Research On Reliability Test System For Gearbox Of High-speed Train Based On Vibration Excitation

Gearbox is the core part of high-speed train transmission system,and its safe and reliable performance is directly related to the normal operation of the entire train.With the rapid development of high speed rail industry,the pace of localization of gear boxes is accelerating,and the research of gearbox performance has attracted more and more attention.The circuit test has the disadvantages of long cycle,high cost,low safety and feasibility,and the simulation analysis can not reflect the true performance of the gear box,while indoor bench test can simulate the actual service condition of gearbox,detect its performance more quickly and accurately,and get the data base with research value.When the train runs,the gear box not only works at high speed and heavy load,but also bears the vibration excitation caused by the change of the wheel-rail relationship,and the vibration is the key factor that causes the failure of the gear box.At present,there are few researches on the performance test equipment for gearbox of high speed train under the vibration excitation environment at home and abroad.Based on this,this paper aims to develop an original set of experimental system which can simultaneously carry on vibration excitation loading and load simulation,to explore the reliability of the gearbox under the vibration environment.Analyzed the main vibration form of the gearbox.Established a multi-body dynamic analysis model including gear box and motor to simulate the vibration response of the gearbox under random excitations,and obtained the variation law of vibration acceleration with the speed of vehicle.According to the test items and technical requirements,designed five kinds of test system structure schemes satisfying functional requirements,and expounded the structure and working principle of each scheme.After comprehensive evaluation and analysis,the scheme of gear box test bed with electro-dynamic power closed-loop and electromagnetic excitation has been chosen as an ideal scheme.Designed and analyzed composition systems of the test bench,including the selection arrangement and structure check of vibration excitation device,the design of flexible support and guidance system and the introduce of the vibration control principle.Combining with finite element dynamic analysis and system identification method,studied the vibration transfer characteristics of the test bed structure.Analyzed respectively the steady state and transient dynamics of the mechanical structure of vibration system,sampled the vibration signal of the test gear box,identified structural system parameters by using frequency identification and time domain identification,and obtained the vibration transfer function whose identification reliability has been verified.