Vibration Analysis of Axle Box Bearing Considering the Coupling Effects of Local Defects and Track Irregularities.

Purpose: Axle box bearings are the crucial components of high-speed trains (HSTs). Based on Gupta's model, a dynamic model of cylindrical roller bearing is presented to describe the dynamic behaviour of the axle box bearing more realistically, with the coupling effects of local defects and wheel-rail disturbances considered. Methods: The Hertzian contact force and lubrication traction between the raceway and the roller are taken into account, as well as the gravity of the car body and the wheel-rail contact force. The local defects are described as the time-varying deflection excitations applied to the outer raceway, inner raceway and rollers respectively. By transforming the power spectrum of track irregularity into time-domain, the random excitation is input as external excitation. The fourth-order Runge-Kutta method is used to solve the equations of motion. Results: The dynamical behaviors of the bearing with different defects are analyzed. Besides, the effects of vehicle speed on bearing acceleration are studied. Conclusion: The outer raceway and inner raceway failure are coupled strongly with the track irregularity, whereas such coupling effect for roller failure is relatively small. [ABSTRACT FROM AUTHOR]