Integrated Motor | Actuator

Industrial - Exlar

For C-Gun, X-Gun, or Pinch weld-guns systems

  • Programmability and precision of electric actuators.
  • Power density, durability, and form factor of hydraulic actuators.
  • Seamless integration with KUKA (KRC4 & KRC5), ABB, Comau, and Fanuc robot controllers as well as Bosch Rexroth and Festo 7th axis drive controllers.
  • Environmentally sealed for use in harsh industrial environments.
  • Built-in mounting features for adaption to a variety of weld-gun configuration.
  • The GTW actuator is “lubed for life” and requires no downtime for maintenance when used in a typical welding environment*
*Assumes 30 million weld cycles when operated within published performance ratings and recommended full stroke re-lubrication cycles.
More Details

Integrated servo motor actuator for weld guns

GTW Series electric linear servo actuators integrate with weld-gun robotic systems, Pinch, C-Gun, or X-Gun! These actuators have built-in mounting features for adaption to a variety of weld-gun configurations as well as robotic interfaces enabling quick and easy hookup. Offering 15x longer life than the ordinary ball screw and 3x the power density means the GTW Series actuators will last for over 30 million welds under typical weld profiles. 


Overview

GTW Series

Quick Data
ModelFrame Size mm (in)Peak Force N (lbf)Continuous Force N (lbf)Max Speed mm/s (in/s)
GTW08080 (3.15)
9,480 (2,132)
4,740 (1,066)
1,270 (50.0)
GTW100100 (3.94)
24,196 (5,440)
12,098 (2,720)

 953 (37.5)


Maximize Life | Minimize Maintenance Lubed for Life

Unlike traditional roller screws and ball screws that disperse lubricants during operation, the unique inverted roller screw design keeps lubrication where it is needed the most, increasing the life of the actuator and avoiding the downtime needed for periodic re-greasing. The premium seal and wiper design further increases the life of the GTW Series electric servo cylinder by preventing contaminants from entering the screw system.

Related Industries

Quick Data
Models:GTW080, GTW100
Frame Sizes:80 mm (3.15 in), 100 mm (3.9 in)
Stroke Lengths:

150, 300 mm (6, 12 IN)

Screw Lead:

2.54, 5.08, 12.70 mm (0.1, 0.2, 0.5 in)

Linear Speed:Up to 1,270 mm/s (50 in/s)
Peak Thrust Capacity:30,784 N  (6,920 lbf)
Standard/Rating:CE and UL Certifications, UL Class 180H insulation, IP66S

AAA = GTW Integrated Motor / Actuator
080 = 80 mm
100 = 100 mm

BBB = Stroke Length
150 = 150 mm
300 = 300 mm

CC = Screw Lead
01 = 0.10 in (2.54 mm)
02 = 0.20 in (5.08 mm)
05 = 0.50 in (12.7 mm)

D = Winding Voltage
4 = 460 VAC Max

E = Rod End Thread & Type
A = Male, Metric
B = Female, Metric
C = Male, Metric Splined1
D = Female, Metric Splined1
M = Male, English
G = Male, English Splined1
F = Female, English
H = Female, English Splined1

FF = Drive Manufacturer
AB = ABB
CM = Comau
FA =  Fanuc (64 & 128 Bit)
FE = Festo
IN = Bosch (Indramat)
KU = KUKA

GGGG = Feedback Device and Connectors
See table below

H= Internal Holding Brake
N = No Brake
B = Internal Holding Brake
      (Required for KUKA drive option)

M = Mounting Options 
N = None
T = Trunnion

N = Other Options 
N = None
A = Anti-Rotate Assembly, External
L = Limit Switch Housing / Anti-Rotate Assembly


1. Splined Rod (Internal Anti-Rotate) option reduces IP rating.


Drive Manufacturer

Code

Resolver

Encoder

ABB

AB

R3A4


Comau

CM

R4B1


Fanuc 64 Bit (Exlar Supplied)

FA


E2E6

Fanuc 64 Bit (Customer Supplied)

FA


E3E7

Fanuc 128 Bit (Exlar Supplied)

FA


E4F0

Fanuc 128 Bit (Customer Supplied)

FA


E5F0

Festo

FE

R1A1

S1A2

Kuka

KU

R5B1


Bosch (Indramat)

IN


S2D3


* Some options are not available with every configuration. For options or specials not listed above contact your local representative.

Anti-Rotate, External
This assembly restricts the actuator output rod from rotating when the load is not held by another method. Shorter actuators have a single anti-rotation mechanism; longer lengths have a mechanism on both sides.

