Pre-compression Angle of Water Hydraulic Axial Piston Pump

To investigate the flow characteristics of the water hydraulic axial piston pump,the mathematical model of the flow distribution characteristic of the port plate was established in this study,which considers the pre-compression angle of the port plate,the leakage flow through the piston/cylinder gap and the port plate/valve plate gap.The structure parameters of the port plate were optimally calculated.The dynamic simulation on the flow field of the water hydraulic axial piston pump with different sizes of pre-compression angle were implemented using PumpLinx software,and the influences on the properties of flow distribution for each size of pre-compression angle were investigated.Simulation results show that the fluid in the discharge chamber can flow into the piston chamber reversely during the pump working in the discharge period.The rate of reverse flow in the piston chamber directly relates to the flow ripples and pressure ripples of the pump.When the pre-compression angle is improved,the reverse flow,flow ripple and pressure pulsation in the piston chamber can be reduced,therefore,the flow characteristics of the pump increase.When the pre-compression angle is set to be 20°,the best result can be obtained.If the pre-compression angle exceeds 20°,a higher flow ripple is obtained because of the superposition of the reverse flow.