| Fast and convenient subway system has become an important symbol of urban modernization,it is not only an important basis for urban economic development,but also an important guarantee for the lives and work of the people.However,with the growth of rail transit lines and the increase in traffic,the safe operation of metro vehicles represented by metro vehicles is facing unprecedented challenges.Subway gear box as a subway vehicle traffic transmission of the key components,always affect the smooth operation of the train.Compared to other mechanical equipment,the subway vehicle gear transmission system in addition to bearing from the gear meshing caused by time-varying meshing stiffness,tooth side gap nonlinear,damping and other internal incentives and traction motor output power and torque generated by the load and other external incentives,but also suffering by the subway operating environment of the harsh,frequent and rapid start-up brake makes the transmission system at constant speed variable load conditions,as well as due to track irregularities generated by the road spectrum,such as wheel,axle transmission to the drive,so the passive wheel of the system has an impact on the gear drive system.These city rail vehicle gear drive system unique impact excitation,will directly affect the stability of the transmission system.However,the research on the dynamics of the gear system of the subway vehicle is still less and not comprehensive.Therefore,the dynamic research on the key components such as the urban rail vehicle gear transmission system is carried out,which is suitable for the safe and comfortable operation of the urban rail vehicle And promote the development of China's urban rail industry,has a positive role in promoting.The paper based on the gear parameters of the subway vehicle transmission system,the dynamic response of the three main stimuli to the gear transmission system,such as tooth surface friction,variable speed and damping,orbit irregularity,is analyzed,and the corresponding dynamic model is established.Then the numerical analysis method is used to solve the model.The dynamic response of the gear transmission system is obtained,and the influence of the excitation parameters on the gear stability is analyzed.The main work is as follows:(1)The structure and composition of urban rail transit vehicles are introduced,and the bogies of the subway gear transmission system are analyzed emphatically.The subway bogie wheel,traction drive,the central suspension,the basic brake devices and other parts are analyzed respectively.And the subway traction and braking force in the transmission between the various parts of the route was sorted out,the foundation of the analysis is established for the dynamic analysis of the subway gear transmission.(2)In the study of the influence of tooth surface friction on the dynamic influence of gear transmission system,a two-degree-of-freedom dynamic coupling model was established.The influence of tooth surface friction excitation on the dynamic response of gear system was analyzed.The time-varying meshing stiffness of the straight teeth is fitted by the energy method,and the internal and external excitation of the tooth side clearance,damping and load are also considered.Through the qualitative analysis of the model,the variation of the friction coefficient of the gear system with the tooth surface shows the period of the periodicity,quasiperiodic,bifurcation and chaos,and the experiment is carried out based on the subway gear box vibration test bed.Model and analysis of the correctness of the conclusions.(3)The dynamic model of the grating-torsion-shaft of the metro helical gear is established.The model considers the time-varying meshing stiffness generated during the gear meshing process,the meshing error caused by the installation machining error and the non-linearity of the gear itself Parameters,as well as subway operating conditions under the external parameters.The Runge-Kutta numerical integration method is used to solve the differential equation of the differential equation of the gear transmission system,and the system response state diagram is obtained.The periodic motion,quasi-periodic motion,bifurcation and chaotic motion of the system under the excitation frequency and meshing damping ratio are analyzed by means of the system state judgment standard such as vibration time-domain waveform,phase diagram,Poincare graph and bifurcation diagram.(4)A dynamic model of metro helical gear considering the road spectrum excitation is established for the special operation condition of the subway running on the rail and excited by the track unreasonable road.Similarly,based on the full consideration of internal and external excitation,the model focuses on the impact response of the gear system due to orbital irregularity.Through the analysis and analysis of the model,the dynamic stability and dynamic transmission error of the gear system with or without road spectrum excitation are qualitatively analyzed.The results show that the one-cycle motion of the gear system affects the quasi-periodic motion and affects the dynamic transmission error parameters of the gear.Finally,based on the ADAMS dynamic simulation software,the three-dimensional modeling and simulation of the gear transmission system with orbital irregularity excitation is carried out to further verify the correctness of the model. |
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