BI-MODULUS COMPOSITE SEAL AND ITS METHOD OF MANUFACTURE

摘要

A lip-type fluid seal (10) for a shaft includes a composite sealing lip (26) having an elastomeric portion (32) and a PTFE portion (36). The elastomeric portion (32) includes a lip edge (33) that extends circumferentially continuously to seal the adjacent lip edge (37) of the PTFE portion (36) fro m any contaminants on the elastomeric side (28) of the seal (10). The PTFE portion (32) has a greater hardness and modulus of elasticity which serves t o limit the wear of the elastomeric portion (32) and to induce hydrodynamic surface deformations on the elastomeric lip portion (32) during operation to enhance the exclusion of contaminants. The PTFE lip edge (37) performs well under low temperature and/or low lubricity conditions and its relative hardness protects the elastomeric lip edge from excessive wear.