A worm gear reducer is a power transmission mechanism that uses a gear speed converter to reduce the rotational speed of an electric motor to the desired speed, while generating a relatively large torque. Among the mechanisms used for power and motion transmission at present, reducers have a very wide range of applications.

The basic structure of a worm gear reducer is mainly composed of transmission parts (worm and worm gear), shafts, bearings, a housing and its accessories. It can be divided into three basic structural parts: the housing, the worm and worm gear, and the bearing-shaft assembly. The housing is the base for all accessories in the worm gear reducer, and it is an important accessory that supports and fixes the shaft system components, ensures the correct relative position of the transmission accessories, and bears the loads acting on the reducer. The main function of the worm and worm gear is to transmit motion and power between two staggered shafts, and the main functions of the bearings and shafts are power transmission, operation and efficiency improvement.

In the transmission mode of the worm gear reducer, the worm gear transmission has characteristics not found in other gear transmissions, that is, the worm can easily rotate the worm gear, but the worm gear cannot rotate the worm. This is because the structure and transmission of the worm and worm gear are realized through friction. The self-locking function of the worm gear transmission mode of the worm gear reducer is very useful in mechanical applications, such as winches, conveying equipment and so on. The transmission mode of the worm gear reducer belongs to worm transmission, which is equivalent to screw transmission. Precisely because of this transmission mode, when the worm gear reducer reaches a certain speed ratio and the lead angle of the worm is smaller than the equivalent friction angle between the meshing gear teeth, the mechanism has self-locking performance and can realize reverse self-locking, that is, only the worm can drive the worm gear, and the worm gear cannot drive the worm.