Internal Anti-Rotate (Splined Rod)
A ball spline shafting main rod with a ball spline nut that replaces the standard front seal and bushing assembly. This rod restricts rotation without the need for an external mechanism. The rod diameter will be the closest metric equivalent to our standard rod sizes. Since this option is NOT sealed, it is not suitable for environments in which contaminants may enter the actuator.

Limit Switch Housing/ Anti-Rotate Assembly
External travel switches indicate travel to the controller and are adjustable for either the home or end position. Switches not included.

Product Specifications

GTW080 Performance SpecificationsOpen arrow

GTW080 Mechanical Specifications

MODEL CODE NOMINAL STROKE LENGTH MM (IN)* SCREW LEAD MM (IN) PEAK FORCE RATING N (LBF) CONTINUOUS FORCE RATING N (LBF) MAX VELOCITY MM/S (IN/S) DYNAMIC LOAD RATING N (LBF) ARMATURE INERTIA KG-M2 (IN-LB-S2)
GTW080-150-01 150 (5.9) 2.54 (0.1) 16,730 (3,762) 8,365 (1,881) 254 (10.0) 24,535 (5,516) 0.000369 (0.003267)
GTW080-150-02 150 (5.9) 5.08(0.2) 9,480 (2,132) 4,740 (1,066) 508 (20.0) 25,798 (5,800)
GTW080-150-05 150 (5.9) 12.7(0.5) 4,016 (902) 2,008 (451) 1,270 (50.0) 21,795 (4,900)
GTW080-300-01 300 (11.8) 2.54 (0.1) 16,730 (3,762) 8,365 (1,881) 254 (10.0) 24,535 (5,516) 0.000455 (0.004029)
GTW080-300-02 300 (11.8) 5.08  (0.2) 9,480 (2,132) 4,740 (1,066) 508 (20.0) 25,798 (5,800)
GTW080-300-05 300 (11.8) 12.7 (0.5) 4,016 (902) 2,008 (451) 1,270 (50.0) 21,795 (4,900)

*Full end to end stroke is 10 mm greater than nominal
Maximum velocities listed at maximum voltage (460 VAC) See Speed Force charts for speeds at various voltage levels
Continuous force rating based upon 25°C operation

 

GTW080 Electrical Specifications

MOTOR VOLTAGE   4 (AC)
Specifications subject to change without notice. Test data derived using NEMA recommended aluminum heatsink 10" x 10" x 1/4" at 25°C ambient. VAC class winding operational from 115 - 460 VAC. VDC Class winding operational from 24 - 48 VDC. Rotational speed linear proportional to input voltage
Max Bus Voltage V 460 Vrms
Speed @ Bus Voltage RPM 6000
RMS Sinusoidal Commutation
Continuous Motor Torque Nm 4.51
  lbf-in 39.9
Continuous Current Rating A 4.9
Peak Current Rating A 9.9
Torque Constant (Kt) (+/– 10% @ 25˚C) Nm/A 1.02
  lbf-in/A 9
Voltage Constant (Ke) (+/– 10% @ 25˚C) V/kRPM 61.6
0 - Peak Sinusoidal Commutation
Continuous Motor Torque Nm 4.51
  lbf-in 39.9
Continuous Current Rating A 6.9
Peak Current Rating A 13.8
Torque Constant (Kt) (+/– 10% @ 25˚C) Nm/A 0.72
  lbf-in/A 6.4
Voltage Constant (Ke) (+/– 10% @ 25˚C) V/kRPM 87.1
Pole Configuration Number of Poles 8
Resistance (L-L) (+/– 5% @ 25˚C) Ohms 2.5
Inductance (L-L)(+/– 15%) mH 17.3
Electrical Time Constant ms 6.8
Insulation Class 460 VAC Max, 180°C (Class H)
 

 

GTW080 Weights

GTW080 Weights  
Description kg (lb)
GTW080-150 5.2 (11.4)
GTW080-300 7.0 (15.4)
Brake Adder 1.1 (2.5)
Front Flange (1) 1.0 (2.2)
Tapped Face (3) 0.6 (1.2)
Rear Clevis (5) 0.4 (0.8)
Imperial Flange (F) 0.8 (1.8)
Imperial Clevis (C) 0.8 (1.7)
Anti Rotate (150 mm stroke) 0.6 (1.3)
Anti Rotate (300 mm stroke) 0.8 (1.8)
GTW080 Data CurvesOpen arrow
                                                             GTW080 - 0.1 inch lead
GTW080-0-1-in-lead-VAC.jpg




