驱动桥总成刚柔耦合建模与试验研究

Rigid-flexible Coupling Modelling and Experimental Study of Drive Axle Assembly

为准确分析驱动桥齿轮传动系统的动力学特性,指导驱动桥的减振降噪设计,进行了驱动桥总成的刚柔耦合建模和试验研究。首先,采用有限元法建立了齿轮、桥壳和主减速器壳体等结构模型;然后,结合用多体连接单元模拟的轴承、花键和传动轴中间支撑等部件,构建了完整的驱动桥刚柔耦合模型;最后,对驱动桥进行自由状态和整车安装状态下的模态试验。结果表明:驱动桥在自由状态的振型不能反映实际约束下模态振型;因此不能单独将驱动桥作为研究对象,而须进行包括与之相连接的传动轴和钢板弹簧等部件在内的整车安装状态下的模态试验;将轴承和花键等部件简化为多体连接单元,可在保证模型计算精度的前提下,显著提高计算速度;驱动桥模态仿真和试验结果误差在7%以内,说明驱动桥刚柔耦合模型是合理的,对研究驱动桥的振动噪声特性有一定的工程实际意义。

In order to more accurately analyze the dynamics characteristics of the gear transmission system of a drive axle for guiding the design of drive axle for vibration and noise reduction,the rigid-flexible coupling modelling and experimental study on drive axle assembly are conducted in this paper.Firstly,the models for the gears,axle housing and final drive housing are established by finite element method.Then,combined with the bearing,spline and the intermediate support of propeller shaft,which are simulated by multi-body connection elements,a complete rigid-flexible coupling model of drive axle is constructed.Finally,modal tests of drive axle in both free state and vehicle installation state are carried out.The results show that the vibration modes of drive axle in free state cannot reflect its actual vibration modes under constraints.Therefore,drive axle cannot be taken alone as the research object,and it is essential to perform modal test of drive axle in vehicle installation state with components such as propeller shaft and leaf springs connected.And using multi-body connection elements to simulate components like bearings and splines can significantly increase computation speed while ensuring the calculation accuracy of model with the relative error of modal simulation against modal test is less than 7%,which demonstrates the reasonableness of the rigid-flexible coupling model for drive axle,having a certain practical engineering significance for studying the vibration and noise characteristics of drive axle.