考虑温度影响时具有表面纹理唇形油封的密封性能研究

基于弹流润滑理论和旋转轴密封的泵送机理,综合考虑密封唇表面粗糙度和表面纹理的影响,建立了油封密封区域的混合润滑数值模型.模型耦合了流体力学、变形分析、接触力学、温度能量守恒方程和黏温方程, 通过迭代求解数值方程,得到不同表面纹理(圆形、正方形、等边三角形)油封唇口的温度分布、不同转速下油封唇口的最高温度,对比分析了表面纹理对油封接触面温度的影响以及温度升高对油封泵吸率、油膜厚度、摩擦扭矩等密封性能的影响.结果表明:随着转速的增大,唇口最高温度线性递增,表面纹理明显提高了油封的唇部温度;油封工作时,摩擦面的温度从两侧向中间急剧递增,纹理区域温度明显升高,但3种纹理油封之间差异不具有统计学意义.温度升高导致3种纹理油封的泵吸率、油膜厚度、唇口密封压力下降,明显降低了油封的密封性能.

Investigation into sealing performance of lip seals with surface texture when considering temperature effect

Based on elastohydrodynamic lubrication theory and pumping mechanism of rotary shaft seal, a numerical mixed lubrication model of sealing area in an oil seal was established by comprehensively considering the influence of surface roughness and texture of seal lip. In the model, fluid mechanics, deformation analysis, contact mechanics, temperature and energy conservation equation and viscous-temperature equation are coupled. By solving the numerical equations iteratively, the temperature distributions in oil seal lips with different surface textures(circular, square, equilateral triangle)and the maximum temperatures of oil seal lip under different rotational speeds were obtained. The effects of surface texture on temperature of oil seal contact surfaces and the influences of temperature rise on the sealing performance of the oil sea such as pumping rate, oil film thickness, friction torque, etc were compared and analyzed. The results show that with the increase of rotational speed, the maximum lip temperature rises linearly, and the surface texture obviously raises the lip temperature. When the oil seal is working, the temperature of the friction surfaces rises sharply from both sides to the middle, and the temperature in the texture area increases noticeably, but there is no statistics significance between three textures. The temperature rise leads to a decrease in pumping rate, oil film thickness and lip sealing pressure in the oil seals with three textures, and significantly degrades their sealing perfor-mance.