Abstract: Taking the closed swash plate axial piston variable displacement pump with a port plate with positive opening and double damping grooves as the research object, the homogeneous multiphase transport equation, standard k-ε turbulence model and full cavitation model are used to study the time-space dynamic evolution process of cavitation flow field on the surface of port pair of piston pump considering the compressibility of medium. It is found that the location and extent of cavitation erosion on the surface of cylinder block are highly correlated with the location, duration and severity of cavitation on the surface of valve pair during the transition process of valve distribution. The main cause of cavitation damage on the valve surface of the cylinder block is the high pressure difference between the piston cavity and the oil suction cavity caused by the positive opening of the valve plate. The cavitation damage on the leading edge and the trailing edge of the cylinder block spacer is respectively related to the transient process of pressure rise and pressure relief of the piston cavity.

Key words: closed swash plate axial piston pump, underlap valve plate, damping groove, cavitation erosion, numerical analysis