Multi-Physical Coupling NVH Analysis and Optimization of 3-in-1 Electric drive Assembly

Due to the competition in the new energy vehicle market and the increase in consumer demand, the NVH (noise, vibration and harshness) performance of electric vehicles has become an important research work. Firstly, aiming at the NVH problem of a new pure electric vehicle three-in-one electric drive assembly, the main excitation source and main transmission path of vibration and noise of electric drive assembly are analyzed. Then, a multi-physics coupling method is established to predict and optimize its NVH performance. It includes stator structure optimization; Dynamic stiffness characteristics and material optimization of rotary and electronic control plates and design optimization of damping. Finally, experiments are carried out to verify the optimization effect of this method on the noise of electric drive assembly. Through the comparison of the order slices of typical order noise, it is observed that the 22th order of the first gear of the reducer, the 5.94th order of the second gear and the 8th order, 24th order and 48th order of the motor vibration noise are significantly reduced under the WOT working condition, and the NVH performance of the vehicle is significantly improved. This method has certain reference value for improving NVH performance.