Shaft couplings are mechanical parts used to connect two shafts (driving shaft and driven shaft) in different mechanisms to rotate together to transmit torque. In high-speed and heavy-duty power transmission, some couplings also have the functions of buffering, damping and improving the dynamic performance of the shafting. The coupling consists of two halves, which are respectively connected with the driving shaft and the driven shaft. Most of the general power machines are connected with the working machine by means of couplings.