Research On Vibration And Noise Reduction Of Axial Piston Pump Based On Structure Optimization Of Pump Housing

Because of the characteristics of large power and mass ratio, high reliability and flexibility, and good durability, hydraulic transmission as one of key techniques of modern transmission and control is greatly used in the conditions which need more than medium power output as well as convenient modulation and control of motion process.After the 1990s, the growing speed of hydraulic industrial decreased greatly, even the speed was negative sometimes. The main reason is some problems which belong to hydraulic system are hard to solve (oil leakage, large noise, low efficiency), also there are other strong rivals like electricity transmission, mechanical transmission and alternative current servo technique. The vibration and noise of hydraulic system (especially large power application condition) is paid more and more attention in hydraulic field. As a common sense, hydraulic pump is the main source of system vibration and noise.This thesis is based on "the Eleventh Five Years" Nation Science and Technique Support Plan "The Key Techniques Research of Industrialization High Characteristic Hydraulic Pump/Motor", analyzed some type of L10VSO31 serials swash plate axial piston pump, followed the latest achievement of reducing vibration and noise. Some research had been done about the structural vibration and noise control of the axial piston pump. The research results show: the method adopted in this project was one kind of feasible and right way to study the vibration and noise characteristic of the piston pump.The thesis is composed of five chapters which will be introduced as following:In the first chapter, the research state of the technique of reducing vibration and noise of the axial piston pump was overviewed, also the necessity of reducing vibration and noise of the axial piston pump as well as the significance and content of this project were introduced.In the second chapter, the shock excitation resources and excited frequency of the hydraulic pump were introduced first, then the vibration transmission routine and structural vibration response mechanism of the axial piston pump were analyzed. The control strategy of structural vibration was then clear. The noise produces mechanism of the axial piston pump was introduced, the surface noise radiation analysis had been done which made clear the control strategy of noise of the axial piston pump.In the third chapter, to further research the structural vibration and noise of the axial piston pump, the test rig of hydraulic system was also built. The noise and vibration of the piston pump was tested, the excited frequency was acquired through noise and vibration frequency spectrum of the piston pump as well as theory calculation. The main noise resource and vibration resource and the relative frequency of the piston pump were analyzed out.In the fourth chapter, the calculation modal analysis of the pump housing was done to acquire the nature frequency of the pump housing, the phenomenon of resonance was verified when the excited frequency was near to the nature frequency of the pump housing. To avoid resonance phenomenon, the structure of the pump housing was optimized. The optimized pump housing was also analyzed by calculation modal analysis utilizing the finite element analysis software ANSYS. The analysis results show the nature frequency of the optimized pump housing can stagger the excited frequency of the axial piston pump in some extend, which avoid resonance phenomenon and reduce structural vibration and noise.In the fifth chapter, the summary of the whole work and the prospect in the future are proposed.