The Cavitation Mechanism And Structural Parameters Optimization Of Valve Plate Pairs For Large Displacement Axial Piston Pump

Axial piston pump due to the power density,variable easily,high efficiency,long life and other advantages of a wide range of applications in the hydraulic system.In recent years,the axial piston pump toward high pressure,high flow,low noise direction.Pump pressure and material development is closely related.As the displacement increases,the pressure at the suction port of the piston pump will decrease,the pressure at the oil discharge port will increase,the pressure difference will increase,and the valve plate as the core component of the large-displacement axial piston pump will be high and low pressure oil exchange.Areas are more likely to generate cavitation.In the working process of the piston pump,if the oil pressure is lower than the saturated vapor pressure of the oil,the oil will precipitate gas,and with the flow of oil,when the bubble moves to the high pressure area,the external pressure suddenly rises,the pressure inside and outside the bubble is not Equivalence will be broken.If such a bubble burst occurs on the surface of the part,cavitation will occur,causing damage to the part and thus affecting the working efficiency and service life of the piston pump.This paper aims to reduce the cavitation damage of the valve plate and increase the service life of the piston pump.The theoretical analysis and the CFD flow field simulation analysis method are used for the cavitation erosion of the surface of the Rexroth large-displacement axial piston pump plate.The phenomenon was studied.The working principle of the axial piston pump and the reasons for the cavitation are analyzed.The dynamic analysis of the piston is performed.The working principle of the existing valve plate is analyzed in detail.The reason why the large displacement axial piston pump is easy to generate cavitation is analyzed.Considering the characteristics of the oil film,based on the cavitation mechanism analysis and the working parameters of the piston pump,a physical model is established.;By calculating the Reynolds number in the fluid region of the piston pump,the fluid state in the piston pump is obtained,and the turbulence model in the Fluent simulation is determined.In the simulation,the phase change rate between the gas and the liquid is considered,and the Full Cavitation Model is selected.Divide the piston pump fluid domain into three parts,use the ICEM software parameter control and grid assembly to mesh the model;write the UDF program to control the piston movement,and use the dynamic grid and sliding grid in Fluent.Technology,simulate piston motion,set boundary conditions for simulation analysis;The cavitation degree of the piston pump under different speeds and loads was analyzed,and the influence of the width and depth of the triangular groove on the cavitation under specific conditions was analyzed.Finally,based on the response surface method,the triangular groove was The width and depth angles are considered as factors.The gas volume fraction is optimized as the response value(optimization target),and the triangular groove structure parameters with the smallest gas volume content are obtained,thereby optimizing the anti-cavitation structural parameters of the valve plate.