What is the difference between a torque motor and a servo motor?
A question often asked is what the difference is between a servomotor and a torque motor. When it comes to comparing a torque motor to a servomotor, it is important to remember that there is no such thing as a perfect solution. Both motors are used throughout many industries for many different applications. They are both very efficient motors. So when making a decision between a torque motor and a servomotor, the most important parameters are speed and acceleration.
What is a servomotor?
Servomotors encompass a wide range of motor types, but most commonly, they refer to a permanent magnet synchronous motor (PMSM), equipped with a closed-loop control mechanism. These servomotors generally feature a long axis, small diameter, and an output shaft. They are often paired with a gearbox to achieve the desired speed-to-torque ratio. Typically, they have a NEMA-style mounting for easy integration into various applications. For clarity, we will refer to these motors as “conventional servomotors.”
What is a torque motor?
Torque motors are also PMSMs that can be equipped with closed-loop control mechanisms, similar to conventional servomotors. However, their design and shape differ significantly. A torque motor is typically toroid-shaped, resembling a donut, with a large diameter and short axis. This unique shape allows torque motors to generate high torque but at a limited RPM. Unlike conventional servomotors, torque motors often do not require a gearbox, resulting in higher efficiency and accuracy.
In short what is a servo motor/torque motor
- Servo motors: Higher speed, less torque, often used with a gearbox to achieve the desired torque.
- Torque Motors: High torque, low speed, direct drive without gearbox, higher efficiency and accuracy.
Conventional Servo motor
Torque motor (stator and rotor)
Key differences between a torque motor and a servo motor?
To give a quick and simple answer: there doesn’t have to be a difference. Both torque motors and servomotors can be equipped with sensors (like encoders) to provide feedback signals for closed-loop control. This feedback allows precise control over position, acceleration, and velocity, technically making a torque motor a type of servomotor when equipped with these features.
Some key differences between a torque motor and servo motors are:
Shape and Design: Servomotors: Long axis, small diameter, often with an output shaft. / Torque Motors: Large diameter, short axis, toroid-shaped.
Performance: Servomotors: Capable of high RPM but generate less torque. Typically used with gearboxes to achieve the required torque, although this can reduce efficiency and accuracy. / Torque Motors: Generate high torque at low RPM, ideal for direct drive applications without the need for a gearbox, maintaining high efficiency and accuracy.
Applications: Servomotors: Commonly used in applications requiring precise control of position, speed, and acceleration, such as CNC machines, robotics, and automated manufacturing systems. / Torque Motors: Suitable for applications needing high torque at low speeds, such as direct drive systems in machine tools, robotic joints, and rotary tables.
Conclusion torque motor vs servo motor
In summary, the choice between a torque motor and a servomotor largely depends on the specific application requirements. Torque motors excel in applications requiring high torque at low speeds without the need for a gearbox, offering greater efficiency and accuracy. On the other hand, servomotors are better suited for applications demanding higher speeds and precise control, often using gearboxes to meet torque requirements.
Understanding the distinct characteristics and advantages of each motor type will help in selecting the right motor for your specific needs, ensuring optimal performance and efficiency in your application.
Video: Servo vs Torque Motor
Which one to choose?
- For some applications, like indexing tables, torque motors are mainly used because of its higher accuracy.
- For high RPM, low torque applications, mainly conventional servomotors are used because they can reach the desired speeds.
- Conventional servomotors can be fitted with different gearboxes, making it relatively easy to generate the desired speed to torque ratio’s, using available motor designs.
- But when an existing torquemotor design is fitted to your application it often outperforms conventional servomotors. So the best solution depends on the application and what is already available on the market.
- For other applications both types of motors can be used and it is usually a matter of the best price-performance ratio.
Get in contact with
the support team
If you would like to receive a quotation, have a question about our products, or want to know what we can do for you specifically. You can fill in our contact form. We will get back to you within 24 hours.
