| 摘要 |
PROBLEM TO BE SOLVED: To provide a mechanical seal capable of suppressing degradation of sealing performance between a stationary seal ring and a rotary seal ring even when pressure fluctuation of a sealed fluid is large.SOLUTION: A stationary seal ring 6 of a mechanical seal 1 has a seal end face 6f formed on an opposite-side end face 6d of a stationary-side seal end face 6a. A collar 7 is externally fitted between an elastic member 5 and the stationary seal ring 6 axially movably to a boss portion 4b of a retainer 4. The collar 7 is provided with an annular first seal face 7b opposed to an outer peripheral face of the boss portion 4b, and a second seal face 7c opposed to the seal end face 6f of the stationary seal ring 6. The mechanical seal 1 includes a seal ring 8 for sealing between the outer peripheral face of the boss portion 4b and the first seal face 7b of the collar 7, and further sealing between a seal end face 6f of the stationary seal ring 6 and the second seal face 7c of the collar 7. |
