基于 EHL 理论的脂润滑轴承沟道表面缺陷研究

摘要

根据脂润滑轴承失效表现形式，分析了滚动轴承沟道表面缺陷产生的原因，建立了球－沟道表面缺陷条件下的脂润滑弹流数学模型和油膜厚度方程，采用数值计算方法分析了不同尺寸的表面缺陷及表面光滑条件下的脂润滑弹流润滑油膜压力和油膜厚度分布规律。结果表明：轴承工作过程中，球－沟道表面会形成位置、尺寸和形状随机分布的凸起和凹坑；相比于光滑表面，缺陷表面会引起油膜压力和油膜厚度显著变化，且对于同类型表面缺陷，随着缺陷尺寸的增大，引起油膜压力和油膜厚度分布变化的规律大致相同但效果增强；表面缺陷均会对轴承润滑脂的润滑效果造成不良影响。%According to failure form of grease lubricated bearings,the reasons are analyzed for raceway surface defects of rolling bearings.The mathematical model of elastohydrodynamic lubrication (EHL)and film thickness equation are established for grease -lubricated ball bearings having balls and raceway surface with defects,the distribution rules of film pressure and thickness for surface with defects of different size and smooth surface are analyzed by numerical calcu-lation methods.The results show that random surface pits and protuberances with different location,size and shape are generated on balls and raceway surface during bearing operation.Compared with smooth surface,a noticeable change for film pressure and thickness is caused by defective surface.For same type of surface defect,the varying pattern for distribution of film pressure and thickness are similar,but the effect is improved with the increase of defect size.The surface defect has harmful effects on lubricating performance of grease for bearings.