球轴承点接触区油膜阻尼系数的计算与理论分析

Theoretical Analysis and Calculation of Ball Bearing Oil Film Damping

基于弹性流体动力润滑方程,重新推导球轴承点接触区油膜阻尼系数的计算模型。对比分析该模型方程与纯挤压情况下的拟稳态点接触弹流动力润滑方程,并依据模型方程解与考虑振动的弹流动力润滑方程解之间的关系,提出新的求解方法及过程,给出考虑热效应和球轴承点接触特点的修正计算模型,确定迭代边界条件并进行求解。结果表明,模型解与理论预测结果相符,证明该模型计算结果具有可信性。分析各因素对油膜阻尼黏度系数的影响,表明油膜黏度阻尼系数随接触面间润滑油卷吸速度、润滑油初始黏度的增大而减小,随接触区法向载荷的增大而增大。

Based on point contact elastohydrodynamic lubrication （EHL）equation, the calculation model of oil-film damping on point contact area of ball bearing was re-deduced, and the model equation was compared with the point contact pure squeeze EHL equation. According to the relationship between this calculation model solution and EHL equation solution, a new method for solving this model was proposed. A revise equation was deduced considering ball bearing contact characteristic and thermal effect, and the boundary conditions were given for calculation. The solutions of the damping calculation model correspond to the theoretical predict results,which shows the dependability of this model. The effects of lubricant entrainment velocity and initial viscosity, and the contact load on oil-film damping were analyzed. The results show that the oil-film damping is decreased with the increase of lubricant entrainment velocity or lubricant initial viscosity, and increased with the increase of contact load.