考虑动态特性的角接触球轴承微观热弹流分析

Analysis of Micro-elastohydrodynamic lubrication of Angular Contact Ball Bearing Considering Dynamic Characteristics

建立角接触球轴承的几何和数学模型,综合考虑几种不同轴承材料的弹流润滑性能,求得套圈采用Si3N4、滚球体采用GCr15的角接触球轴承的热弹流润滑完全数值解。在此基础上,进一步考虑角接触球轴承的几项重要基本参数(密合度、钢球数目等)及接触角随轴向载荷的变化对弹流润滑性能的影响。对轴承在承受纯轴向载荷作用下的热弹流润滑完全数值解进行分析,求得在不同轴向载荷下的压力、膜厚及温度分布图。结果表明:套圈、滚球体材料均选用Si3N4和分别选用Si3N4、GCr15两种情况下,最小油膜厚度更大,同样工况下,后者滚球体表面温度更低;密合度的增大有利于润滑油膜的形成;滚球体数量越多,油膜整体压力越小,油膜厚度越大,滚球体、套圈及油膜温度越低;轴向载荷越大,轴承的实际工作接触角越大;接触角的变化对弹流润滑具有很大影响,在考虑了接触角随轴向载荷的变化后得知,接触角增大,油膜的最小膜厚增大,最大压力减小。

The geometrical and mathematical model of angular contact ball bearing are established. A thermal elastohydrodynamic lubrication full numerical solution is carried out when the inner ring and rolling sphere are made from Si3N4 and GCr15 after considering the lubrication performance of several different bearing steels. On the basis of it,the effect of angular contact ball bearings’ several essential parameters （marginal adaptation、number of steel ball etc） and variation of contact angular with axial force on lubrication performance are considered. After the thermal elastohydrodynamic lubrication analysis of angular contact ball bearing under pure axial force,the pressure、film thickness and temperature distribution under different axial force are acquired. Results show that minimum film thickness is thicker when the inner ring and rolling sphere are made from Si3N4 and GCr15, but the later temperature is lower. The larger of the alignment, the thicker of the lubrication film thickness. The whole pressure is lower, film thickness is larger and the temperature of rolling sphere is lower with the increasing of rolling balls. The actual working contact angular is increased with the axial force increasing. The changing of contact angular makes great influence on elastohydrodynamic lubrication, minimum film thickness increases and maximum pressure are lower after considering the changing of contact angular with the variation of axial force.