Dynamic Modelling and Vibration Analysis of Axlebox Bearings Excited by Internal Clearance and External Random Excitations

Axlebox bearings are vital components of high-speed train transmission systems. The vibration characteristics of these bearings are influenced by both external wheel-rail contact and internal clearance. However, this coupling effect has not been thoroughly explored. This paper introduces a dynamic model for axlebox bearings, incorporating internal clearance, track irregularities, and car body. The dynamic response of the axle box bearing is studied using low-frequency spectrum analysis and high-frequency envelope demodulation technology which are two common approaches used for bearing condition monitoring. External random excitation and internal clearance effects on vibration characteristics are analysed. Additionally, the distribution of contact forces under various track irregularities and internal clearance conditions are studied. The results show that the track irregularities have a greater influence on the vibration characteristics of the axle box bearing than the internal clearance. This study offers some theoretical insights into the condition monitoring of axlebox bearings.