Patent ID: 9303767
Filing Date: 2016-04-05
CPC Classification: F01D,F16J

Claim Text:
1. A seal assembly, comprising: a housing; a shaft rotatably received in the housing with an annular gap between the shaft and the housing a seal ring mounted in an annular groove provided around an outer circumference of the shaft for sealing the annular gap between the shaft and the housing to hold fluid pressure of a sealing region configured to allow change in fluid pressure, the seal ring, in close contact to a side wall surface of the annular groove on the low pressure side that slides with respect to an inner peripheral surface of a shaft hole in the housing, the shaft inserted therethrough and including on an outer peripheral surface side, a recessed section provided centrally in a width direction and extending in a circumferential direction, and a pair of raised sections provided on both sides with the recessed section therebetween for sliding with respect to an inner peripheral surface of the shaft hole; the seal ring having a through hole provided to lead to a bottom surface of the recessed section from an inner peripheral surface side and to enable sealed fluid to be introduced into the recessed section from the inner peripheral surface side, is configured so that an effective pressure receiving area from the inner peripheral surface side that contributes to a force pressing against an inner peripheral surface of the shaft hole by the fluid pressure is narrower than an effective pressure receiving area from the inner peripheral surface side that contributes to a force pressing against a side wall surface of the annular groove on a low pressure side; and the seal ring being configured by combining a first divided body of a high pressure side and a second divided body of a low pressure side in an axial direction, and a dividing position between the first divided body and the second divided body being set so as to pass through a portion where the recessed section is provided, wherein a third fitted raised portion that projects directly facing the low pressure side in the axial direction and a third fitted recessed portion that recesses directly facing the high pressure side in the axial direction is alternatingly provided in plurality in the circumferential direction on the side wall surface side of the low pressure side on the first divided body; and a fourth fitted recessed portion that fits the third fitted raised portion recesses directly facing the low pressure side in the axial direction and a fourth fitted raised portion that fits the third fitted recessed portion projects directly facing the high pressure side in the axial direction is alternatingly provided in plurality in the circumferential direction on the side wall surface side of the high pressure side on the second divided body.