高速角接触轴承油气润滑两相流动特性数值研究

Numerical Investigation of Two-Phase Flow for the Oil-Air Lubrication Inside an Angular Contact Ball Bearing

针对油气润滑高速角接触球轴承腔内润滑冷却问题,提出了角接触球轴承油气两相润滑高精度数值计算模型。采用两相流模型和多重坐标系方法模拟轴承腔内两相流动特性;研究轴承运行工况及保持架几何参数对轴承腔内流场分布与换热效率的影响。结果表明:球形兜孔保持架轴承腔内的平均温度低于柱形兜孔保持架轴承,与实验结果相符。同时,过大或过小的兜孔间隙均会造成轴承腔内平均温度升高,因此合适的保持架兜孔结构与几何参数对于提高滚动轴承润滑性能至关重要。单个油气入口时,轴承腔内的润滑油分布并不均匀,在油气入口附近油相体积分数达到最大值;随着与入口位置距离的增加,油相体积分数逐渐降低。

A highly accurate model for angular contact ball bearing lubrication is proposed to investigate the performance of oil-air lubrication using the CFD （computational fluid dynamics） method.The MRF （multi-reference frame） method is adopted considering the complicated motion characteristics of the bearing.Comprehensive factors such as geometric features and bearing operating parameters are considered and discussed to provide guidelines for the optimization of lubrication and cooling efficiency.The influence of two types of cages on the lubrication is also analyzed.The results show that the average temperature inside the bearing with the spherical pockets cage is lower than that with the cylindrical pockets cage.The average oil volume fraction decreases when the clearance of the cage pockets increases and the temperature inside the bearing is lower when the clearance of the cage pockets is proper.The distributions of lubricant and temperature are not uniform inside the bearing cavity.The average oil volume fraction and the average temperature inside the bearing cavity decrease when the rotating speed increases.