The Research on the Fault Mechanism of Port Plate/Cylinder Block Frictional Pair in Axial Piston Pump

The problem of vibration and noise in axial piston pump has been intensively studied in the past; however, recently the interest about this problem grew because of great requirement for designing excellent performance axial piston pump having high pressure, high rotating speed and high flow characteristics etc. One of the most important noise and vibration sources is the flow distribution noise caused by the shock pressure of flow distribution and cavitations in the process of the regulation of working conditions, and the vibration caused by wearing of the port plate frictional pair. A lot of methods have been developed to reduce the flow distribution impulsion and the port plate wearing by improving the design of port plate as well as the materials of axial piston pump. However, the current research level remains incomplete and there are still noise and vibration existing in the axial piston pump. So it is very important to develop efficient diagnosis methods for online monitoring the hydraulic pump which helps to increase the reliability of the whole fluid power system. In the present paper the structure and working principle of port plate in axial piston pump is discussed first. Then this paper proposes a fault diagnosis method based on vibration signals after analyzing the fault mechanism of the port plate frictional pair. And it verifies the diagnosis method through experiment and gives out the analysis result. The result indicates that the vibration signal is sensitive to the port plate frictional pair’s wearing fault.