组件温度对球轴承热冲击流变润滑特性的影响

Effects of Assembly Temperature on Thermal Reological Lubricating Performance with Load Impact in Ball Bearings

为了研究组件温度对球轴承热冲击流变润滑性能的影响,考虑轴承组件温度与供油温度之间的差异,采用Eyring剪稀流体建立了球轴承热冲击流变弹流润滑模型,利用多重网格方法与时变性、流变性和温度场的分析技术研究了组件温度对动态油膜热流变弹流润滑性能的影响,并对极端工况下的热失效现象进行分析.结果表明:滚动体温度越高,其油膜厚度及摩擦系数越小;在极端工况下,轴承内圈与滚动体之间出现了高压、高温和低膜厚现象;轴承内圈温度达到边界膜脱附时的第1临界温度,且轴承内圈与滚动体之间处于混合润滑状态.因此,分析滚动轴承的非稳态热流变弹流润滑特性时需考虑轴承温度场的影响.

In order to investigate effects of assembly temperature on thermal reological lubricating performance with load impact in ball bearings,by using the Eyring shear-thinning fluid,a thermal reological elastohydrodynamic lubrication(EHL) model with a load impact in ball bearings was established.The model considered differences of the temperature between the assembly and the supplied oil.Multi-grid method and the numerical technique for time-dependent,reology and temperature field were used.Effects of the assembly temperature on the thermal reological lubricating performance of the dynamic oil film were investigated,and phenomena of thermal failure at extreme cases were analyzed as well.Results show that,differring from the convertional solution,the assembly temperature has much more influence on thermal EHL performance of the dynamic oil film.The higher the temperature of the ball,the less the film thickness and the frictional coefficient.At extreme cases,phenomena of high pressure,high temperature,and thin film appear for a bearing inner race-rolling element contact. Moreover,the temperature of the bearing inner race is up to the first critical temperature of desorption for the boundary film.In addition,the bearing inner race-ball contact is in a state of mixed lubrication.Therefore,effects of the temperature field in ball bearings should be considered in analysis of non-steady state thermal reological EHL.