Carbon seal contaminant barrier system

• US 5,813,830 A
• Filed: 02/09/1996
• Issued: 09/29/1998
• Est. Priority Date: 02/09/1996
• Status: Expired due to Term

• Current Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc)
• Original Assignee: Allison Engine Company, Inc.
• Inventors: Black, Joseph D., Bowman, Mark E., Smith, Joseph C.
• Primary Examiner(s): KWON, JOHN
• Application Number:
  US08/599,028
• Time in Patent Office: 963 Days
• Field of Search: 415/170.1, 415/174.2, 415/174.5, 415/229, 415/230, 415/231, 277/192, 277/157, 277/152, 277/58
• US Class Current: 415/170.1
• CPC Class Codes: F05B 2220/301 in steam turbines
• CPC Class Codes: F16J 15/3488 Split-rings
• CPC Class Codes: F16J 15/442 segmented

Abstract

A carbon seal contaminant barrier system for a gas turbine engine including a lip seal for wiping the surface of a rotating seal runner, and a baffle spaced from the rotating seal runner to prevent the impingement of the contaminants on the lip seal. The lip seal and the baffle are spaced axially and cooperate to minimize the contaminants passed to a carbon sealing system. The circumferential carbon sealing ring having a plurality of passages therethrough for delivering pressurized gas adjacent the carbon sealing ring. The pressurized gas being utilized to reduce the drag on the lip seal and to reduce the migration of contaminants onto the carbon seal. The barrier system being utilized to reduce the contamination of the carbon seal and prevent the inherent leakages associated therewith and the potential contamination of the environmental system of the aircraft.

Claims

1. In combination:

a gas turbine engine;

a mechanical housing within said gas turbine engine;

a shaft rotatably mounted within said housing;

a carbon seal connected to said housing;

a seal runner connected to said shaft, said seal runner arranged adjacent to said carbon seal to form a substantially fluid tight seal therebetween;

a lip seal contacting said seal runner; and

a baffle spaced from said lip seal and positioned around said seal runner.

2. The combination of claim 1, wherein a portion of said lip seal rides on the outer surface of said seal runner to wipe contaminants away.

3. The combination of claim 2, wherein said lip seal has a l shaped portion.

4. The combination of claim 2, wherein said baffle is spaced axially from said lip seal and radially from said seal runner, and wherein said baffle for minimizing the direct impingement of excited fluid on said lip seal.

5. The combination of claim 2, wherein said baffle is formed of sheet metal and has anti-rotation means for preventing rotation of the baffle relative to said housing.

6. The combination of claim 1, which further includes an annular radial passageway between said baffle and said seal runner leading into an annular cavity around said seal runner, said annular radial passageway being smaller than said annular cavity.

7. The combination of claim 6, wherein said baffle has an opening therein for allowing fluid drainage from said annular cavity.

8. The combination of claim 6, wherein said annular cavity for retaining fluids to cool said lip seal.

9. The combination of claim 1, which further includes means for discharging pressurized gas against said lip seal for reducing the load on said shaft.

10. The combination of claim 1, wherein said carbon seal and said seal runner are axially concentric, and wherein said surface disposed adjacent each other for forming said substantially fluid tight seal.

11. The combination of claim 10, wherein said carbon seal is defined by an arcuate carbon ring.

12. The combination of claim 11, wherein said seal runner has a circumferential cooling channel formed thereround.

13. In combination:

a gas turbine engine;

a mechanical housing within said gas turbine engine;

a shaft rotatably mounted within said housing;

a first sealing element coupled to said housing;

a second sealing element connected to said shaft, said second sealing element arranged adjacent to said first sealing element to form rubbing interface therebetween; and

a passageway for the delivery of a pressurized gas adjacent said first sealing element to reduce the impingement of a contaminant onto said first sealing element.

14. The combination of claim 13, wherein at least a portion of said passageway along said shaft.

15. The combination of claim 14, wherein said first sealing element is a carbon sealing element and said second sealing element is a seal runner.

