Characteristics analysis on bearing rotor system of high-speed train with track irregularity

Dynamic modeling method is an important means to study the motion state of high-speed train bearings. However, most models ignore the influence of temperature, lubrication, TI (Track Irregularity) or others, and the analysis results are not close to reality. To address these problems, this paper proposes a mechanical thermal coupling model of bearing rotor system in high-speed trains with considering the influence of TI. The force and temperature are unified through the change of grease temperature and equivalent contact stiffness caused by grease. The differences of vibration response and transient temperature field distribution of the system are compared and studied under the conditions of considering TI and not considering. The results show that the TI has a profound impact on the characteristics of vibration and temperature, and based on this, a path of bearing failure mechanism is illustrated. The effectiveness of the model is verified respectively by using the comprehensive bearing test rig and the actual line data in terms of vibration and temperature. The results show that the spectrum analysis results of the outer ring vibration acceleration of the model have little error with the experiment. The change of system node temperature is also in good agreement with the actual line data. The influence of TI on system stability under the conditions of different speed, temperature and bearing faults is deeply studied by using two-dimensional moment invariant. The results show that it plays a side effect. Generally speaking, the model can better reflect the motion behavior of the real bearing and predict the change of node temperature. The simulation results and corresponding analysis results have certain engineering application value. [Display omitted] •A mechanical thermal coupled model for the wheelset system was established.•The coupling model was validated by utilizing test bench and actual line data.•The evolutionary mechanism of faults on axle box bearing was revealed.•The system motion stability affected by track irregularity was evaluated.