Torque Motors

Torque motors are a specialised form of brushless permanent-magnet synchronous motor. They are able to operate indefinitely when stalled without incurring any damage to the motor. Instead, the motor will continue to supply a steady torque. They are induction motors with wide diameters which allow high levels of torque. Their thermal performance allows their continued operation while drawing a high current in their stalled state. They are also called 'frameless' motors as they do not possess housing, bearings or feedback. Torque motors can differ in their internal configuration. The complete torque motor has its rotor connected to the machine shaft while the built-in torque motor has its stator and rotor supplied as individual components. Torque motors are available as a linear version which has a 'rolled-up' motor. The other version is a servo drive with a large number of poles. Torque motors are found in a large number of appliances. The linear torque motor is installed in fridge compressors and air conditioning. They are also the actuators in direct drive mechanisms and in the force feedback steering wheels of some computer games. The throttle control of internal combustion engines are torque motors.