Gas turbine engine including a low pressure sump seal buffer source and thermally isolated sump

• US 20050235651A1
• Filed: 04/21/2004
• Published: 10/27/2005
• Est. Priority Date: 04/21/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Tiltman, Alan G., Morris, Mark C., Poon, Kin, Volkmann, Bradley A.
• Granted Patent: US 7,093,418 B2
• Time in Patent Office: Days
• US Class Current: 60/782
• CPC Class Codes: F01D 25/125 of bearings
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F02C 7/28 Arrangement of seals
• CPC Class Codes: F05D 2240/50 Bearings
• CPC Class Codes: F05D 2260/231 Preventing heat transfer
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A gas turbine engine is configured to use relatively cool, low pressure air discharged from a low pressure compressor to supply buffer air to lubrication sump seals. The engine is further configured such that the lubrication sump is thermally layered by isolating relatively hot, high pressure compressor air from the sump by utilizing a warm vent mixing cavity, which is located radially between of the hot high pressure compressor air and the cool buffer air, which is located in a buffer cavity between the vent cavity and the sump.

Claims

1. A gas turbine engine, comprising:

a housing;

a compressor section and a turbine section all mounted in flow series within the housing, the compressor section including at least a low pressure compressor and a high pressure compressor, each compressor having an air inlet and an air outlet;

a lubrication sump disposed between the compressor section and the turbine section, the lubrication sump adapted to receive a flow of lubricant;

one or more sump seals coupled to the lubrication sump; and

a buffer air supply passage having an inlet in fluid communication with the low pressure compressor air outlet and an outlet in fluid communication with the sump seals, whereby air from the low pressure compressor is used to buffer the sump seals to thereby substantially prevent lubricant from leaking from the lubrication sump.

2. The engine of claim 1, wherein:

the housing is configured to define the lubrication sump and is further configured to define a buffer cavity;

the sump seals are at least partially exposed to the buffer cavity; and

the buffer air supply passage outlet is in fluid communication with the buffer cavity.

3. The engine of claim 2, wherein:

the housing is further configured to define a vent cavity; and

the engine further comprises one or more vent seals disposed between the buffer cavity and the vent cavity, the vent seals configured to allow fluid flow at least from the buffer cavity to the vent cavity.

4. The engine of claim 3, wherein:

the sump seals comprise ring seals; and

the vents seals comprise labyrinth seals.

5. The engine of claim 3, wherein:

the housing is further configured to define a high pressure air cavity in fluid communication with the high pressure compressor air outlet; and

the engine further comprises one or more throttle seals disposed between the vent cavity and the high pressure cavity, the throttle seals configured to allow fluid flow at least from the high pressure cavity to the vent cavity.

6. The engine of claim 5, wherein:

the sump seals comprise ring seals; and

the vents seals comprise labyrinth seals; and

the throttle seals comprise labyrinth seals in series with either brush seals or finger seals.

7. The engine of claim 1, wherein the housing is configured to define the buffer air supply passage.

8. The engine of claim 1, wherein the buffer air supply passage comprises a tube that extends through at least a portion of the housing.

9. The engine of claim 1, wherein the sump seals comprise ring seals.

10. A gas turbine engine, comprising:

a low pressure compressor having an air inlet and an air outlet, the low pressure compressor coupled to receive a rotational drive force and operable, upon receipt thereof, to supply a flow of low pressure compressed air;

a high pressure compressor having an air inlet and an air outlet, the high pressure compressed air inlet in fluid communication with the low pressure compressor air outlet, to thereby receive at least a portion of the flow of low pressure compressed air therefrom, the high pressure compressor coupled to receive a rotational drive force and operable, upon receipt thereof, to supply a flow of high pressure compressed air;

a combustor coupled to receive at least a portion of the flow of high pressure compressed air and a flow of fuel and operable to supply a flow of combusted gas;

a high pressure turbine coupled to receive the flow of combusted gas and operable, upon receipt thereof, to supply the drive force to the high pressure compressor and to supply high pressure turbine exhaust;

