Noise Analysis Of Case Oil Absorption Double-end-face Distribution Axial Piston Pump

With the increasing requirements of pump performance and life for hydraulic system,the noise problem of axial piston pumps under high pressure and large flow conditions has become increasingly prominent,which seriously hindered the development of axial piston pumps.The material strength and toughness of the pump are improved,reducing the damage caused by mechanical vibration at large flow,but the noise caused by the increase of flow rate is not significantly improved.The generation of fluid noise is highly correlated with the flow field of the hydraulic oil in the plunger pump.Therefore,the improvement of the flow channel of the hydraulic oil in the axial plunger pump is of great significance to reduce the fluid noise in the pump.Based on the research of the open-circuit axial piston pump,this paper improves the structure of the existing swash plate type axial piston pump,completes the design of the case oil absorption double-end-face distribution axial piston pump,and focuses on the plunger damping of the traditional piston pump.The hole and the oil inlet method have been improved to reduce the flow rate of the oil inlet,thereby reducing the noise generated by the hydraulic oil due to the high-speed flow.This paper mainly studies the fluid vibration mechanism and transmission method of the pump and noise radiation.The main research contents are as follows:(1)The design the plunger group and swash plate damping groove of the case oil absorption double-end-face distribution axial piston pump.Based on the flow characteristics modeling and analysis method of piston pump,the leakage flow of the three friction pairs of the pump is analyzed.(2)Determine the excitation source of mechanical vibration and fluid vibration,and established a single plunger pressure pulsation model on the pressure oil side.The flow field in the pump shell on the suction side was simulated by finite element method on Ansys,and the fluid exciting source in the pump shell was determined.(3)Since the vibration generated by the fluid excitation source needs to be transmitted to the surface of the pump casing through the mechanical structure and generate noise,it combines the structural characteristics of the case oil absorption double-end-face distribution axial piston pump to discretize the continuous mechanical structure into a vibration unit,the continuous mechanical structure is discretized into vibration Unit to built a vibration physical model.Parameters such as elastic modulus and mass of mass for each discretized vibration unit are calculated with the help of Ansys simulation.The axial and radial vibration systems of case oil absorption double-end-face distribution axial piston pump are built by Amesim software,and the vibration power and noise intensity of each vibration radiation surface are obtained.(4)The sound intensity levels before and after the improvement of the plunger pump are analyzed and compared through experiments to verify the accuracy of the theoretical calculation and the rationality of the structure of the case oil absorption double-end-face distribution axial piston pump,which provides the basis for further optimization of the case oil absorption double-end-face distribution axial piston pump.