Analysis Of Whine Noise In Miniature Electric Vehicle Differential And Optimization Of Gear Tooth Modification

The rear differential of miniature electric vehicles can ensure smooth directional driving on the road by allowing the left and right wheels on the same car axle to rotate at different speeds and distribute appropriate torque due to its structural characteristics.However,due to errors in design,manufacturing,and installation,the gear pair in the differential tends to produce certain levels of vibration,noise,and uneven load distribution during meshing and transmission,seriously affecting the overall acoustic quality of the vehicle.This paper uses experimental analysis,gear shape optimization design,and finite element simulation analysis to reduce the differential whine noise of a micro-electric vehicle rear differential with vibration noise problems and improve the acoustic quality of the whole vehicle.The main research contents are as follows:First,a test bench for the rear differential of miniature electric vehicle was built using the DH5902 data acquisition and analysis system,sound pressure sensor,unidirectional vibration acceleration sensor,and speed sensor to collect and measure the speed signal,far-field noise,and vibration signal of the rear differential of the miniature electric vehicle.The collected noise and vibration signals were processed using spectral analysis methods to determine that the cause of gear whine is the meshing transmission of the differential gear pair.Next,based on the meshing relationship and spatial position information of the differential gear pairs,a transmission system model of the differential gears was established in KISSsoft software to analyze the impact of each profile parameter on the gear transmission performance index.The results show that the tooth profile modification has the maximum impact on transmission error,while tooth direction modification has a greater impact on the maximum contact stress of the tooth surface and the maximum bending stress of the tooth root.Then,multi-objective optimization of the differential gear profile was carried out using KISSsoft’s own optimization function,response surface method,and genetic algorithm.The comparison shows that the gear shape solution obtained from the response surface optimization design and genetic algorithm achieve better tooth meshing performance.Finally,transient dynamic analysis of the meshing process of the differential gear pair with different shape modification parameters was performed using finite element software to verify the correctness and effectiveness of the optimized scheme by comparing the changes in normal stress and vibration acceleration of the gear contact surface under high and low gear ratios,thus reducing gear whine noise and improving the acoustic quality of the rear differential of electric vehicles.