多电机并联驱动-传动系统动力学建模及其固有振动特性分析

Dynamics Modeling and Inherent Vibration Characteristic Analysis of Multi-motor Parallel Drive-transmission System

为了解多电机并联驱动-传动系统的固有振动特性,揭示系统刚度参数对其固有频率的影响规律,考虑齿轮时变啮合刚度、啮合误差等非线性因素,采用集中质量法建立其耦合动力学模型,根据中心构件振动位移的特点,给出了3种典型的系统低阶振型,即扭转振型、横向振型和行星轮振型;研究了传动轴扭转刚度和部件支撑刚度对系统固有频率的影响。结果表明,除高阶频率外,其他频率成分对系统刚度参数的变化比较敏感,且在求解系统固有频率时应充分考虑系统的耦合效应;同时,系统刚度参数的变化会引起模态跃迁现象,即系统振动模式发生突变,增加系统动力学行为的复杂性。在动态设计过程中,应尽量避开模态跃迁点,进而避免系统产生多阶次共振现象。

In order to understand the inherent vibration characteristics of multi-motor parallel drivetransmission system,and reveal the influence of system stiffness parameters on its natural frequency,considering the nonlinear factors such as time-varying meshing stiffness and messing error,the coupling dynamics model of multi-motor parallel drive-transmission system is established by using lumped-mass method.According to the trait of the vibration displacement of center components,the three typical low-order vibration modes are given,that is,torsional vibration mode,transverse vibration model and planet vibration mode.Then,the influence of meshing stiffness and support stiffness on the natural frequencies is studied.The results show that the other frequency components are sensitive to the change of system stiffness parameters except high order frequencies,and the coupling effect of system should be taken into full account when solving the natural frequency of the system.Meanwhile,the mode jumping will occur when the system stiffness parameters change,namely,a sudden change in the vibration mode of system,and it increases the complexity of the dynamic behavior of the system.Therefore,in the process of dynamic design,the mode jumping point should be avoided as much as possible to prevent the multi-order resonance from occurring.