一种考虑轴承缺陷影响的机构动力学分析方法

为有效地揭示轴承滚道缺陷特征对高速机构动态响应特性的影响规律，在多体动力学理论框架下提出一种考虑轴承缺陷影响的机构动力学分析方法。该理论采用力约束方法构建机构中滚动轴承转动副模型，通过分析轴承中各滚动体与滚道缺陷几何特征之间的接触关系，计算滚动体接触载荷并获取轴承转动副等效约束反力，探讨轴承缺陷激励对高速机构动态性能的影响规律。在此基础上，以含深沟球轴承的曲柄滑块机构为例，分析轴承滚道表面局部式缺陷和分布式波纹度缺陷对机构动力学特性的影响。研究表明，轴承滚道缺陷将引发轴承各滚动体接触动载荷突变。这种突变载荷经传播后，直接影响着机构中各构件的运动状态，对高速机构运动平稳性将产生严重影响。此外，该理论方法具有一般性，具有不同滚道几何缺陷特征的滚动轴承均可嵌入到本方法中，分析轴承转动副缺陷对各类机构动力学特性的影响。

General Method for Dynamic Analysis of Mechanisms Considering the Effect of Bearing Defects

In order to effectively reveal the influence of bearing defects on dynamic response of high-speed mechanisms, a general method for dynamic analysis of mechanisms considering the effect of bearing defects is proposed in the framework of multi-body dynamics theory. In this method, the rolling element bearing joint in mechanism is constructed by using the force constraint. By analyzing the geometric contact relationship between rolling elements and defects on raceway surfaces, the contact load on each rolling element and the equivalent bearing constraint reaction force can be obtained. The influence of the bearing defect excitation on the performance of high-speed mechanism is explored. On this basis, a slider-crank mechanism containing a rolling element bearing with localized defects and distributed waviness defects on raceway surfaces is chosen as an example to demonstrate application of the methodologies. The results indicate that the defects can stimulate the sudden change of the dynamic load on each rolling element. After transmission, the vibration of the bearing load directly affects the state of motion of each component in mechanism and has a strong impact on motion stability of the high-speed mechanical systems. Furthermore, the theoretical method presented is general. Different bearing models with different geometrical defects can be embedded within this approach.