16. The combination of claim 15, wherein said carbon seal and said seal runner are axially concentric, and wherein said seal runner and said carbon seal each have a cylindrical surface disposed adjacent each other for forming said rubbing interface.

17. The combination of claim 14, wherein said carbon sealing element has a channel formed therein for fluid flow.

18. The combination of claim 17, wherein said channel is formed substantially circumferential.

19. The combination of claim 17, wherein said carbon sealing element has a radially extending path for allowing the discharge of pressurized gas to the other surface of said seal runner.

20. The combination of claim 19, wherein said carbon sealing element is defined by a plurality of arcuate adjoining members, and wherein said radially extending path is formed between a pair of said plurality of arcuate adjoining members.

21. In combination:

a gas turbine engine;

a mechanical housing within said gas turbine engine;

a shaft rotatably mounted within said housing;

a first sealing element coupled to said housing;

a second sealing element connected to said shaft, said second sealing element arranged adjacent to said first sealing element to form rubbing interface therebetween;

a third sealing element positioned adjacent said second sealing element for substantially reducing the flow of a contaminant to said first sealing element; and

a baffle connecting to said housing and positioned radially from said second sealing element for reducing the impingement of the contaminant on said third sealing element.

22. The combination of claim 21, wherein said third sealing element is a windback.

23. The combination of claim 22, wherein said windback has only one thread.

24. The combination of claim 22, wherein said first sealing element is a carbon seal and said second sealing element is a seal runner, said carbon sealing element and said seal runner being axially concentric.

25. The combination of claim 22, wherein:

said windback has only one thread;

which further includes an annular radial passageway between said baffle and said second sealing element leading to an annular cavity disposed around said second sealing element, said annular radial passageway being smaller than said annular cavity;

said baffle formed of sheet metal and further including an opening therethrough for the passage of fluid from said annular cavity during shut down of said gas turbine engine; and

said first sealing element is a carbon seal and said second sealing element is a seal runner, said carbon sealing element and said seal runner are axially concentric.

26. The combination of claim 21, which further includes an annular radial passageway between said baffle and said second sealing element leading to an annular cavity disposed around said second sealing element, said annular radial passageway being smaller than said annular cavity.

27. The combination of claim 26, wherein said baffle is sheet metal, and said baffle further including an opening therethrough for the drainage of fluid said annular cavity during the shut down of said gas turbine engine.

28. In combination:

a gas turbine engine;

a mechanical housing within said gas turbine engine;

a shaft rotatably mounted within said housing;

a first sealing element coupled to said housing;

a second sealing element connected to said shaft, said second sealing element arranged adjacent to said first sealing element to form rubbing interface therebetween; and

a lip seal arranged adjacent said first sealing element to form a rubbing interface with said second sealing element, said lip seal wiping the outer surface of said second sealing element to reduce the flow of a fluid to said first sealing element.

29. The combination of claim 28, which further includes a passageway around said second sealing element and in fluid communication with said lip seal, said passageway having a narrowed portion for calming the flow of fluid prior to impingement upon said lip seal.

30. The combination of claim 28, wherein said first sealing element is a carbon seal and said second sealing element is a seal runner, said carbon sealing element and said seal runner being axially concentric.

31. The combination of claim 30, wherein said lip seal having a l shaped portion.

32. The combination of claim 31, wherein wherein said lip seal has pressurized gas discharged thereagainst for reducing said lip seal'"'"'s load on said shaft.

33. The combination of claim 28, wherein said third sealing element is windback.

34. The combination of 33, wherein said windback having about one thread.

35. In combination:

a gas turbine engine;

a mechanical housing within said gas turbine engine;

a shaft rotatable within said housing;

a carbon sealing element coupled to said housing;

a seal runner coupled to said shaft and being positioned adjacent said carbon sealing element to form a substantially fluid tight seal therebetween; and

an annular member spaced from said carbon sealing element and around said seal runner so as to limit the passage of contaminants to said carbon seal without causing contaminants to be pulled back into said carbon seal.