Patent ID: 8720901

Claim:
A seal ring for installation into an annular groove formed on a shaft that seals an annular gap between the shaft and a housing that has a shaft hole into which the shaft is inserted, comprising: a ring-shaped body having a first end and a second end that are separated from each other by temporarily moving the first end and the second end away from each other during installation of the seal ring into the annular groove, and are attached when the seal ring is installed in the annular groove to thereby seal the annular gap; a projection formed on each of the first end and the second end that project in the direction of a circumference of the seal ring, the projections each having an outer surface defining an outermost peripheral surface coincident with an outermost surface of a remainder of said ring-shaped body, and having an inner surface that is concentric with said outer surface so that said projection has a generally equal width in a radial direction throughout its length; a recess formed on each of the first end and the second end that cooperates with the projections, wherein the projections and the recesses are fitted together while sliding against each other to thereby bring both the first and second ends into contact with each other; each of the recesses have a distal end and a proximal end spaced circumferentially from said distal end, the proximal end being located where the recess terminates at a first end that defines a first end face that extends substantially radially inward from the outermost surface of the ring body and the distal end being located where the recess terminates at a second end that defines a second end face that extends substantially radially inward toward an innermost surface of the ring body, and the recess including an inclining side face between the proximal end and the distal end, which continually inclines radially inward from the proximal end to the distal end in a direction of the circumference such that the distal end of the recess is expanded to a greater extent than the proximal end and to a greater extent than the width of the projection; the projection and the recess form a sliding part so that a part of an edge of the leading end of the inner surface of the projection slides over the inclining side face of the recess, and a portion of the sliding part is formed as a linear sliding portion; and as the projections are fitted together while sliding against each other, portions of the inner surfaces thereof are always spaced apart from the inclining side faces by a gap.