Study on vibration characteristics of hub motor drive systems considering bearing stiffness effects

Hub motor drive technology, recognized for its high integration and flexible control capabilities, has emerged as a pivotal direction in the development of new energy vehicles. As a critical connecting component of the motor, the hub bearing’s stiffness characteristics directly influence the dynamic behavior of the hub motor drive system. In this study, an analytical model for the contact stiffness of the hub bearing is established, taking into account actual operating conditions. This model is then incorporated into the vibration model of the hub motor drive system. Under combined excitation from road excitation and unbalanced magnetic pull (UMP), the vibration response of the system was obtained. A systematic analysis was conducted to investigate the variation patterns of the vibration characteristics of the hub motor drive system under different operating conditions, with consideration of the bearing stiffness effect. The results indicate that the hub bearing stiffness primarily influences the dynamic tire load and wheel acceleration of the hub motor drive system. This research provides an important theoretical basis for accurately predicting the vibration behavior of hub motor drive systems and optimizing their dynamic performance.