Research on Sealing Performance of Integral Modified PTFE Lip Seals

Abstract

Hydrogen circulation pumps in industrial manufacturing equipment face typical sealing challenges at the shaft end. Due to the small molecular diameter and high diffusivity of hydrogen, a single improvement approach cannot adequately enhance sealing performance. While previous studies have largely focused on material modification, systematic investigations into the influence of structural parameters remain limited. Lip radius, lip thickness, and contact lip width are key structural parameters governing sealing performance; however, systematic investigations into modified PTFE lip seals under hydrogen operating conditions remain scarce. To address this gap, this paper presents an integrally structured aluminum alloy skeleton modified PTFE lip seal and develops a finite element analysis model. In this model, the mechanical behavior of the modified PTFE is described using the bilinear isotropic hardening model, while the contact nonlinearity between the lip and the shaft is solved using the Newton–Raphson iterative method. The effects of structural parameters on sealing performance indicators, including maximum contact pressure, maximum friction stress, and shaft clamping force and torque, are systematically analyzed. The results indicate that reducing the lip radius, increasing the lip thickness, and increasing the contact lip width can effectively improve the sealing-related contact characteristics of the seal ring.