Dynamics modelling and vibration characteristics of urban rail vehicle axle-box bearings with the cage crack

The cage crack changes the structural stiffness on different components, and therefore affects its relative contact forces. Furthermore, the crack may cause the fault characteristics on the urban rail vehicle axle-box bearing. Despite all this, there is still a lack of discussion and summary on the dynamics modelling and vibration characteristics analysis of axle-box bearings with the cage crack. For filling this gap, two cage crack models are proposed, which are respectively constructed when the crack generates in the cage bridge or arm. Then, these models are coupled to the axle-box bearing model in a vehicle-track coupling model. Thereinto, the friction force and the motion of rollers are considered, and the cage is decentralized into several segments for facilitating the study of the force between adjacent cage segments. At last, the dynamic characteristics of axle-box bearings with the cage crack are investigated, and the changes in contact forces due to the cage crack are also analyzed. This study can provide valuable information for axle-box bearing condition tracking and monitoring.