Nok Corporation

Naohiro Jotaki

Shinya Nakaoka

Nobuyuki Eguchi

Takaaki Yasudomi

Provided is a sealing apparatus which can reduce the torque of a rotary portion while always exhibiting a stable and high sealing performance even when a high fluid pressure is being applied. A seal ring () inclines when subjected to a hydraulic pressure (P) and a pressing force by a D-ring (), and stabilizes in a state where an entire opposite pressure-side taper surface () is in contact with an opposite pressure-side side surface () of an annular groove for sealing (). With the hydraulic pressure (P) being applied to a portion () of the inner peripheral surface () of the seal ring () where an operating oil comes into contact, a space between the portion () and a shaft () is enlarged, and an area of contact between the seal ring () and the shaft () is reduced. Thus, the torque can be reduced. Furthermore, since the outer peripheral surface () of the D-ring () is a surface having a cylindrical shape, the operating oil is not allowed to enter between the D-ring () and a bottom surface () of the annular groove for sealing () even when the hydraulic pressure (P) is being applied, and the entirety of the outer peripheral surface () of the D-ring () always remains in contact with the bottom surface () of the annular groove for sealing (). Thus, the sealing device always exhibits a stable sealing performance.

Sealing apparatus

A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion to the other side thereof, and the linear contact part provided at the convex part of the separation portion, and the linear contact part provided at the concave part of the separation portion are located at a distance in the radial direction of the seal ring.

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Tokyo, Japan

Naohiro Jotaki