点接触弹流润滑条件下的深沟球轴承表面局部缺陷动力学建模

Dynamics modeling on local defect of deep groove ball bearing under point contact elasto-hydrodynamic lubrication condition

传统轴承动力学模型多为无润滑干接触状态下建立的接触力学模型,没有考虑润滑对轴承振动的影响。由于球轴承内部钢球与滚道之间润滑油膜的存在,油膜影响轴承的接触刚度。基于非线性赫兹接触变形和弹性流体润滑,提出了一种深沟球轴承局部缺陷的两自由度动力学模型。首先将接触变形、径向间隙和缺陷的连续性变化关系对轴承的局部缺陷影响提出了模拟的方法,然后加入了弹流润滑对轴承接触刚度的影响这一因素,并建立深沟球轴承的两自由度动力学模型,能更加准确的模拟轴承实际运转时的真实状态。最后通过振动响应的仿真信号与轴承故障实验台的数据进行对比,验证这种模型的准确性,为轴承故障诊断提供了理论依据。

The traditional bearing dynamics models are mostly based on dry contact mechanics,in which the effect of lubrication on bearing vibration has not been taken into account. The contact stiffness of the bearing will be affected due to the existence of lubricating oil film between the raceway and ball with local defect. Taking into account the relationship among the contact deformation,radial clearance and the defects,a simulation method for local defects was presented.Then,a two degrees of freedom dynamic model of the deep groove ball bearing was constituted with consideration of the nonlinear Hertzian contact deformation and the influence of elasto-hydrodynamic lubrication on the bearing contact stiffness. The model can simulate the actual condition of bearing operation more accurately. Comparing the signals of vibration responses in the simulation with the experiment data of actual fault bearings,the correctness of the model was verified. It could provide a theoretical foundation for fault diagnosis of bearing.