A torque motor is a directdrive motor — usually of relatively large format — that applies torque at rpm down to zero. See http://www.motioncontroltips.com/?s=d... for more on this. Torque motors run indefinitely and apply torque even if the load on the rotor reaches a level that locks the rotor — without sustaining damage. In such instances, the motor will apply a steady torque to the load. Some in industry liken the torque motors to their linear directdrive cousins — linear motors. (Sometimes called force motors, these abound in specialty applications.) Also visit http://www.motioncontroltips.com/cate... for more on one common application for torque motors — that of directdrive rotary tables.