Couplings are also known as couplings. A mechanical component used to firmly connect the driving shaft and driven shaft in different mechanisms and rotate together and transmit motion and torque. It is also sometimes used to connect shafts to other parts (e.g. gears, pulleys, etc.). It is often composed of two halves, which are connected by keys or tight fits, fastened at the ends of the two shafts, and then connected in some way. The coupling can also compensate for the deviation (including axial offset, radial offset, angular offset or comprehensive offset) between the two shafts due to inaccurate manufacturing and installation, deformation or thermal expansion during operation; and shock mitigation and vibration absorption.