Research On Vibration Characteristics Of High-Speed Train Gear Transmission System Under Wheel-Rail Excitation

As an important part of the power transmission of high-speed trains,the gear transmission system is responsible for transmitting the power output of the traction motor to the wheelset,which plays an important role in ensuring the operation of high-speed trains.With the continuous deterioration of the train running environment,the wear and contact fatigue between wheel and rail are becoming more and more serious,resulting in wheel wear and track irregularity.Due to the influence of wheel non-circularization and track irregularity,the vibration of vehicle parts is aggravated.Therefore,this paper considers the wheel-rail excitation under the train operation environment,mainly including rail corrugation,wheel polygon and Wuguang spectrum excitation,and analyzes its influence on the vibration characteristics of the high-speed train gear transmission system.The main research contents are as follows:Firstly,based on multi-body system dynamics,the vehicle-track rigid-flexible coupling dynamic model was established,the rail and wheelset were considered as flexible bodies,and the rail corrugation and wheel polygon excitation were represented by harmonic functions.Considering the meshing characteristics of helical gears in high-speed trains,the gear meshing model was established by using force element 225 in dynamics software.The correctness of the model was verified by nonlinear critical speed verification and running stability evaluation,and compared with the existing experimental data such as vehicle vibration acceleration and frequency.Secondly,the research scope of excitation parameters was determined by analyzing the research status of wheel-rail excitation.The rail corrugation wavelength was 100-150 mm,the wave depth was 0.01-0.05 mm,the wheel polygon order was 20-25,and the amplitude was0.01-0.05 mm.At the same time,the speed was set to 250,300,350 km/h.The dynamic simulation analysis of vehicle vibration under different working conditions was carried out,and the dynamic response characteristics and vehicle dynamics indexes of high-speed train gear transmission system were obtained.The working conditions affecting the stability and safety of vehicle operation were summarized.Finally,the influence of flexible wheel-rail and rigid wheel-rail on gear vibration characteristics was compared and analyzed in time domain and frequency domain.The vibration signal processing method was used to analyze the influence of various working condition parameters on the vibration characteristics of gear transmission system,and the influence law of different working condition parameters on the vibration of gear system was explored.The frequency spectrum components in the gear meshing process were obtained by frequency domain analysis.The causes of abnormal vibration of the gear system under some specific working conditions were analyzed,and the main working condition parameters affecting the vibration of the gear system were summarized.When the vehicle speed was 300km/h,the vibration acceleration of the gear system was larger under the action of 0.03 mm rail corrugation wave depth,140 mm wavelength and 0.05 mm wave depth,120 mm wavelength,when the vehicle speed was 300 km/h,the wheel polygon order was 20,the amplitude was 0.03-0.05 mm,and the vehicle speed was 350 km/h,the order was 21-22,and the amplitude was 0.01-0.03 mm,the vibration response of the gear system was more intense.The research results can provide a basis for the later development of planned rail grinding and wheel repair.