Glossary · Motion control and drives
Torque motor
Also known as: Direct-drive rotary motor, Frameless torque motor
German: Torquemotor
In motion control, a torque motor is a permanent-magnet synchronous motor with a large diameter and many poles, designed to deliver high torque at low speed so that it can drive a load directly without a gearbox.
- Motion control
In one sentence
A torque motor is a many-pole PMSM built for high torque at low speed, driving loads directly without a gearbox.
Example
A rotary table in a machine tool uses a torque motor and a high-resolution angle encoder for backlash-free positioning.
How it applies
- Engineering: Torque motors are often supplied as frameless kits (stator and rotor) built into the machine structure. Cooling and bearing design become the machine builder's task.
- Commissioning: High-resolution encoders and careful loop tuning are needed; the direct coupling makes structural resonances visible.
- Maintenance: Strong magnets require special handling during installation and removal.
- Documentation: Include assembly instructions for built-in motors with the magnet-related warnings, and document cooling requirements and temperature monitoring.
Torque motor vs. servo motor
A standard Servo motor runs at higher speed and is usually combined with a gearbox. A torque motor delivers the required torque directly at low speed.
Temperature sensors in the winding are usually evaluated by the drive; describe the resulting warnings and trips in the fault list.