Patent ID: 6045138
Filing Date: 2000-04-04
Classification: F16J

Abstract:
A sealing device for sealing two relatively axially reciprocable members at an interface between a liquid and air comprising:an annular body fixed to one of said members and having a seal lip extending from said body and slidably contacting the other of said members,a pair of annular projections formed in axially spaced relation on a surface of said seal lip, said projections each having a free end slidably contacting a sliding surface of said other member and thereby forming an annular space between said projections and said sliding surface of said other member,said free end of said projection on an air side of said sealing device having a contact structure defined by convergent surfaces so disposed with respect to said sliding surface of said other member as to define a surface facing a space between said projections inclined at an angle .beta.2 with respect to said sliding surface of said other member and a surface facing oppositely from said space-facing surface at an angle .alpha.2 with respect to said sliding surface of said other member, said surfaces satisfying the relationship .beta.2>.alpha.2, andsaid free end of said projection on a liquid side of said sealing device having a contact structure defined by convergent surfaces so disposed with respect to said sliding surface of said other member that, when said other member is moved in a direction from said liquid side to said air side, a thickness of a liquid film formed between said projection on the liquid side and said sliding surface of said other member is made greater than a thickness of liquid film formed between the projection on said air side and said sliding surface of said other member.