Experimental and numerical studies on erosion damage in damping holes on the valve plate of an axial piston pump

Abstract

Erosion damage affects the reliability and durability of axial piston pumps. An axial piston pump was tested using endurance life testing method. The phenomenon of erosion damage on the valve plate was observed using a confocal laser scanning microscope, by comparing the surface on the valve plate before and after the endurance life testing. A CFD turbulence model inclusive of the cavitation effects was developed to predict the flow physics. The flow physics in the axial piston pump were presented and analyzed, including the fluid velocities, velocity fields, the total volume fraction fields of gas and vapor, and pressure fields. Two causes of erosion damage were found, the appearances of large amount of vapor, and directly hitting by the jetting flow. The first one is the cause of erosion damage on the surface near the transition region from the inlet port to the outlet port, and the second one is the cause of erosion damage on the surface near the transition region from the outlet port to the inlet port. Besides, the findings show that the fluid velocities closely relate to the area of erosion damage. The study provides insights into the occurrence of erosion damage in axial piston pumps.