Dynamic face seal arrangement

• US 6,007,068 A
• Filed: 11/25/1996
• Issued: 12/28/1999
• Est. Priority Date: 11/25/1996
• Status: Expired due to Fees

• Current Assignee: Department of Health and Human Services (State of Victoria)
• Original Assignee: US Government As Represented By The Director National Security Agency
• Inventors: Dellacorte, Christopher
• Primary Examiner(s): DePumpo, Daniel G.
• Application Number:
  US08/753,346
• Time in Patent Office: 1,128 Days
• Field of Search: 277/81 R, 277/82, 277/85, 277/88, 277/91, 277/96.2
• US Class Current: 277/361
• CPC Class Codes: F16J 15/366 and comprising vibration-damping means

Abstract

A radial face seal arrangement is disclosed comprising a stationary seal g that is spring loaded against a seal seat affixed to a rotating shaft. The radial face seal arrangement further comprises an arrangement that not only allows for preloading of the stationary seal ring relative to the seal seat, but also provides for dampening yielding a dynamic sealing response for the radial face seal arrangement. The overall seal system, especially regarding the selection of the material for the stationary seal ring, is designed to operate over a wide temperature range from below ambient up to 900° C.

Claims

1. In a radial face seal arrangement between high pressure and low pressure regions of fluid located along a rotating axial member having a metal seal seat mounted on said axial member for rotation therewith, the improvement comprising:

a stationary seal ring for sealably engaging said metal seal seat, said stationary seal ring having a face for engaging said seal seat and a rear portion and comprising a self-lubricating, friction and wear reducing material comprising about 60-80 percent by weight metal-bonded chromium carbide, 10-20 percent by weight soft noble metal, and 10-20 percent by weight metal fluoride mixture,

means for urging said stationary seal ring into engagement with said metal seal seat,

means for inhibiting a secondary leakage at said rear portion of said stationary seal ring, and

means for damping axial motion between said stationary seal ring and against said seal seat.

2. The radial face seal arrangement according to claim 1, wherein said stationary seal comprises a material comprising about 70 percent by weight metal-bonded chromium carbide, about 15 percent by weight silver, and about 15 percent by weight metal fluoride mixture.

3. The radial face seal arrangement according to claim 1, wherein said means for urging includes:

a spring for urging the stationary seal ring toward the seal seat thereby preloading the engagement of said stationary seal ring with said seal seat, and

an adjustable threaded collar for changing the position of said spring relative to said stationary seal ring which, in turn, changes the preloading of said stationary seal ring with respect to said seal seat.

4. The radial face seal arrangement according to claim 3 further comprising a mating push pin interposed between said spring and said stationary seal ring.

5. The radial face seal arrangement according to claim 4, wherein a plurality of springs operates in conjunction with a corresponding plurality of mating push pins.

6. The radial face seal arrangement according to claim 5, wherein said springs and said mating push pins are each comprised of a superalloy.

7. The radial face seal arrangement according to claim 6, wherein said plurality of mating push pins are housed in a corresponding plurality of chambers.

8. The radial face seal arrangement according to claim 7, wherein said chambers are each filled with a lubricating grease.

9. The radial face seal arrangement according to claim 1, wherein said means for inhibiting comprises a bellows having one end connected and located in proximity with said rear portion of said stationary seal ring and its other end connected so that said bellows encloses a defined region.

10. The radial face seal arrangement according to claim 9, wherein said bellows is comprised of a superalloy.

11. A radial face seal arrangement for sealing a region where a rotating shaft passes through a housing, said sealing arrangement comprising:

(a) a seal seat mounted on said shaft for rotation therewith;

(b) a stationary seal ring for sealably engaging said seal seat, said stationary seal ring having a face for engaging said seal seat and a rear portion and comprising a material of about 60-80 percent by weight metal-bonded chromium carbide, 10-20 percent by weight soft noble metal, and 10-20 percent by weight metal fluoride mixture;

(c) means for urging said stationary seal ring into engagement with said metal seal seat; and

(d) means for damping axial motion of said stationary seal ring relative to said seal seat.

12. The radial seal arrangement according to claim 11 further comprising means for inhibiting a secondary leakage at said rear portion of said stationary seal ring.

13. The radial face seal arrangement according to claim 12, wherein said stationary seal ring is carried by a seal ring carrier.

14. The radial face seal arrangement according to claim 11, wherein said stationary seal comprises a material comprising about 70 percent by weight metal-bonded chromium carbide, about 15 percent by weight silver, and about 15 percent by weight metal fluoride mixture.

15. The radial face seal arrangement according to claim 13, wherein said means for urging includes:

a spring for urging the seal ring carrier that carries said stationary seal ring toward said seal seat; and

an adjustable threaded collar for changing the position of said spring relative to said stationary seal ring.

16. The radial face seal arrangement according to claim 15 further comprising a mating push pin interposed between said spring and said stationary seal ring.

17. The radial face seal arrangement according to claim 16, wherein a plurality of springs operates in conjunction with a corresponding plurality of mating push pins.

18. The radial face seal arrangement according to claim 17, wherein said springs and said mating push pins are each comprised of a superalloy.

19. The radial face seal arrangement according to claim 18, wherein said plurality of mating push pins are housed in a corresponding plurality of chambers.

20. The radial face seal arrangement according to claim 19, wherein said chambers are each filled with a lubricant.

21. The radial face seal arrangement according to claim 20, wherein said lubricant is in the form of a grease.

22. The radial face seal arrangement according to claim 20, wherein said lubricant is a solid.

23. The radial face seal arrangement according to claim 13, wherein said means for inhibiting comprises a bellows having one end connected and located in proximity with said rear portion of said stationary seal ring and its other end connected to said seal ring carrier.

24. The radial face seal arrangement according to claim 23, wherein said bellows is comprised of a superalloy.