计及轴颈倾斜的径向滑动轴承湍流润滑分析

Analysis of Turbulent Lubrication of Misaligned Journal Bearing

分析了轴颈倾斜状态下,径向滑动轴承的湍流润滑性能.基于轴颈倾斜的统一Reynolds方程和能量方程,应用有限差分法求解了不同轴颈倾斜方位角、轴颈倾斜度、偏心率和平均雷诺数下的径向滑动轴承湍流润滑性能.结果表明:轴颈倾斜方位角α=0°时,随着轴颈倾斜度的增大,轴承油膜的压力峰向轴承一端移动,轴承一端的轴向油膜温度梯度增大;α=90°时,随着轴颈倾斜度的增大,轴承油膜压力逐渐出现双峰分布,且向轴承两端移动,轴承两端的轴向温度梯度也不断增大.在相同轴颈倾斜度增量下,轴承最大油膜压力、最高油膜温度、承载力和稳定工作力矩的增量随轴承中央截面偏心率的增大而增大.相同轴颈倾斜度增量下,轴承最大油膜压力增量、最高油膜温度增量、承载力增量、摩擦系数减量和稳定工作力矩增量随平均雷诺数的增大而增大.可见,径向滑动轴承湍流润滑分析中有必要考虑轴颈倾斜因素的影响.

The turbulent lubrication performance of misaligned journal bearing was analyzed.Based on the unified Reynolds equation and energy equation considering the misalignment of the journal,the finite-difference method was used to calculate the turbulent lubrication performance of the journal bearing under different misalignment azimuth,degree of misalignment(DM),eccentricity ratio and average Reynolds number.The results show that when the azimuth angle of the journal wasα=0°,the pressure peak of the bearing oil film moved toward the bearing end as the DM increased,and the axial oil film temperature gradient at one end of the bearing increased.When the azimuth angle of the journal wasα=90°,as the DM increased,the bearing oil film pressure distribution gradually appeared double peak,and moved to both ends of the bearing,the axial temperature gradient at both ends of the bearing also increased.When the DM was large,the increment of the maximum film pressure,the maximum oil film temperature,the load-carrying capacity and the misalignment moment increased with the increase of the eccentricity of the central section of the bearing under the same DM increment.Under the same DM increment,the Maximum film pressure increment,maximum film temperature increment,load-carrying capacity increment,frictional coefficient reduction and misalignment moment increment increased with the increase of average Reynolds number.Therefore,it’s necessary to consider journal misalignment in the turbulent lubrication analysis of journal bearing.