计入变密度和变比热容的倾斜轴颈粗糙表面轴承润滑性能分析

Lubrication Performance Analysis of Misaligned Journal Bearing with Roughness Surface Considering Variable Density and Variable Specific Heat

计入变密度、变比热容以及轴颈倾斜等因素,对滑动轴承的热弹性流体动力润滑性能进行研究,深入分析变密度和变比热容对粗糙表面倾斜轴颈轴承热弹性流体动力润滑性能的影响。计算中,基于平均流量模型的广义Reynolds方程进行轴承的润滑分析,采用能量方程和热传导方程计算润滑油的温度场。结果表明,偏心率较大时,变密度和变比热容效应对轴颈倾斜轴承的承载力和最大油膜压力有较明显影响;计入变密度时,轴承最高油膜温度增加,摩擦功耗减小;计入变比热容时,轴承最高油膜温度减小,摩擦功耗增加;转速越高,变密度和变比热容对浮环轴承润滑性能的影响越显著;同时计入变比热容和变密度的轴承润滑参数与仅计入变比热容或仅计入变密度的润滑参数均有明显不同;间隙越小,变密度和变比热容对轴承润滑性能的影响越显著;为准确预测轴承的润滑性能,需同时考虑密度变化和比热容变化的影响。

The thermoelastrohydrodynamic lubrication performances of misaligned journal bearing considering surface morphology,thermal effect and variable density and variable specific heat are studied. The lubrication analysis of bearing is carried out by using average flow mode based generalized Reynolds equation. The temperature field is calculated by energy equation and heat conduction equation. The results show that the effects of variable density and variable specific heat on the bearing capacity and maximum film pressure of misaligned journal are obvious when eccentricity ratio is large. The maximum film temperature is increased and power loss is decreased when considering variable density. The maximum film temperature is decreased and power loss is increased when considering variable specific heat. The higher the speed is,the greater the effect of variable density and variable specific heat on the lubrication performance is. The lubrication parameters of bearing when considering variable density and variable specific heat are obviously different from those when considering variable density or variable specific heat. The smaller the clearance is,the greater the effects of variable density and variable specific heat on the lubrication performance. In order to accurately predict the lubrication performance of bearing,the influence of variable density and variable specific heat capacity need to be considered.