Thermoelastohydrodynamic Mixed Lubrication of Combined Rod Seals Operating at High Pressures and Speeds: Mathematical Modeling and Numerical Analysis

Abstract

Thermoelastohydrodynamic (TEHD) mixed lubrication characteristics of a step-combined rod seal under high-pressure and high-speed conditions are analyzed in this article. A novel TEHD mixed lubrication model for combined rod seals is innovatively established from the perspective of “seal-film-rod” system for the first time. Parameterized studies are conducted to evaluate the thermal effect on seal behavior with the comparison of isothermal elastohydrodynamic (EHD) lubrication analysis. Numerical results show that the interface friction heat is quite remarkable and mainly concentrated on the sealing lip, especially in high pressure and speed cases. With the increasing sealed pressure or rod speed, the temperature rise becomes more obvious and has a more significant impact on the sealing performance. The excessively rising temperature will even exceed the melting point of the sealing material, causing thermal damage.