基于集中-分布参数模型的车辆机电传动系统动力学响应及影响规律

Electromechanical transmission systems are widely used in new energy vehicles, high-speed trains and other fields. With the development of electromechanical transmission system in high speed, heavy load and light weight, its dynamics characteristics become more and more complex. The dynamics response and influence factors of a fixed shaft gear transmission system driven by a motor under both the action of bending-torsion-pendulum coupling excitation and nonlinear meshing excitation of involute spur gears are analyzed based on lumped-distributed parameter model.A concentration-distributed parameter dynamics model is established by combining the finite element method and the lumped parameter method. The generalized -a numerical method is used to solve the dynamics responses of the system, and the influences of the vibration of shaft and the eccentricity of gear on the dynamics responses of the system are analyzed in detail. It is found that the large von Mises alternating stresses at two points of both the gear installation position on the shaft and the connection position between shaft and bearing are predicted by using the lumped-distributed parameter model. In addition, it is found that the deformation of shaft can induce the new frequencies, such as the bending vibration frequency along Y and Z directions of shaft and the combined frequency of both the mesh frequency and the bending vibration frequency. The simulated results show that the bending vibration frequencies along Y and Z directions of shaft are 1 125 Hz and 874 Hz, respectively, and the magnitude and amplitude of the two frequencies are only determined by the natural characteristics of shaft. The influence laws of gear eccentricity on the system are as follows: with the increase in gear eccentricity, the time-varying dynamic mesh force, backlash, von Mises alternating stress and gear center vortex trajectory increase significantly, the maximum dynamic mesh force increases linearly with the gear eccentricity, and the increment ratio is 1.77×10⁹.