a low pressure turbine coupled to receive the high pressure turbine exhaust and operable, upon receipt thereof, to supply the drive force to the low pressure compressor;

a lubrication sump disposed between the high pressure compressor and the high pressure turbine, the lubrication sump adapted to receive a flow of lubricant;

one or more sump seals coupled to the lubrication sump; and

a buffer air supply conduit having an inlet in fluid communication with the low pressure compressor air outlet and an outlet in fluid communication with the sump seals, whereby a portion of the flow of low pressure compressed air is used to buffer the sump seals to thereby substantially prevent lubricant from leaking from the lubrication sump.

11. The engine of claim 10, further comprising:

a housing that at least partially surrounds the high and low pressure compressors, the high and low pressure turbines, and the combustor,

wherein;

the housing is configured to define the lubrication sump and is further configured to define a buffer cavity,

the sump seals are at least partially exposed to the buffer cavity, and

the buffer air supply conduit outlet is in fluid communication with the buffer cavity.

12. The engine of claim 11, wherein:

the housing is further configured to define a vent cavity; and

the engine further comprises one or more vent seals disposed between the buffer cavity and the vent cavity, the vent seals configured to allow fluid flow at least from the buffer cavity to the vent cavity.

13. The engine of claim 12, wherein:

the sump seals comprise ring seals; and

the vents seals comprise labyrinth seals.

14. The engine of claim 12, wherein:

the housing is further configured to define a high pressure air cavity in fluid communication with the high pressure compressor air outlet; and

the engine further comprises one or more throttle seals disposed between the vent cavity and the high pressure cavity, the throttle seals configured to allow fluid flow at least from the high pressure cavity to the vent cavity.

15. The engine of claim 14, wherein:

the sump seals comprise ring seals; and

the vents seals comprise labyrinth seals; and

the throttle seals comprise labyrinth seals and either finger seals or brush seals.

16. The engine of claim 11, wherein the housing is configured to define the buffer air supply conduit.

17. The engine of claim 11, wherein the buffer air supply conduit comprises a tube that extends through at least a portion of the housing.

18. The engine of claim 10, wherein the sump seals comprise ring seals.

19. In a gas turbine engine including a low pressure compressor having an air inlet and an air outlet, a high pressure compressor, a turbine, and a lubrication sump having one or more sump seals, a method of buffering the sump seals, comprising:

supplying seal buffer air to the one or more sump seals from the low pressure compressor air outlet, to thereby buffer the sump seals.

20. The method of claim 19, further comprising:

supplying at least a portion of the seal buffer air to the turbine.

21. The method of claim 20, wherein the high pressure compressor includes an air inlet and an air outlet, and wherein the method further comprises:

mixing high pressure compressed air from the high pressure compressor air outlet with the portion of the seal buffer air being supplied to the turbine to produce a relatively warm air mixture that is then supplied to the turbine.

22. The method of claim 21, wherein the high pressure compressed air and the seal buffer air are mixed in a vent cavity, and wherein the method further comprises:

flowing a portion of the high pressure compressed air through one or more first seals into the vent cavity;

flowing the portion of the seal buffer air through one or more second seals into the vent cavity, to thereby produce the relatively warm air mixture therein; and

supplying the warm air mixture from the vent cavity to the turbine.

23. In a gas turbine engine including a low pressure compressor having an air inlet and an air outlet, a high pressure compressor having an air inlet and an air outlet, a turbine, and a lubrication sump, a method of thermally isolating the lubrication sump from air discharged from the high pressure compressor, comprising:

forming a buffer cavity that at least partially surrounds the lubrication sump;

forming a vent cavity that at least partially surrounds the buffer cavity disposing one or more vent seals between the buffer cavity and the vent cavity that are configured to allow leakage at least from the buffer cavity to the vent cavity;

disposing one or more throttle seals between the high pressure compressor air outlet and the vent cavity that are configured to at least allow leakage from the high pressure compressor air outlet to the vent cavity; and

supplying air to the buffer cavity from the low pressure compressor air outlet.