Investigation of the Pressure Fluctuation of Piston Chambers with Variable Slot Geometry

High-pressure fluctuation and flow ripple may cause unexpected vibration and noise when the piston pump works under severe conditions, and eventually lead to hydraulic transmission failure. The geometry of the valve plate has a great influence on the pressure fluctuation of the piston chamber. In order to optimize the structure of the valve plate, a mathematical model considering the slot geometry and the flow leakage of the lubricating interfaces was established in this paper. The model was used to investigate the pressure of the piston chamber, and then the accuracy of the model was validated by comparing simulation and experimental results. Further simulation results show that the pressure fluctuation in the piston chamber can be effectively suppressed by optimizing the triangular slots parameter of the valve plate, and a good design of the slot geometry could reduce the undershoot and overshoot of the pressure in piston chamber at the starting moment.