| High-speed trains,as an important infrastructure of public transportation and nationals,have developed rapidly under the background of national transportation policy support.At present,China’s high-speed train technology has ranked among the top in the world,and has gradually become one of the country’s scientific and technological brands.The development of social economy is also inextricably linked with it.In order to meet the increasing travel demand of people,the continuous construction of high-speed railway,the continuous innovation of highspeed train technology,and the train’s running speed is also a new high,so the high-speed running has higher requirements for the power transmission system of the train bogie,in which the gear transmission system plays a very important role in the process of power transmission.Because the gear transmission system is inevitably affected by the internal and external excitation,the dynamic contact of the gear pair shows more complex time-varying characteristics in the process of power transmission,which seriously affects the ride stability,safety and comfort of the train.This paper is based on the Jiangxi Provincial Natural Science Foundation’s key project "Research on the Contact Fatigue Failure Mechanism of High-speed Train Transmission Gears under Spatial Coupling Vibration Load of Wheel-rail System"(Acceptance Number: S2018ZRZDB0191),focusing on the gear pair dynamics under the influence of internal and external excitation of high-speed train gear transmission systems The analysis of contact characteristics starts the following work.The analysis of the dynamic contact characteristics of the gear pair under the influence of the internal excitation of the high-speed train gear transmission system is mainly aimed at the displacement excitation caused by the assembly gear transmission error on the bogie,the tooth surface friction and wear,and the parameter excitation caused by the tooth surface contact stiffness.Including the change of the gap between the tooth side and the center distance of the gear pair caused by gear installation or long-term work,and the parameter excitation mainly includes the friction coefficient of the tooth surface and the contact stiffness of the gear after long-term work.In the analysis of the dynamic contact characteristics of the gear pair under the influence of displacement excitation,the finite element analysis method is mainly used.The optimization module of the finite element software ANSYS is used to parameterize the gear center distance and the side clearance,which are within the scope of industry standards.Five groups of parameters were selected,and the contact force,average stress,and average strain of the gear pair were solved,and then the results were quantitatively analyzed.In the dynamic contact analysis of gear pair under the influence of parameter excitation alone,the contact stiffness factor is used to represent the contact stiffness,and then the friction coefficient and contact stiffness factor of gear face are parameterized by the optimization module of ANSYS.Five groups of parameters are selected within the industry standard range to solve the contact force,average stress and flatness of gear pair respectively Uniform strain,quantitative analysis of the results,and finally analysis of the dynamic contact characteristics of the gear pair under the influence of internal excitation of high-speed train.The dynamic analysis of gear pair contact under the influence of external excitation on the gear transmission system of high-speed train is mainly aimed at the excitation caused by the load end and drive end of the gear transmission system in the power transmission route.Among them,the excitation source at the load end mainly comes from the complex wheel rail relationship,including whether there is vehicle body vibration,whether there is force excitation caused by track irregularity,and whether there is parameter excitation caused by the change of wheel polygon order.In the analysis of the dynamic contact characteristics of the gear pair under the influence of the driving end excitation,based on the electromechanical joint simulation control model built by the dynamics software SIMPACK and the simulation software SIMULINK,the fluctuation speed and torque and vibration acceleration of the gear meshing transmission are obtained and converted.The high-frequency vibration excitation is applied to the finite element model,and then the changing rules of the dynamic contact characteristics of the gear pair under the influence of constant speed and constant torque and variable uniform speed harmonic torque are compared and analyzed.When analyzing the dynamic contact characteristics of the gear pair under the influence of the load end excitation,the dynamic software SIMPACK is mainly used to simulate whether there is track irregularity or not,and whether the order of the wheel polygon changes.The fluctuating speed and vibration acceleration of the gear meshing transmission are obtained,which are converted into highfrequency vibration excitation and applied to the finite element model for solution Then the dynamic contact characteristics of the gear pair are analyzed. |
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