SEAL STRUCTURE AND METHOD OF MANUFACTURING THE SAME

摘要

An annular space (7) is formed between a seal lip (41) of a rubber-like elastic material and a seal lip (51) of a resin so that the latter seal lip (51) does not interfere with the former seal lip (41), whereby the follow-up characteristics of the seal lip (51) of a resin with respect to a shaft and the sealability of a seal structure are improved. A plurality of annular parallel grooves (55) are formed in the side surface (54) of the seal lip (51) of a resin which faces the annular space, so as to increase the flexibility of the seal lip (51) and further improve the follow-up characteristics thereof with respect to a shaft. A flat washer-like PTFE sheet is inserted as it is in a mold, and adhesion-bonded to a first rubber seal member simultaneously with a rubber vulcanization molding operation. A plurality of annular grooves and helical grooves are formed in the PTFE sheet by utilizing a mold clamping pressure, and the molded PTFE sheet is subjected to bending at the time of releasing from the mold. The seal structure manufacturing steps can thus be reduced.