Patent ID: 7654536

Claim:
A seal ring comprising: a first sealing face of a body for sealing a surface of one of two members which are assembled concentrically with and rotatably relative to each other; a second sealing face of the body for sealing a side wall face of an annular groove formed in the other of said two members; and a separate portion separated at one circumferential portion of the body, a relief of said body for keeping a part of the second sealing surface out of abutment against the side wall face of said annular groove on the side of said unsealing fluid, said relief being formed throughout a circumference of said second sealing face; said relief having a first portion located in a vicinity of said separate portion, a second portion spaced away from said separate portion, and a third portion located between said first portion and said second portion; said first portion of the relief having a first outer radius that is shorter than a second outer radius of the second portion of the relief, and the second sealing face having an outer radius longer than said second outer radius; and said third portion of the relief having a gradually changing third outer radius that is between the first outer radius and the second outer radius.