混合动力两级行星机构动力耦合系统动力学建模及分析

Dynamic Modeling and Analysis of Power Coupling System with Two-stage Planetary Gear Trains for Hybrid System

以基于双转子电机的混合动力传动系统的两级行星齿轮机构动力耦合系统为研究对象,考虑前后两级行星齿轮机构的齿轮副啮合刚度、中心构件的扭转支撑刚度、连接部分的扭转耦合刚度、各构件惯性等基本因素,详细推导并建立两级行星齿轮耦合系统的纯扭转动力学模型。利用两级行星齿轮机构的有关参数进行特征值问题求解,得到系统整体模型的固有特性,按照振型特点把系统的振动形式划分为三种模式:整体扭转振动模式、前排行星轮振动模式和后排行星轮振动模式。在整体模式下固有频率为单根,系统各构件均以一定幅度做扭转振动;前、后排行星轮模式下固有频率均为二重根,且除了其自身外,其他构件均无振动。归纳分析得到的各振动模式特征与前人有关结论相吻合。同时指出连接部分的耦合刚度对系统振动特性的影响,并作了初步分析。

A power coupling system with two-stage planetary gear trains is considered,which is a part of a novel hybrid power train system based on a double-rotor motor.Many fundamental factors are taken into account,such as mesh stiffness of gear pairs of the two-stage planetary gears,torsional stiffness of the central parts,torsional coupling stiffness of the connecting section,inertia of the system,etc.Purely torsional dynamic model of the coupling system is developed.The reduced-order eigenvalue problems are derived by using the related parameters of the system,and the natural characteristics of the system is shown.The vibration modes of the system are classified into three categories： overall rotational mode,front row planet mode,rear row planet mode.In overall mode,the natural frequency is a simple root and each part of the system has torsional vibration to some extent.However,the natural frequency is a double root in the other two modes and no part of system vibrates except the planet gears.It＇s found that the vibration mode characteristics agree with those of the literatures.The impact of coupling stiffness to natural characteristics of the system is point out,and preliminary analysis is proposed.