Research On Noise Radiation Of Electrical Vehical Reducer Housing

With the fast development of new-energy vehicle industry, the electric car have been received extensive attention in most automobile plant. Due to the different powertrain structure of pure electric and traditional vehicles, there are significant differences in vehicle noise excitation source. For pure electric vehicles, the impact of vehicle NVH performance is mainly due to the noise and vibration of motor and reducer. Since the noise of drive motor is small, the noise of reducer is particularly significant which greatly affected the comfort performance of passengers. So more and more new energy vehicle plants are focusing on reducing electric vehicle reducer noise.This article is based on the promotion project of new energy vehicles reducer NVH performance, focusing on predicting the noise of reducer by using the method of radiating noise on different working conditions. Then, by optimizing the gear parameters to improve NVH performance of electric vehicles.Firstly, in order to get the natural frequencies and mode shapes of the reducer, we must build finite element model and perform modal analysis. Simulation and test results were analyzed to verify the finite element model and modal analysis results are correct. They lay the foundation for acoustic analysis.Then executing multi-body dynamics analysis of the reducer system by using LMS Virtual.Lab Motion software. We can get the varying stiffness and engaging force of the gears, then the dynamic load of the bearing and the acceleration of the housing are obtained. Based on the finite element model of the reducer housing structure, we establish its acoustic finite element model. Put the vibration data as a boundary condition of the radiation noise, conduct acoustic analysis and prediction of the gear unit. The reliability of radiation noise analysis method is verified by analyzing and comparing the simulation results with the bench test results.Finally, the method of optimizing design parameters is used for reducing radiated noise. Through increasing the total coincidence of transmission gear and modifying simulation model, the analysis and test results are compared. By comparing the noise of the reducer before and after the optimization, the validity of the optimization design method is proved.