Non-contacting seals for geared gas turbine engine bearing compartments

Patent metadata

Field	Value
Publication number	US-9574459-B2
Application number	US-201414243003-A
Country	US
Kind code	B2
Filing date	Apr 2, 2014
Priority date	Mar 7, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A gas turbine engine includes a fan, a compressor section, a combustor, and a turbine section. The engine also includes a rotating element and at least one bearing compartment including a bearing for supporting the rotating element, a seal for resisting leakage of lubricant outwardly of the bearing compartment and for allowing pressurized air to flow from a chamber adjacent the seal into the bearing compartment. A method and section for a gas turbine engine are also disclosed.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
a fan, a compressor section, a combustor, and a turbine section;
a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing pressurized air to flow from a chamber adjacent said seal into the bearing compartment;
said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and
wherein said bearing compartment has a seal associated with each of two opposed axial ends, on either axial side of said bearing.

2. The gas turbine engine as set forth in claim 1 , wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said faces and into the bearing compartment to resist leakage of lubricant from the bearing compartment.

3. The gas turbine engine as set forth in claim 2 , wherein said seal being formed with a plurality of passages to allow tapping of additional pressurized air to be delivered to the faces at a location in the proximity of the grooved area for generating hydrostatic lift-off forces.

4. The gas turbine engine as set forth in claim 3 , wherein said grooved area is spaced radially from said plurality of passages at said seal face.

5. The gas turbine engine as set forth in claim 4 , wherein each of said plurality of passages is positioned radially outward of said grooved area.

6. The gas turbine engine as set forth in claim 5 , wherein said rotating element is a shaft rotating with a rotor having an axial face facing said seal face.

7. The gas turbine engine as set forth in claim 6 , wherein said grooved area is formed in said rotor.

8. The gas turbine engine as set forth in claim 7 , wherein said turbine section includes a fan drive turbine driving said fan through a gear reduction, said rotating element being driven by the fan drive turbine, and said at least one bearing compartment being associated with said gear reduction.

9. The gas turbine engine as set forth in claim 8 , wherein said seal is a carbon seal.

10. The gas turbine engine as set forth in claim 1 , wherein said rotating element is a shaft rotating with a rotor having a circumferential face facing said seal face.

11. The gas turbine engine as set forth in claim 10 , wherein said seal face faces radially inwardly.

12. The gas turbine engine as set forth in claim 11 , wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said faces and into the bearing compartment to resist leakage of lubricant from the bearing compartment.

13. The gas turbine engine as set forth in claim 12 , wherein said grooved area is formed in said rotor.

14. The gas turbine engine as set forth in claim 13 , wherein said seal is a circumferentially segmented carbon seal.

15. The gas turbine engine as set forth in claim 11 , wherein said seal is a controlled gap carbon seal having a full hoop seal and a metal band shrunk fit onto the seal, and positioned in a seal carrier.

16. The gas turbine engine as set forth in claim 15 , wherein the rotating element is driven by a fan drive turbine, and said at least one bearing compartment being associated with a gear reduction for driving the fan.

17. A method of designing a section of a gas turbine engine, the method comprising the steps of:
(a) configuring a bearing compartment to include a bearing designed to support a rotating element;
(b) configuring said rotating element to define a rotating face, said rotating face configured to rotate with said rotating element;
(c) configuring said bearing compartment to include a seal designed to resist leakage of lubricant outwardly of said bearing compartment and to allow air to flow from a chamber adjacent said seal and into said bearing compartment;
(d) configuring said seal to define a seal face facing said rotating face;
(e) designing said seal to be a non-contact seal; and
(f) configuring said bearing compartment to have a seal associated with each of two opposed axial ends, on either axial side of said bearing.

18. The method as recited in claim 17 , comprising the step of:
designing said faces to define a grooved area in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said faces and into said bearing compartment to resist leakage of lubricant from said bearing compartment.

19. The method as recited in claim 18 , wherein said rotating element is designed to be a shaft rotating with a rotor having an axial face facing said seal face.

20. The method as recited in claim 19 , wherein said grooved area is formed in said rotor.

21. The method as recited in claim 18 , comprising the step of:
designing said seal to define a plurality of passages to allow tapping of additional pressurized air to be delivered to said faces at a location in the proximity of said grooved area for generating hydrostatic lift-off forces.

22. The method as recited in claim 17 , wherein said rotating element is designed to be a shaft rotating with a rotor having a circumferential face facing said seal face.

23. The method as recited in claim 17 , wherein said seal is designed to be a controlled gap carbon seal having a full hoop seal and a metal band shrunk fit onto the seal, and positioned in a seal carrier.

24. A section for a gas turbine engine comprising:
a rotating element;
at least one bearing compartment configured to be secured to a static structure, said at least one bearing compartment including a bearing for supporting said rotating element;
a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing pressurized air to flow from a chamber across said seal into the bearing compartment, said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and
wherein said bearing compartment has a seal associated with each of two opposed axial ends, on either axial side of said bearing.

25. The section as set forth in claim 24 , wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said faces and into the bearing compartment to resist leakage of lubricant from the bearing compartment.

26. The section as set forth in claim 25 , wherein said seal is formed with a plurality of passages to allow tapping of additional pressurized air to be delivered to the faces at a location in the proximity of the grooved area for generating hydrostatic lift-off forces.

27. The section as set forth in claim 24 , wherein said rotating element is a shaft rotating with a rotor having an axial face facing said seal face.

28. The section as set forth in claim 24 , wherein said rotating element is a shaft rotating with a rotor having a circumferential face fa

Assignees

• United Technologies Corp

Inventors

• Ullah M Rifat
• Peters Robert E

Classifications

• F01D25/22

  using working-fluid or other gaseous fluid as lubricant · CPC title

• F01D25/186 Primary

  for sliding contact bearing · CPC title

• Y02T50/671

  Cross-Sectional Technologies · mapped topic

• F16J15/3412

  with cavities (F16J15/3424 takes precedence) · CPC title

• F01D25/166 Primary

  Sliding contact bearing (gas bearings F01D25/22) · CPC title