Seal ring

Abstract

The present invention provides a seal ring capable of maintaining excellent low torque generation performance for a long term. A seal ring () is mounted on an annular groove formed on one member consisting of either a housing having a shaft hole or a rotary shaft inserted into the shaft hole, partly projects from the annular groove and contacts a surface of other member consisting of either the housing or the rotary shaft, and slidably contacts a side wall surface of the annular groove at a non-sealed fluid side thereof, thereby sealing an annular gap between the one member and the other member. An outer diameter side () of the side surface () of the ring to be subjected to at least the side wall surface of the annular groove is formed as an inclined surface having an inclined angle in such a way as to decrease a width of the ring from the outer diameter side of the side surface of the ring to an inner diameter side of the side surface thereof. A concave portion () which does not contact the side wall surface of the annular groove and communicates with an inner circumferential surface () of the ring is formed on a portion of the inner diameter side () of the side surface of the ring not projecting from the annular groove.