Patent ID: 7341256

Claim:
A seal ring comprising: a first seal portion which seals a sidewall surface of an annular groove on an unsealed fluid side of a shaft, the annular groove being provided in one of two members that are concentrically assembled so as to be relatively rotatable; a second seal portion which seals a surface of the other of the two members, an annular interspace between the two members being sealed by the first and second seal portions, a ring body with a separation portion separated in one place in a circumferential direction to include a first end part and a second end part, said first seal portion being provided with linear contact portions which come into linear contact with the sidewall surface of the annular groove on the unsealed fluid side, so as to extend continuously over a whole circumference of the seal ring from one side of said separation portion to the other side thereof, and said linear contact portion which is provided on one side of said separation portion, and said linear contact portion which is provided on the other side of said separation portion being located at a distance in a radial direction of the seal ring so that an inner circumferential surface of the first end part on one side of the separation portion comes into contact with an outer circumferential surface of the second end part on the other side of the separation portion and said linear contact portions having a narrower width in the radial direction than adjacent parts of the ring body to control a quantity of leakage from a sealed fluid side to the unsealed fluid side of the shaft; and wherein said linear contact portions include: a first linear contact portion which is extended continuously from one side of said separation portion to the other side thereof, and which comes into linear contact with the sidewall surface of the annular groove on the unsealed fluid side; and a second linear contact portion which lies nearer a groove bottom side of the annular groove than said first linear contact portion, which is extended continuously from one side of said separation portion to the other side thereof, and which comes into linear contact with the sidewall surface of the annular groove on the unsealed fluid side, said linear contact portion provided on one side of said separation portion is said first linear contact portion, while said linear contact portion provided on the other side of said separation portion is said second linear contact portion.