考虑弹流润滑及滑动作用下滚动轴承系统局部缺陷位移激励动力学建模

Dynamic modeling for local defect displacement excitation in rolling bearing systems under elasto-hydrodynamic lubrication and slip

滚动轴承动力学模型可深入的分析轴承局缺陷动态响应特性。针对滚动轴承局部缺陷动力学建模在弹流润滑、滑动和轴承座等方面考虑因素不全的问题,建立弹流润滑及滑动作用下滚动轴承系统局部缺陷位移激励的二自由度动力学模型。首先对滚动体与滚道间的接触刚度、润滑油膜刚度和阻尼、轴承座刚度和阻尼计算并求得总的接触刚度和阻尼,然后再加入滑动更能真实的模拟轴承实际的运转情况;根据牛顿第二定律建立了局部缺陷轴承动力学方程,利用四阶龙格库塔方法求解,得到轴承局部缺陷的动态响应。通过对比故障滚动轴承试验与模型模拟的结果,验证了所建模型的正确性。

The dynamic model of a rolling bearing can be used to analyze dynamic response characteristics of its local defect.During dynamic modeling of local defects in rolling bearing systems,bearing sliding,bearing elasto-hydrodynamic lubrication and bearing pedestal may not be considered.Here,a2-DOF dynamic model for local defect displacement excitation in a rolling element bearing system was established under elasto-hydrodynamic lubrication and slip.Firstly,contact stiffness between rolling elements and bearing races,lubricating oil film stiffness and damping,bearing pedestal stiffness and damping were calculated to obtain the total contact stiffness and damping.Then the actual running state of a rolling bearing was simulated considering rolling element slipping.According to Newton motion laws,dynamic equations of a bearing with local defect were built.The fourth-order Runge-Kutta method was used to solve these equations,dynamic responses of the bearing’s local defect were obtained.Comparing test results of a faulty bearing with the above simulated ones,the correctness of the established model was verified.