考虑滚道表面油层分布的滚动轴承润滑分析

Lubrication Analysis for Rolling Bearing Considering Lubricant Layers Distribution on Raceway Surface

研究表明供油量对弹流润滑性能产生显著影响.滚动轴承中由于离心力和滚动体的反复滚压,滚道表面上的润滑剂呈现出非均匀分布的特点.大多数润滑剂被推挤到滚道的两侧,致使接触区的入口间隙不能被完全充满,导致乏油润滑,滚动体与滚道间接触压力接近于赫兹压力分布,膜厚较全膜润滑有明显的减小.本文基于润滑剂的流量连续建立滚道表面油层厚度分布模型,考虑润滑接触压力的影响,计算滚道上的侧流量以预测轴承滚道上补给油层厚度及形状随时间的变化规律;进而以此作为滚动体和滚道接触区的入口油层厚度,采用统一Reynolds方程法数值模拟计算每个时刻轴承滚道与滚动体之间的润滑油膜厚度,压力分布等参数,分析轴承在点接触乏油条件下运行的润滑性能.

The inlet supply layer thickness has a great effect on elastohydrodynamic lubrication performance. The lubricant on raceway surface is distributed unevenly due to the effects of centrifugal force and continuously rolling by roiling elements. The contact inlet cannot be completely filled as most of lubricant is extruded to the sides of raceway, which leads to the starved lubrication. In that case, the contact pressure between the raceway and rolling elements is very close to the Hertzian distribution, and the film thickness is significantly thinner than the fully flooded lubrication. Based on the flow continuity of the lubricant, the layer thickness distribution model on raceway surface was proposed. With considering the side flow due to the hydrodynamic pressure and over rolling of roiling elements, the variations of the supply layer shape and thickness on the raceway were predicted. It is used as the inlet oil supply condition between rolling elements and raceway to numerically predict the lubrication parameters, e. g. the film thickness and pressure distribution based on the unified Reynolds equation.