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Using a Torque Motor for Winding and Unwinding Type Applicat

Posted: Mon Mar 14, 2011 1:53 pm
by om_tech_support_JT
A torque motor is an excellent product for winding and unwinding type applications. Due to the design of the motor, it reaches full torque at 0 output speed, or locked rotor condition. A torque motor can act as a brake when back driven, or a simple device to provide tension. Depending on the torque setting, the motor will provide tension to the material while taking up slack in the line automatically, essentially matching the line speed.

The TMP-1 power controller can be used to adjust the torque setting by changing the voltage going to the motor. It can be set via onboard potentiometers, external potentiometers, and external DC voltage. The user can simply set the torque to the required level and the motor will automatically match the line speed due to its natural characteristics.

When referring to the torque-speed chart below, you will see that higher voltages will increase the motor torque and lower voltages will decrease the torque. As the torque decreases, the effective motor speed will naturally decrease as well. The torque level should be adjusted so that the generated torque will not break the material being wound.

This way, any slack in the system is automatically taken up and tensioned properly. If the motor is run at 60 VAC or less (half the rated voltage), the torque motor carries a continuous duty cycle rating.

....For more details and an application specific example, please view the HTML version of the article here: ... tions.html

Re: Using a Torque Motor for Winding and Unwinding Type Applicat

Posted: Thu May 02, 2013 11:21 pm
by max2tall
Hi, I see this is an old post, but it is just what I'm looking into now. (btw the link in your post is broken)

The tmp-1 appears to do exactly what I need, but the motors it pairs with are all too low torque for my application.

I'm looking for up to 5Nm torque from the motor in a reverse braking / holding situation (variable via the control)

no gearing is wanted. I'm prototyping to test an idea for a physiotherapy device, patient pulls cable that 'feels' like a weight to him, which I can vary and measure.

We are 240v 1ph, & basically want to build this: ... -Demo.html

but with higher torque available for stronger pull force.


Re: Using a Torque Motor for Winding and Unwinding Type Applicat

Posted: Fri May 03, 2013 11:36 am
by om_tech_support_JT

Sorry about the broken link. Here is the technical article regarding torque motors and an application example: ... tions.html

If you need the ability to control more torque than what's offered by our torque motors, perhaps you should look into our NX series auto-tuning servo motor systems. With the NX series servo motor systems, we can offer up to 1 horsepower of power. There are 4 control modes which can be selected: speed control mode, position control mode, torque control mode, and tension control mode. In torque control mode, the NX series operates like our torque motors. In tension control mode, applications such as winding a roll of film from a feed reel to a take up reel can be easily performed without using a tension detector or additional control equipment. You simply input data about your setup (such as initial and final diameters), then it will internally calculate and automatically adjust its torque on the fly to keep the same tension. Internal parameters and extended functions of the NX driver can be accessed/programmed with the optional OPX-2A hand-held control module, or the MEXE02 data software.

For more details regarding our NX series servo motor and gearmotor systems, please click the link below: ... index.html

Re: Using a Torque Motor for Winding and Unwinding Type Applicat

Posted: Fri May 03, 2013 9:14 pm
by max2tall
Hi, Thanks for that info.

Problem is the servo solutions are complicated & expensive compared to the simplicity & cheapness of the tmp-1.

We don't need high rpm's etc. - will be 3 states of operation: being pulled against, reeling in, or in a locked rotor torque condition.

So a low speed high torque motor is needed.

can the tmp-1 be used with an amplifier for greater currents to other torque motors?, or can it be used directly with other larger diameter torque motors of the same type as the 'compatible' ones in your list?

thanks :)

Re: Using a Torque Motor for Winding and Unwinding Type Applicat

Posted: Mon May 06, 2013 3:51 pm
by om_tech_support_JT
You are correct. Servo motor systems are more expensive than torque motor systems because they have the added benefits of a high resolution encoder feedback plus more complex circuits in the driver to deal with PID loops. The results are better performance, faster speeds, and more functions.

One example: since reel to reel (feed and take up) applications always have changing diameters, the torque of the motor needs to be adjusted continuously in order to keep the same tension force. If you use a torque motor and a TMP-1 controller, another device is needed to sense the changing diameters and vary the torque of the motor. With our NX series servo motor systems, we can do this without any additional device. You can simply input your initial and final diameters and inertias, then it will automatically calculate and keep the same tension.

Unfortunately, our torque motors only go up to 20W. Oriental Motor Japan offers a 40W torque motor but it's rated @ 100VAC. If you need more torque, but do not want a major upgrade to a servo system, we can offer the BX series brushless motor systems or AR series stepper motor systems. Both systems have "extended functions" which can be accessed with an optional device. The AR series uses the data setting module (OPX-2A) or data edit software (MEXE02). The BX series extended functions can only be access through the data setting module (OPX-1A). Torque-limiting is one of the "extended functions".

The differences between the torque-limiting functions of these systems (NX series, BX series, and AR series) is its control accuracy. The NX series can control tension at about +/-5%. The AR series can control torque at about +/-10%. The BX series and other brushless motor systems such as BLE series and BLV series can control torque at about +/-20%.

Here are the PRODUCT OVERVIEW links:



The TMP-1 controller was designed to only work with our torque motors so we have no test data with other manufacturer's motors. We cannot guarantee its performance with other motors.