Abstract:In order to solve the problem of insufficient oilabsorption of hydraulic pump, an auxiliary oilabsorption device based on the jetflow principle was designed. By using CFD software,threedimensional numerical models of piston pump with or without this device were established. The oilabsorption characteristics of piston pump under different inlet pressure and gas content were analyzed.The result shows that the lower the inlet pressure, or the higher the gas content, the more severe the cavitation, then the elastic modulus of oil is lower, which increased the time of the piston chamber pressure arising to working pressure during the stage of oil back flushing and made oil back flushing more severe, so the oilabsorption performance of pump is worse. If a device was added, the flow through the device is a pressurized process,which can suppress the above phenomenon and the oilabsorption performance of pump is improved. From the simulation results, the device has a good effect of auxiliary oilabsorption, and the worse the oilabsorption performance of pump, the better the effect.