Patent ID: 7918463
Filing Date: 2011-04-05
Classification: F16F,F16J

Abstract:
1. A reciprocating seal provided in an annular space formed between a shaft and a housing, which move relatively to each other in a direction of the shaft, said reciprocating seal comprising a seal lip brought into sliding contact with a surface of the shaft, the seal lip having a two-step lip structure including a first step and a second step, a sub seal lip in sliding contact with the surface of the shaft, the second step being closer to the sub seal lip than said first step, the first step and the second step each having a first inclined surface and a second inclined surface relative to a longitudinal axis of the shaft, the first inclined surface of the first step and the second step being spaced further from the sub seal lip than the second inclined surface of the first step and the second step, the first inclined surface and the second inclined surface of the second step being separated by an apex of the second step, and a plurality of protrusions extending in a direction parallel to the longitudinal axis of the shaft and said plurality of protrusions extending in a direction perpendicular to the apex of the second step, said plurality of protrusions being formed on only the second inclined surface of the second step, said plurality of protrusions being equally spaced along an entire length of the protrusions.