Optimization Design For Noise Reduction Of Axial Piston Pumps Based On Vibro-acoustic SimulationModel

Axial piston pumps have been used in many fields due to the advantages of large power-to-weight ratio,high working pressure level,and multiple variable modes.However,in the entire hydraulic system,the noise level of the axial piston pump is relatively high,and the vibration and noise generated during operation will cause problems such as increased wear and tear of parts,reduced service life,and increased noise pollution in the working environment.Therefore,this paper developed the optimization design for noise reduction of the axial piston pump based on vibro-acoustic simulation model.Firstly,based on the structure and working principle of the axial piston pump,its noise generation mechanism was summarized,and its structural noise excitation force was analyzed.The mechanical-hydraulic integrated co-simulation model was constructed,and the chamber pressure was obtained through the model,so that the excitation force in the frequency domain was calculated and analyzed.Secondly,an assembly model of the axial piston pump containing internal components was constructed to solve the vibration response.In order to ensure the accuracy of the finite element model,the modal test of the parts and the vibration test of the pump were carried out.The frequency error between the simulated and experimental modal frequencies obtained from the modal test was within 5%.Although the vibration velocity amplitude-frequency diagram of measuring point 3 obtained from the vibration test was slightly smaller than the simulated value as a whole,the trend was in good agreement.Then,the required vibration velocity was mapped to the acoustic boundary element grid to solve the radiation noise,and a method for identifying the noise reduction area of the pump shell was proposed.Sound source localization experiments was performed to determine that the main noise source was located on the left side of the pump,and demonstrated each other with the analysis results of vibration and noise characteristics.According to the analysis results of the radiation noise,the noise reduction field point was selected,and the acoustic transfer vector,modal and panel acoustic contribution of the axial piston pump were analyzed.Taking the radiated noise at 1350 Hz at field point 3 as the noise reduction target,the acoustic contribution of panel 2 reached 46.1%,which was the panel with the largest contribution to the total sound pressure,provided theoretical guidance for the structural optimization design of axial piston pump shell with low noise as the goal.Finally,the multi-objective structure optimization of the valve plate of the axial piston pump was carried out.Taking the noise excitation source as the optimization target,genetic algorithm was used to optimize the width angle and depth angle of the triangular damping groove of valve plate.Through the analysis of the contribution of the excitation force,it was found that the Y-direction moment at the peak of the noise sound pressure level(1350Hz)had the largest contribution to the total sound pressure.Therefore,the final optimization plan P1 and N2 were selected from the two sets of pareto solutions.The optimization effect was verified through the vibro-acoustic simulation model.The results showed that the optimization effect of plan P1 was better than plan N2,and the sound pressure level of optimization plan P1 at field point 3 was reduced by 2.49dB(A)at 1350Hz,which verified the effectiveness of the optimization method.