Abstract: A method of fabricating a fluid seal for sealing a relatively rotatable member, wherein the fluid seal has an elastomeric sealing member bonded to a PTFE insert. A wafer of PTFE material has a body portion and an end portion of a greater thickness than the body portion. The wafer is placed in a mold cavity with one side of the wafer opposed to a surface portion of the mold cavity. Elastomeric material is forced into the mold cavity to form a molded preform of the elastomeric sealing member and bond the preform to an opposite side of the wafer. The molded preform and bonded wafer are removed from the mold cavity. The end portion of the wafer and an end portion of the preform are trimmed to form the fluid seal.

Abstract: 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) from 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 to 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.