Patent ID: 9574667
Date: 2017-02-21
CPC Classifications: F16J

Claim:
1. A mechanical seal device for sealing a sealed fluid inside of a machine at a space formed between a device main body and a rotary shaft, comprising: a seal case attached to the device main body, a rotary seal ring attached to the rotary shaft, a stationary seal ring arranged in an axial direction opposing to the rotary seal ring, a bellows attached extendably in the axial direction between the stationary seal ring and the seal case, the bellows applying compressive force pressing the stationary seal ring toward the rotary seal ring, a resilient member pressing the stationary seal ring toward the rotary seal ring, a static pressure fluid supplying hole, formed on the seal case, supplying a static pressure fluid to a static pressure fluid chamber arranged at an inner circumferential side of the bellows, and a seal member, arranged between the seal case and the stationary seal ring at the inner circumferential side of the bellows, holding the stationary seal ring movably in the axial direction and sealing the static pressure fluid chamber from an atmosphere side space, wherein communication holes are formed on the stationary steel ring extending from the static pressure fluid chamber, and guiding the static pressure fluid of the static pressure fluid chamber between a sealing surface of the stationary seal ring and a sealing surface of the rotary seal ring, an annular groove connecting each communication hole is formed on the stationary seal ring, an outer diameter of the annular groove is designed so that it is essentially equal to a pressure acting diameter of the bellows, an inner diameter of the annular groove is designed so that it is essentially equal to a contact diameter where the seal member contacts the stationary seal ring, and the sealed fluid is arranged at an outer circumferential side of the bellows.