Analysis And Optimization Of Vibration And Noise Characteristics Of Hybrid Transmission

As one of the most important components in a hybrid electric vehicle,the gearbox is internally integrated with a permanent magnet synchronous motor and a gear transmission system.When the vehicle is running,the gearbox is subjected to the combined action of the radial electromagnetic force generated by the internal motor and the dynamic excitation generated when the gear transmission system is engaged,thus generating large vibration and noise,which affects the comfort of the vehicle occupants to a certain extent.Therefore,it is of great significance to analyze and improve the vibration and noise characteristics of the hybrid gearbox.Aiming at the radial electromagnetic force generated by the permanent magnet synchronous drive motor and generator in the hybrid gearbox,the two-dimensional electromagnetic analysis model of the drive motor and generator is established in Maxwell electromagnetic analysis software,and the time domain and frequency domain characteristics of the radial electromagnetic force generated by the motor are analyzed,in which the simulation analysis is consistent with the theoretical analysis results.The obtained radial electromagnetic force is used as the electromagnetic excitation for vibration and noise analysis of gearbox.Aiming at the dynamic excitation generated by the gear transmission system in the hybrid gearbox,a multi-body dynamic model of the gear transmission system in the gearbox is established in ADAMS,and the rotating speed of each gear shaft and the dynamic excitation generated at the bearing seat of the gearbox are analyzed,and the dynamic excitation generated by the gear transmission system at the bearing seat of the gearbox is extracted,and the obtained dynamic excitation is taken as the mechanical excitation for the vibration and noise analysis of the gearbox.Using the obtained electromagnetic excitation and mechanical excitation,the vibration response of the finite element model of the gearbox is analyzed by modal superposition method in LMS virtual lab software,and the vibration characteristics of the gearbox during operation are studied,and the vibration response test of the gearbox sample is carried out at the same time.In the acoustic analysis module,the radiated noise of the gearbox is analyzed with the vibration response result as the boundary condition,and the noise frequency domain curve of the gearbox is obtained.The analysis of the sound pressure frequency domain curve provides reference for the noise reduction optimization of the gearbox.Based on the analysis results of radiated noise of gearbox,from the point of view of noise excitation source,by comparing the radial electromagnetic excitation generated by driving motor under different structural parameters,the reasonable structural optimization parameters are determined to reduce the electromagnetic excitation generated by driving motor,and the gear tooth modification design of output shaft gear pair is carried out to reduce its dynamic mechanical excitation.The optimized electromagnetic excitation and mechanical excitation are used to analyze the radiated noise of the gearbox,and the results of the radiated noise of the gearbox before and after optimization are compared.The results show that the noise amplitude of the gearbox after optimization is reduced.In this paper,the vibration and noise characteristics of hybrid gearbox are analyzed by considering multiple excitation sources,and the noise reduction optimization design is carried out for the excitation sources of noise,which provides a reference for the analysis and improvement of NVH performance of this kind of hybrid gearbox in the design stage.