A coupling is a mechanical component used to firmly connect the active and passive shafts in different mechanisms for rotation, and transmit motion and torque.

The application range of couplings is very wide, including automobiles, lathes, milling machines, fans, water pumps, machine tools, testing benches, printing equipment, printing equipment, extruders, etc. Couplings can be classified into heavy, medium, small, and light types based on the magnitude of the transmitted torque in practical applications, with different application scenarios. Couplings can transmit power, compensate for axial errors, change speed and torque, isolate vibration, and facilitate maintenance.