Mechanical-thermal coupling model and fatigue life analysis of axle-box bearings of high-speed train

The axle box bearings of high-speed trains often operate in extremely harsh environments, bearing loads from different directions. Long-term operation and frequent changes in working conditions can easily lead to axle box bearing failures. Therefore, it is extremely important to study the mechanism of axle box bearings. Firstly, the medium of thermal deformation establishes a coupling relationship between the system dynamics model and the thermal grid model, and then obtains the thermal force coupling model of the high-speed train axle box bearing. The coupling model is validated from the perspectives of system dynamics response and temperature response, proving its effectiveness in system dynamics response and temperature characteristic response. Comparing the coupling model with the dynamics model, it is found that thermal deformation complicates the dynamic response. Finally, using the Lundberg-Palmgren (L-P) bearing fatigue calculation method and damage accumulation theory, the bearing fatigue life is calculated, and it is found that thermal deformation deteriorates the bearing operating environment, reducing the bearing fatigue life. Finally, by comparing the bearing fatigue life under different working conditions, it is concluded that the faster the vehicle speed, the greater the load, and the smaller the initial radial clearance of the bearing, the fatigue life of the bearing is reduced. The shorter the lifespan.