To avoid contact between an inner peripheral surface of seal ring main body with a rotary shaft by forming a cutout on a low pressure side end face of the seal ring main body from the outer peripheral side, reducing the pressing force applied to the seal ring against the ring groove end face, and thereby reducing frictional force.
Axially applying pressure distribution is obtained at high pressure and low pressure side end faces 15a, 15b of a seal ring 14. The seal ring 14 is pressurized against a high pressure side end face 13a of a ring groove by the pressure distribution. Since a cutout 16 is formed on the low pressure side end face 15b from the outer peripheral side for balancing pressure, however, the pressing force F is remarkably reduced compared to the conventional case without the cutout 16. The frictional force μF generated when the seal ring 14 is moved by floating force W is reduced, facilitating the movement of the seal ring 14. It is thus possible to avoid contact between an inner periphery of the seal ring 14 and a rotary shaft 12.
MATSUI AKIHIKO
TAKEMOTO YOSHIAKI
