The hydraulic pump drive shaft cannot bear radial force and axial force, so it is not allowed to directly install pulleys, gears and sprockets on the shaft end, and couplings are usually used to connect the drive shaft and the pump drive shaft. If due to manufacturing reasons, the coaxiality between the pump and the coupling exceeds the standard, and there are deviations during assembly, the centrifugal force will increase as the pump speed increases, and the coupling will deform, and the large deformation will increase the centrifugal force. A vicious circle is created, which results in vibration and noise, which affects the service life of the pump. In addition, there are other influencing factors such as the loose coupling pin and not being fastened in time, and the wear and tear of the rubber ring not being replaced in time.