Gear coupling is a common mechanical part used to transmit torque in gear reducer. It is composed of two parts, the driving shaft and the driven shaft. Most of the general power machine is connected with the working machine. The radial size is small and the carrying capacity is large. It is often used for shafting transmission under low-speed and heavy-duty working conditions. The gear coupling with high precision and dynamic balance can be used for high-speed transmission, such as the shafting transmission of gas turbines.