                                                              GTW080 - 0.2 inch lead

GTW080-0-2-in-lead-VAC.jpg



                                                              GTW080 - 0.5 inch lead
GTW080-0-5-in-lead-VAC.jpg
GTW100 Performance SpecificationsOpen arrow

GTW100 Mechanical Specifications

MODEL CODE NOMINAL STROKE LENGTH MM (IN)* SCREW LEAD MM (IN) PEAK FORCE RATING N (LBF) CONTINUOUS FORCE RATING N (LBF) MAX VELOCITY MM/S (IN/S) DYNAMIC LOAD RATING N (LBF) ARMATURE INERTIA KG-M2 (IN-LB-S2)
GTW100-150-01 150 (5.9) 2.54 (0.1) 30,784 (6,920) 15,392 (3,460) 191 (7.5) 54,557 (12,266) 0.0014085 (0.012467)
GTW100-150-02 150 (5.9) 5.08 (0.2) 24,196 (5,440) 12,098 (2,720) 381 (15.0) 55,972 (12,584)
GTW100-150-05 150 (5.9) 12.7 (0.5) 10,888 (2,448) 5,444 (1,224) 953 (37.5) 37,141 (8,350)
GTW100-300-01 150 (5.9) 2.54 (0.1) 30,784 (6,920) 15,392 (3,460) 191 (7.5) 54,557 (12,266) 0.0017399 (0.015399)
GTW100-300-02 300 (11.8) 5.08 (0.2) 24,196 (5,440) 12,098 (2,720) 381 (15.0) 55,972 (12,584)
GTW100-300-05 300 (11.8) 12.7 (0.5) 10,888 (2,448) 5,444 (1,224) 953 (37.5) 37,141 (8,350)
*Full end to end stroke is 10 mm greater than nominal
Maximum velocities listed at maximum voltage (460 VAC) See Speed Force charts for speeds at various voltage levels
Continuous force rating based upon 25°C operation

 


GTW100 Electrical Speficiations

MOTOR VOLTAGE   4 (AC)

Specifications subject to change without notice.
Test data derived using NEMA recommended aluminum heatsink 12" x 12" x 1/2" at 25°C ambient.
VAC Class winding operational compatible with drive voltages up to 460 VAC

* For actuators with a 0.1” lead, the torque and current must be limited to 8.89 nm/9.0 a not to exceed the continuous force rating specified in the mechanical specifications table on page 6. Peak torque and current values would be 2x the continuous values
**Rotational speed mechanically limited to 4500 RPM. Motor is theoretically
capable of achieving 6000 RPM at 460 Vrms.

Max Bus Voltage V 460 Vrms
Speed @ Bus Voltage RPM 4500**
RMS Sinusoidal Commutation
Continuous Motor Torque Nm 12.23
  lbf-in 108.2
Continuous Current Rating* A 12.3
Peak Current Rating* A 24.7
Torque Constant (Kt) (+/– 10% @ 25˚C) Nm/A 1.11
  lbf-in/A 9.8
Voltage Constant (Ke)
(+/– 10% @ 25˚C)
V/kRPM 67
0 - Peak Sinusoidal Commutation
Continuous Motor Torque Nm 12.23
  lbf-in 108.2
Continuous Current Rating A 17.4
Peak Current Rating A 34.9
Torque Constant (Kt)
(+/– 10% @ 25˚C)
Nm/A 0.78
  lbf-in/A 6.92
Voltage Constant (Ke) (+/– 10% @ 25˚C) V/kRPM 94.8
Pole Configuration Number of Poles 8
Resistance (L-L) (+/– 5% @ 25˚C) Ohms 0.65
Inductance (L-L)(+/– 15%) mH 4.6
Electrical Time Constant ms 7.1
Insulation Class 460 VAC Max, 180°C (Class H)
 


GTW100 Weights

Description kg (lb)
GTW100-150 13.1 (28.8)
GTW100-300 16.0 (35.2)
Brake Adder 1.2 (2.7)
Front Flange (1) 2.2 (4.7)
Tapped Face (3) 1.1 (2.4)
Rear Clevis (5) 0.8 (1.8)
Imperial Flange (F) 1.9 (4.1)
Imperial Clevis (C) 1.1 (2.5)
Anti Rotate (150 mm stroke) 1.5 (3.2)
Anti Rotate (300 mm stroke) 2.0 (4.5)
GTW100 Data CurvesOpen arrow
                                                             GTW100 - 0.1 inch lead
GTW100-0-1-in-lead-VAC.jpg



                                                              GTW100 - 0.2 inch lead
GTW100-0-2-in-lead-VAC-(1).jpg



                                                              GTW100 - 0.5 inch lead
GTW100-0-5-in-lead-VAC-(1).jpg
 

Product Literature

Catalogs and Brochures

Industrial - Exlar, Brochures/Catalogs
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This overview provides a brief summary of Exlar standard products available.
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Actuator Technical Data

