A special form of DC servo motor. Most of them use permanent magnet excitation. The basic requirements are similar to DC servo motors. In order to obtain a large output torque and a low rotational speed, a flat structure is generally formed.
The working principle of the DC torque motor is the same as that of the ordinary DC servo motor, except that the ratio of the structure and the external dimensions is different. In general, DC servo motors are mostly made into an elongated cylindrical shape in order to reduce their moment of inertia. In order to generate relatively large torque and low rotational speed under the same volume and armature voltage, the DC torque motor is generally disc-shaped, and the ratio of armature length to diameter is generally about 0.2; Considering that it is generally made of permanent magnet multipole. In order to reduce the fluctuation of torque and speed, more slots, number of commutators and number of series conductors are selected.
The overall structure type is divided into two types: split type and built-in type. The split type structure includes three parts: stator, rotor and brush holder. The casing and the shaft are selected by the user according to the installation method. The built-in type is the same as the general motor. The shell and shaft have been assembled by the manufacturer.