径向油孔结构对环下润滑高速轴承内部流动特性的影响研究

Effects of radial oil hole structure on internal flow characteristics of high-speed bearings with under-race lubrication

关键词:  高速轴承  环下润滑  径向油孔  油气两相流  流体黏性摩擦

Key words:  High-speed bearing  Under-race lubrication  Radial oil hole  Oil-gas two-phase flow  Fluid viscous friction

摘要:

为了研究径向油孔结构对环下润滑高速轴承内部流动特性的影响规律，根据高速轴承内部流动特征建立了数值计算方法，针对包含输油通道、径向油孔和轴承组件的物理仿真模型开展了油气两相流动计算，对比并讨论了不同径向油孔结构下轴承内部的油气分布和黏性摩擦损失。数值模拟结果表明，径向油孔孔径增大后轴承内部的平均滑油体积分数单调增加且滑油分布更均匀。径向油孔布设在周向油槽的同侧有利于提升轴承内部的平均滑油体积分数，同时滑油沿周向分布的均匀性较好。轴承组件表面扩展参数受径向油孔结构的影响，其变化趋势与平均滑油体积分数的变化相似。全部采用经验公式预测得到的黏性摩擦损失整体偏高，且不能反映径向油孔结构参数的影响，数值模拟和经验公式相结合计算得到的黏性摩擦损失与直接采用数值模拟获得的结果表现出较好的一致性。

Abstract:

To study the effects of radial oil hole structure on the internal flow characteristics of high-speed bearings with under-race lubrication， a numerical calculation method is established according to the internal flow characteristics of high-speed bearings. The oil-gas two-phase flow calculation is carried out for physical simulation models including oil passages， radial oil holes and bearing assemblies. The oil and gas distribution and viscous friction loss inside the bearing under different radial oil hole structures are compared and discussed. The numerical simulation results show that the average oil volume fraction inside the bearing increases monotonically and the oil distribution is more uniform when the radial oil hole diameter increases. The arrangement of radial oil holes on the same side of the circumferential oil groove is conducive to improving the average oil volume fraction inside the bearing， and the uniformity of the circumferential oil distribution is better. The surface spread parameters of bearing assembly are affected by the radial oil hole structure， and its variation trend is similar to that of the average oil volume fraction. The viscous friction loss predicted by the empirical formula is generally high， and the empirical formula cannot reflect the effects of the radial oil hole structure parameters. The viscous friction loss calculated by the combination of numerical simulation and empirical formula is in good agreement with the results obtained directly by numerical simulation.