Analysis and optimization of tip-out transient dynamic characteristics of electric vehicle reducer under multi-bearing collaborative preloading

In this study, the transient dynamic response of an electric vehicle secondary reducer with a multi-bearing cooperative preload was studied. The time-varying mesh stiffness, mesh damping, backlash, axial dynamic stiffness, and axial preload of the system are considered. A novel transient dynamics model was established for the multi-bearing cooperative preloading of the electric vehicle secondary reducer suitable for transient conditions. The accuracy of the built model is verified using a bench test. Subsequently, the transient dynamic response of the reducer system under tip-out working conditions was determined. The optimal preload combination of the bearing was determined using an optimization algorithm. The simulation results show that, under the tip out working condition, increasing the bearing preload can effectively restrain the transient impact of the reducer system, and the optimal bearing preload combination obtained by multi-objective optimization using an optimization algorithm can significantly reduce the transient shock problem of the electric vehicle drivetrain. This study provides theoretical support for suppressing transient shocks in electric vehicle reducer.