| 摘要 |
In order to provide a mechanical seal device, which is suitably used even under a condition that fluid pressure is frequently switched between a positive pressure and a counter pressure, a mechanical seal device comprising; a rotary ring 137 provided on a rotary shaft 113 so as to integrally rotate with the rotary shaft, and on which rotary ring side sliding face 139 that constitutes one face of dynamic seal surface 173 is formed, a stationary ring assembly 52 on which stationary ring side sliding face 54 that slides with the rotary ring side sliding face and constitutes the other surface of the dynamic seal surface is formed, a seal cover 22 which contains the stationary ring assembly on inner diameter side and supports the stationary ring assembly to move freely in an axial direction of the rotary shaft, a first O-ring 92 which is sandwiched by the seal cover and the stationary ring assembly in a radial direction of the rotary shaft to seal the first fluid, and a second O-ring 96 which is provided closer to outside of the apparatus than the first O-ring and which is sandwiched by the seal cover and the stationary ring assembly in the radial direction, to seal the second fluid, wherein a low-pressure chamber 193, which is sealed from the first fluid and the second fluid by the first O-ring and the second O-ring and which maintains continual pressure lower than the pressure of the first fluid and that of the second fluid, is formed between the first O-ring and the second O-ring, a first pressure acting diameter 100 is located, when viewed in the radial direction, on a second seal end 177 side which is an end of the dynamic seal surface at the second fluid side with respect to a first seal end 175 which is an end of the dynamic seal surface at the first fluid side, and a second pressure acting diameter is located, when viewed in the radial direction, on the first seal end side with respect to the second seal end is provided. |
