| 摘要 |
A seal assembly between relatively rotating parts has chambers 20, 22 and 24 interposed between labyrinth seals 12, 14 and 16, and a face type seal 18. Fluid leaking through the seal 12 is accumulated in the chamber 20 and is maintained at a predetermined pressure by a vent 21. Some of the fluid in the chamber 20 leaks through the seal 14 into the chamber 22. To prevent leakage of fluid beyond the chamber 22, a purge fluid is introduced through an inlet 26 into the chamber 24 and leaks through the seal 16 into the chamber 22. The pressure of the purge fluid is greater than the fluid pressure in the chamber 22, but less than the fluid pressure in the chamber 20. An outlet conduit 28 serves to drain fluid from the chamber 22. <IMAGE> |
