An Approach to Predict Wear Distribution of Valve Plate in Elasto-Hydrodynamic Lubrication

The leakage flow is the vital index judging axial piston pumps, which is strongly influenced by the wear resulting from the cylinder block tipping against the valve plate. In order to improve the energy efficiency and realize the reliable design of axial piston pumps, this paper presents an integrated model to predict the cylinder block/valve plate interface performance, numerically solving Reynolds equation coupled with the elasto-hydrodynamic deformations, the pressure-viscosity effect, and the asperity contacts. The film thickness distribution in steady state is numerically calculated, then the wear distribution under different kinds of operating conditions can be predicted based on the Archard wear equation. The analytical results indicate that the wear appears at both sides of the inner dead point, which is verified through measuring results. The proposed approach shows an essential prediction on the wear distribution.