Bai Shaoxian, Chen Yangyang, Yang Jing
College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
Materials (Basel). 2024 Jul 21;17(14):3600. doi: 10.3390/ma17143600.
Friction and wear are the main failure sources of face seals. When the surfaces of sealing rings exhibit greater roughness, the level of friction might increase and lead to sealing failure. Therefore, in this paper, based on the elastic contact hypothesis of rough and wavy surfaces and the influence of temperature on the elastic modulus of materials, a thermoelastic contact lubrication model of a gas-lubricated end seal is established. The novelty and advantage of this study is that it takes the effect of surface roughness into consideration during thermoelastic analysis of gas-lubricated seals. The film pressure, temperature, contact force and deformation of a gas spiral groove-faced seal are numerically determined. The influence of surface roughness on the contact distribution, deformation and temperature of the end-face seal at different speeds and pressures is analyzed. The film thickness increases as the rotational speed increases from 1 rpm to 2000 rpm, while the contact pressure sharply decreases from 0.25 kPa to 0. The analysis shows that the roughness contact mainly happens on the inner side of the rings due to convergent distortion of the seal faces, which easily causes partial wear of the seal faces. Moreover, it can also be found that the spiral grooves on the sealing surface can produce obvious hydrodynamic pressure effect due to the function of shear speed when the speed increases to 2000 rpm, while the film temperature increases from 293.3 K to about 306 K. The greater surface roughness results in a larger temperature rise under low-rotational-speed and lower-seal-pressure conditions, which further increases the risk of severe wear or even failure of the seal faces.
摩擦和磨损是端面密封的主要失效源。当密封环表面粗糙度较大时，摩擦力可能会增加并导致密封失效。因此，本文基于粗糙和波浪形表面的弹性接触假设以及温度对材料弹性模量的影响，建立了气体润滑端面密封的热弹性接触润滑模型。本研究的新颖之处和优势在于，在气体润滑密封的热弹性分析中考虑了表面粗糙度的影响。数值确定了气体螺旋槽端面密封的膜压力、温度、接触力和变形。分析了表面粗糙度在不同速度和压力下对端面密封的接触分布、变形和温度的影响。当转速从1转/分钟增加到2000转/分钟时，膜厚增加，而接触压力从0.25千帕急剧降至0。分析表明，由于密封面的收敛变形，粗糙度接触主要发生在密封环的内侧，这很容易导致密封面的局部磨损。此外，还可以发现，当速度增加到2000转/分钟时，密封面上的螺旋槽由于剪切速度的作用会产生明显的流体动压效应，而膜温度从293.3开尔文升高到约306开尔文。在低转速和低密封压力条件下，较大的表面粗糙度会导致更大的温度升高，这进一步增加了密封面严重磨损甚至失效的风险。
