DC torque motors are widely used in industries such as mechanical manufacturing, textiles, papermaking, rubber, plastics, metal wire, and cable manufacturing.

A DC torque motor is a special form of DC servo motor, mostly utilizing permanent magnet excitation. Its basic requirements are similar to those of DC servo motors. In order to achieve high output torque and low speed, they are generally designed with a flat structure. The ratio of the length of the motor armature core to its outer diameter is very small. To ensure stable operation, the motor's output torque must not exceed the maximum stall torque, also known as peak stall torque. The armature current corresponding to the peak stall torque is known as peak stall current. If the armature current exceeds the peak stall current, the motor will demagnetize and require re-magnetization to operate normally. To reduce torque and speed fluctuations, the stator is designed with multiple pairs of magnetic poles, and the armature is equipped with a greater number of slots, commutator segments, and series conductors. Torque ripple ΔM represents the variation in output torque at different positions of the armature.

DC torque motors adopt a large inner bore flat structure, which is advantageous for directly mounting the motor on the load shaft, improving the system's coupling stiffness. This enables the system to respond quickly, widen the bandwidth, operate stably, and meet dynamic performance requirements.

The motor constant KL is an important indicator of a torque motor, representing the ratio of peak stall torque to the square root of the input peak stall power (kgf·cm/W1/2). KL reflects not only the efficiency of the motor itself but also considers the power consumed by the motor.

The overall structure of a DC torque motor can be divided into two types: modular and assembled. The modular type consists of the stator, armature, and brush holder as the main components, with the user selecting the remaining supporting parts according to the installation requirements. The assembled type is similar to a conventional motor, with the motor forming a single independent unit.

To overcome the drawbacks of using brushes and commutators in DC torque motors, brushless DC torque motors were developed in the late 1970s. The principle and structure of brushless DC torque motors are similar to brushless DC motors.