Manuals and Technical Tips

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Exlar’s new T-LAM technology incorporated into the motor design provides a solution with 35% more motor torque.
Show Resources

Videos

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Our Automotive Factory Floor Solutions animation shows our FTX, GTX, GTW, and TTX actuators and where they can help factories worldwide.
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Our animation highlights the features and benefits of Exlar GTX Series Actuators.
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Exlar® actuators from Curtiss-Wright are an industry leader in electric actuation. Our research, pride, and creativity shine in this short video as we highlight our top product lines.
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Ever wonder about the benefits of changing your system from hydraulic cylinders to electric actuation. We have the information you need.
Show Resources

Find more resources in our InfoCenter

How can we help?

Can you please provide a cost comparison between a ball screw and a roller screw actuator?Arrow
Cost comparison of a roller screw to a ball screw is really a difficult subject, mainly because we have to take into account the differences in the pieces that we are comparing. A roller screw is typically going to be competitive to a ball screw in regards to price because we can oftentimes use a roller screw that is smaller in size compared to its “equivalent” ball screw. This is because of the significant life advantage roller screws have. Therefore, if you are using a smaller frame size roller screw and comparing that to a larger size ball screw, with similar life expectancies, your pricing is going to be very similar. Now depending on what your needs are, if you are looking for something with much greater life, we’re not necessarily comparing an equal product. So you may have to buy two ball screws in comparison to one roller screw. If you look at that from a value standpoint, you may pay more for a similar frame size roller screw but you may have to buy two ball screws in the same period of time that you would have to buy that one roller screw.
How do you calculate the maximum duty cycle allowed vs the amount on current/force applied?Arrow

Below is the maximum-allowable duty cycle for your application given the percentage of input current over the continuous current rating:

For example: If your actuator has a continuous current rating of 10 A and a continuous force rating of 1000 lbf, this means it will take about 10 A to produce 1000 lbf of force, or 5 A to produce 500 lbf of force, and so on. What if you need to push more than 1000 lbf? In most cases, you would look at a stronger stator or a larger actuator. What if it’s only for a few seconds? Could you over-work the current actuator? Well the answer is yes, and calculating by how much isn’t too difficult.

Let’s say you need to push 1500 lbf. This would be equivalent to 1.5x the continuous current rating of 10 A. If you look below, the graph recommends no more than a 22% duty cycle in this case. This means you can run the actuator 22% of the time at 15 A without overheating. The other 78% of the time, it needs to be off/cooling.

How long can you run at peak current?

Not a simple question, nor a simple answer. In reality, so many things affect this (how the system is built and how well the actuator is able to dissipate heat, are there additional heat sinks, particles in the air, degree of vacuum, new starting temp each time? (i.e. doesn’t always start from cold, etc.). Therefore, accurate times and temperature are quite difficult to estimate.

For example: At peak current (2x Continuous), the allowable duty cycle is 4%. That doesn’t mean you can run for 4 hours straight as long as you have 96 hours of off time in between however. From experience, a good rule of thumb we’ve estimated is 30s to a minute of peak current run time. Try to keep it under that, and then of course allow it to cool for the other 96% of the time.

How does a roller screw compare to a hydraulic actuator of equal size and rate force?Arrow
That is going to depend on the application, but with equivalent specifications and characteristics, a roller screw actuator will typically be very similar in size to (sometimes slightly larger than) a comparable hydraulic cylinder. Hydraulics are always going to have their place in the market once you get beyond 100,000 lbs. of force, but anywhere an electromechanical roller screw actuator fits the bill, size will be very similar.
How long until my specific actuator/application needs to be serviced/re-greased?Arrow

We are asked about re-lubrication intervals a lot. The reality is that there is no generic interval to re-lube actuators. It depends on so many things and every application and situation is different, it is nearly impossible to accurately calculate a re-lube interval per application. So instead, we have a rough guideline table (shown below) to give users an idea on when to start checking for old contaminated grease that needs to be replaced. However, since ambient temperature, heat dissipation, speed variation, particles in the air, etc. can vary so much from application to application, this is only a guideline. The actuator should be checked more frequently around the period this table suggests and once it is noticed that the grease is ready to be replaced (Dirty, contaminated / very dark, filled with particles / debris) – a re-lube interval can be determined.

