考虑唇口温度变化时的油封摩擦学性能研究

Study of tribological properties of the seal considering the change of lip temperature

文章针对径向唇形密封圈,研究了唇口形变和润滑油黏温效应,得到了与油封唇口温度相关的油膜厚度表达式,建立了油封唇口温度的二维轴对称数值模型,通过理论分析与数值模拟得到了唇口温度变化时的油封摩擦学性能。结果表明:转速对油封唇口与旋转轴之间的摩擦系数、油膜厚度和摩擦扭矩的影响较小,而唇口最高温度会随转速线性增加;随周向载荷增加,摩擦系数减小,摩擦扭矩与唇口最高温度逐渐增加;唇口温度的增加使润滑油黏度降低,导致油膜厚度减小;当以临界膜厚判定润滑失效时,可得出油封设计所需周向载荷等参数的取值范围。

Considering lip deformation and lubricating oil thermo-viscosity effect for radial lip seal, the expression of oil film thickness related to seal lip temperature is derived. And then the two-dimension- al axisymmetric numerical model of seal lip temperature is built. Tribological properties of the seal with the change of lip temperature are gotten by theoretical analysis and numerical simulation. The re- suits show that the speed has little impact on friction coefficient, oil film thickness and friction torque between seal lip and shaft. Moreover, the maximum temperature of the seal lip increases linearly with the increase of shaft speed. With the increase of circumferential load, the friction coefficient decrea- ses, and the friction torque and lip maximum temperature increase. The viscosity of engine oil decrea- ses with the increase of lip maximum temperature, which makes the thickness of oil film decrease. When the lubrication failure decided by the critical film thickness appears, the selection range of pa- rameters related to the design of oil seal such as circumferential load is obtained.