The Source Of Swash Plate Axial Piston Pump Fluid Vibration Research

As the appliance of the hydraulic system in the high-technical field develops, the request of the reliability and environmental adaptation for the hydraulic system increases. But the vibration and noise caused by the hydraulic pump influences the reliability of the hydraulic system, including three forms of vibration followed by mechanical vibration, fluid vibration and vibration caused by cavitation among which the fluid vibration is caused by the flow fluctuation and the pressure impact led by the flow allocation. Therefore, to decrease the vibration caused by the optimizable structure through analyzing causes of the flow vibration has theoretical and practical effects on reducing vibration and noise.This paper studied the turbulent flow model, the flow fluctuation characteristics, the harmonic response and transient response of the axial piston pump and the best flow allocating method, combining the theory analysis and experimental research, based on the vibration transmission theory and the oil strike theory of the piston cavity.Through analyzing the turbulent flow model, the simulation accuracy was improved by modifying model coefficients which were obtained by comparing different turbulent models under the multi-coefficient including the vertex shape, the flow rate and the pressure in the mechanism model and the PIV testing equipment of the single piston-valve-plate structure.The flow fluctuation characteristics included the flow rate and pressure fluctuation of the axial piston pump and the piston cavity, which were obtained by analyzing the transient flow with the modified turbulent finite volume model of the axial piston pump, considering the oil compressibility and using the dynamic mesh and the sliding mesh, and providing the theoretical basic for the transient response analysis.The harmonic response and transient response analysis of the axial piston pump included two sides of work, as follows, one was to get the natural frequency of the axial piston pump under the factual boundary condition through harmonic response analysis and the vibration distribution of the axial piston pump under the flow fluctuation excitation through the transient response analysis.Through studying the best flow allocating method, the optimized flow allocating structure was put forward by analyzing the flow allocating characteristics of the triangle damping groove, and the optimizing method was proofed correct by analyzing the forward and afterward flow characteristics. Analysis of the effect of flow and pressure characteristics under the different plunger damping hole diameter and the oil film thickness of sliding shoe.Verify the simulating transient response result by analyzing the vibration of the axial piston pump under different rotation speed and different load pressure through the hammering method on the vibration experimental platform.