Establishment of Dynamic Model for Axle Box Bearing of High-Speed Trains Under Variable Speed Conditions

In this study, a dynamic model for the bearing rotor system of a high-speed train under variable speed conditions is established. In contrast to previous studies, the contact stress is simplified in the proposed model and the compensation balance excitation caused by the rotor mass eccentricity considered. The angle iteration method is used to overcome the challenge posed by the inability to determine the roller space position during bearing rotation. The simulation results show that the model accurately describes the dynamics of bearings under varying speed profiles that contain acceleration, deceleration, and speed oscillation stages. The order ratio spectrum of the bearing vibration signal indicates that both the single and multiple frequencies in the simulation results are consistent with the theoretical results. Experiments on bearings with outer and inner ring faults under various operating conditions are performed to verify the developed model.