Remember, grease needs to be cleaned out and replaced – don’t just insert more. (Except for FTX’s, those can handle 5-6 greasings before they need to be cleaned out)

RMS ROTATIONAL SPEED (RPM) RECOMMENDED GREASE RENEWAL PERIOD (HOURS)
250 10,000
500 10,000
1000 8000
1500 7000
2000 5800
2500 5000
3000 4000
What are the primary benefits of using an electric actuator system over hydraulics?Arrow
Electric actuators offer high speed and force, are flexible and easily programmable for a variety of load conditions, have high accuracy and repeatability, are efficient, simple to install, require little maintenance, and are environmentally friendly.

By not using a hydraulic system, the user can eliminate oil leaks, reduce pollution, and improve worker safety. Electric actuators are also a non-toxic solution, especially in the food industry
What is the accuracy of the actuator?Arrow

A very common question for us. For the actuator itself, that is easy. There is a mechanical lead accuracy of the screw, which is usually 0.001 in/ft, a typical specification for precision positioning screws of any type. This means that at any point over the cumulative length of the screw, the lead will vary by a maximum of 0.001 inches per foot of screw length. This is not the same as mechanical repeatability. The mechanical repeatability is a tolerance on how close to the same linear position the screw will return, if approaching from the same direction, and driven exactly the same number of turns. This value is approximately 0.0004 inches.

The electronic positioning resolution is a function of the feedback device and the servo amplifier. Let’s assume that we have Exlar’s standard encoder on a GSX30 with 0.2 inches per revolution lead on the roller screw. Exlar’s standard encoder has 2048 lines and 8192 electronic pulses per revolution that it outputs to the servo drive. So in a perfect world, the positioning resolution would be (0.2 in/rev)/ (8192 pulses/rev) or 0.0000244 inches. Anyone who has used servo drives knows that you can’t position to one encoder pulse. Let’s use 10 encoder pulses as a reasonable best positioning capability. This gives us a positioning resolution of 0.000244 inches.

More things to consider: When addressing repeatability and accuracy, several things must also be taken into account. One of these is the stiffness of the system. Stiffness is how much the system will stretch or compress under compressive or tensile forces. If the combination of the stiffness of the actuator and the stiffness of the mechanical system, including all couplings, mounting surface, etc. allows for more compression or stretch than the required positioning resolution of the system, obtaining acceptable positioning results will be nearly impossible. Another consideration is thermal expansion and contraction. Consider a GS actuator attached to a tool that is doing a precision grinding process. Assuming that the tool is steel and 12 inches long, a 5 degree rise in temperature will cause the tool to expand by 0.0006 inches. If the system is programmed to make 0.0002 inch moves, this expansion could cause serious positioning problems. The same applies to the components of the actuator itself. The actuator rod can change in temperature from a cold start up to running temperature. This change may need to be accounted for in very precise positioning applications.

What is the maintenance schedule life for a typical roller screw?Arrow
The maintenance schedule for any geared mechanical device, whether ball screw, roller screw, or gearhead, is going to be based on the amount of heat that is generated in the application, the amount of degradation of the grease, the type of grease being used, and the duty cycle. We provide some guidelines for our customers as starting points, but we recommend that for all new installations the lubrication be periodically inspected for presence and degradation as the best method for determining the right maintenance schedule for a given application. Having said that, we’ve seen repairs of units that have been in use for 15 years and when we’ve asked about grease renewal, they didn’t even realize that the unit could be serviced in the field. So we’ve had situations like that where they’ve gone for long periods of time with effectively no maintenance or no grease renewal. There are other applications that require grease renewal in very short intervals just due to the nature of the application.
What keeps the output shaft from rotating?Arrow
On a conventional roller screw design package, there typically is an anti-rotation groove designed into the housing, and a tab designed into the nut that rides in the housing groove as the actuator extends and retracts. In regards to the inverted roller screw design, part of the installation or the application requirement is going to be having that shaft solidly mounted a machine coupling or tooling on the machine otherwise providing some sort of external anti-rotation device on that output shaft. There are other ways of using splines and different types of non-circular output shafts that can allow for different types of spline nuts that will provide anti-rotation, but typically you’re going to see that mounted on the machine.
How do I estimate life of the actuator?Arrow
The L10 expected life of a roller screw linear actuator is expressed as the linear travel distance that 90% of properly maintained roller screws manufactured are expected to meet or exceed. This calculation should be used for estimation purposes only.

The underlying formula that defines this value is: Travel life in millions of inches, where:
Ca= Dynamic load rating (lbf)
Fcml= Cubic mean applied load (lbf)
ℓ = Roller screw lead (inches)

For additional details on calculating estimated service life, please refer www.cw-actuation.com.

L10=(Ca)3 x ℓ Fcm

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