Simulation research on distribution method of axial piston pump utilizing pressure equalization mechanism

Noise reduction in axial piston pumps has been attempted by many researchers with different design approaches and techniques. However, most traditional structures on valve plate for noise reduction are at the cost of efficiency to different extent. In this article, a new distribution method with pressure equalization mechanism composed of check valve and pressure recuperation chamber is discussed. A simulation model for the analysis of noise excitation sources is developed, and is verified by comparison of flow ripple between simulation and experiment. The working principle of pressure equalization mechanism is analyzed in detail. Compared with reference commercial axial piston pump, the simulation results indicate that the flow ripple and the torque pulsation are sharply reduced with the pressure equalization mechanism. Moreover, the volumetric efficiency of axial piston pump is also improved. The power of variabledisplacement control mechanism will be reduced and the control accuracy can be improved easily due to the swash-plate torque reduction. The analysis shows that the check-valve frequency and the pressure recuperation chamber volume are vital for the pressure equalization mechanism. The optimal pressure recuperation chamber volume is about three times the size of the minimum piston chamber dead volume. The optimal maximum displacement of check valve is about 1 mm. The pressure equalization mechanism is promising in the design of high-performance axial piston pump with low noise emission.