Patent ID: 10139003

Abstract:
Disclosed is a lip seal for water pump made of a rubber-like elastic material, fixed to a housing as a fixed side and in sliding contact with a shaft rotating relative to the housing; the lip seal having sliding surface with a surface roughness Ra (according to JIS B0601 corresponding to ISO 4287) of 1 to 30 μm, being obtained by vulcanization-molding of a rubber composition comprising 100 parts by weight of the rubber-like elastic material, 1 to 150 parts by weight of a reinforcing filler, 5 to 90 parts by weight of a non-reinforcing filler having an average particle diameter of 1 μm or more, 0.1 to 5 parts by weight of a coupling agent, 1 to 15 parts by weight of a co-crosslinking agent, and 0.5 to 10 parts by weight of an organic peroxide. The lip seal effects to prevent softening and volume swelling of the rubber-like elastic material and furthermore the generation of deposits in the rotating shaft, which are problematic for rotation torque and LLC resistance.