The Dynamics Analysis Of CRH2 Multiple Units Gear System

The gear transmission system that is an important part of the high speed train drive system in china has a wide range of applications in mechanical transmission. With the improvement of the high-speed train operating speed, the gear performance requirements what requires a gear to meet the high speed, high power, light weight and small size also will be improved. Gear in satisfying these requirements must also pay attention to the safety performance, therefore, it’s important to study the gear system dynamics and analyze the gear system dynamic characteristics of the high-speed trains, which has an important role in gear system reliability design.In this paper, the gear transmission system of CRH2 EMU drive system was studied with gear system dynamics theory as the foundation, and established a more realistic gear dynamics model by use of lumped parameter method, the helical gear bending-torsion-axis-pendulum coupled vibration analysis model was established in full consideration of the nonlinear factors such as time-varying mesh stiffness, error excitation and backlash, and the dynamics differential equations was based on the model. The calculation of time-varying mesh stiffness that is one of the important parameters of internal motivation in gear system will be discussed and computing.The gear transmission system model of the high-speed train was established by using the three-dimensional modeling software Pro/e, and was imported to the multi-body dynamics simulation software ADAMS in its simulation analysis. The speed of the gear and the load torque acting on the wheel when the train moved in different speed of 120km/h, 140km/h,160km/h,180km/h,190km/h,200km/h was gotten according to the traction motor performance curves, and was imported to simulation in ADAMS. From the simulation results can be learned:in the gear meshing process, the meshing force between gear teeth was fluctuated within a certain range and changed in periodicity because of the gear teeth contact stiffness factor, and it contained dynamic load components in gear engagement force; the dynamic load components was not only associated with the teeth mesh stiffness, but also has some links with external excitation of the gear system. When the input torque of motor keep same, the dynamic meshing force of gear system basically unchanged with the increase of tooth surface friction coefficientCo-simulation using ANSYS and ADAMS, established the rigid coupling model of high-speed train gear transmission and got the gear inherent characteristics by modal analysis of the gear in ADAMS:natural frequencies and mode shapes, that’s provided theoretical data for the parameters of drive system selected.