Dynamic Responses of Gear Transmission System of High-Speed Train Due to Wheel Polygonal Wear

As a key component of high-speed train, service conditions of gear transmission system become worse caused by the intended wheel-rail interaction due to the higher speed and wheel failures. To investigate the dynamic responses of gear transmission system, a novel vehicle dynamics model is established based on vehicle and gear dynamic theory. This comprehensive model enables detailed investigation on the system dynamic responses in the vehicle vibration environment induced by track irregularity, wheel polygonal wear and the internal mesh process of gear pair (time-varying mesh stiffness, gear errors, et al.). Moreover, the flexible deformation of gearbox housing is considered using modal superposition methods. The proposed model is validated by comparing the results obtained by simulation and field tests. Besides, the realistic wheel polygonal wear obtained via long term field tests is adopted in the dynamics model. And then, the gear transmission system responses are investigated and assessed in terms of dynamic transmission errors, meshing force and gear pair contact stress under the excitations: track irregularities, wheel polygonal wear. Furthermore, the proposed methods can be used for failure assessment of gear transmission system for any rail vehicle, which is useful to condition monitoring and maintenance.