Transient Lubrication Characteristics and Wear Behavior in VL-Type Reciprocating Seals

Abstract V-Lip type (VL-type) reciprocating seals are widely used in critical applications such as aerospace and heavy machinery due to their superior sealing performance and durability. With increasingly extreme operating conditions, understanding the synergistic relationship between transient lubrication and the wear process in VL-type reciprocating seals is critical for preventing seal failure and ensuring long-term reliability. In this study, a transient mixed lubrication numerical model for VL-type reciprocating seals was established by comprehensively considering transient effects, fluid–structure interaction, lip wear, and temperature-dependent material properties. Based on a database of initial static contact pressure and contact width obtained through finite element analysis and neural networks, the time-varying characteristics of the liquid film evolution, contact characteristics, and wear behavior at the sealing interface during the outstroke and instroke under transient conditions with pressure and speed variations of 1–20 MPa and 10–700 mm·s−1. Furthermore, the influences of temperature-induced material property changes (–30–135 °C) on the instantaneous liquid film characteristics, wear depth, leakage, and frictional force were examined. The results show a sharp increase in contact stress and aggravated friction and wear at a low temperature of –30 °C, and an increase in leakage and a weakening pumping effect at a high temperature of 135 °C. The findings could provide a theoretical basis for the material selection and structural design of high-performance VL-type reciprocating seals.