Patent ID: 8800995

Claim:
A mechanical seal device for sealing an interspace between a housing and a rotary shaft penetrating an aperture formed on said housing to seal fluid inside said housing, comprising: a rotary ring provided on said rotary shaft and having a seal surface at one end portion in the axial direction of said rotary shaft; a seal cover provided on the housing; a case fitted in an inner circumference surface of said seal cover; a stationary seal ring; a retainer on which the stationary seal ring is fitted; a bellows for elastically pressing said stationary ring toward said rotary ring via said retainer, an inside end portion of said bellows being connected to said case, an outside end portion of said bellows being connected to said retainer; the stationary ring provided in said retainer and having a counter surface arranged in a counter manner to said seal surface of said rotary ring, said stationary ring comprising a first seal surface circularly formed on said counter surface, said first seal surface sealingly contacting to and sliding on said seal surface of said rotary shaft, a second seal surface circularly formed on an outer circumference side or on an inner circumference side of said first seal surface of said counter surface in isolation from said first seal surface, said second seal surface sealingly contacting to and sliding on said seal surface of said rotary shaft, a sealing groove circularly formed in a part of said isolation between said first seal surface and said second seal surface, and a plurality of fluid passages formed inside of said stationary ring, one aperture of each of said fluid passages communicating to said sealing groove, and a quenching fluid supplying passage communicating to the second aperture of each of said fluid passages formed inside of said stationary ring, said quenching fluid supplying passage causing a flow of said quenching fluid into and/or from said sealing groove via said fluid passages, said quenching fluid supplying passage comprising an intermediate chamber formed in an inner circumferential portion of said seal cover, wherein said bellows separates said intermediate chamber and space on the seal fluid side, said intermediate chamber is surrounded by said seal cover, said case, said bellows, said retainer and said stationary ring, an interspace between said stationary ring and said seal cover is sealed by a seal member therebetween, the second aperture of each of said fluid passages in said stationary ring communicates to said intermediate chamber, so that said intermediate chamber and said sealing groove of said stationary ring is communicated by said plurality of fluid passages, and said first seal surface and said second seal surface of said stationary ring are formed as a duplex seal surfaces, one of them acting as a seal for sealing said seal fluid inside said housing from said quenching fluid in said sealing groove, the other acting as a seal for sealing said quenching fluid in said sealing groove against space outside of said housing.