Integrated gearless and nonlubricated auxiliary power unit

• US 7,251,942 B2
• Filed: 06/29/2004
• Issued: 08/07/2007
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Schenk, Bjoern, Sheoran, Yogendra Y., Dittmar, Kevin S., Edmonds, David H.
• Primary Examiner(s): KIM, TAE JUN
• Application Number:
  US10/880,820
• Publication Number:
  US 20050284150A1
• Time in Patent Office: 1,134 Days
• Field of Search: 607/86, 607/87, 607/85, 608/02, 608/06, 60/398.3, 608/03, 607/28
• US Class Current: 60/788
• CPC Class Codes: B64D 41/00 Power installations for auxiliary purposes
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02C 3/09 of the centripetal type
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)
• CPC Class Codes: F05D 2240/50 Bearings
• CPC Class Codes: F23R 3/06 Arrangement of apertures along the flame tube
• CPC Class Codes: H02K 7/1823 structurally associated with turbines or similar engines
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An auxiliary power unit (APU) includes a compressor, a turbine, a combustor, and a starter-generator unit all integrated within a single containment housing. The turbine has an output shaft on which the compressor is mounted, and the starter-generator unit is coupled to the turbine output shaft without any intervening gears. The rotating components are all rotationally supported within the containment housing using bearings that do not receive a flow of lubricating fluid.

Claims

1. An auxiliary power unit, comprising:

a combustor;

a turbine having an output shaft, the turbine in fluid communication with at least a portion of the combustor;

a compressor coupled to the turbine output shaft;

a starter-generator unit having at least a rotor mounted on a rotor shaft; and

a quill shaft assembly directly coupled between the turbine output shaft and the starter-generator unit rotor shaft, the quill shaft assembly comprising;

a hollow quill shaft having at least a first end, a second end, an inner surface, and an outer surface, the hollow quill shaft surrounding at least portions of the turbine output shaft and the starter-generator unit rotor shaft,

a first set of splines formed on the quill shaft outer surface at least proximate the quill shaft first end,

a second set of splines formed on the quill shaft outer surface at least proximate the quill shaft second end,

a turbine shaft coupling coupled to, and surrounding a portion of, the turbine output shaft, the turbine shaft coupling including at least a first end, a second end, and an inner surface,

a third set of splines formed on the turbine shaft coupling inner surface and engaging the first set of splines,

a rotor shaft coupling coupled to, and surrounding at least a portion of, the starter-generator unit rotor shaft, the rotor shaft coupling including at least a first end, a second end, and an inner surface, and

a fourth set of splines formed on the rotor shaft coupling inner surface and engaging the second set of splines.

2. The auxiliary power unit of claim 1, wherein the quill shaft assembly is configured to break down upon application thereto of a predetermined torque magnitude.

3. The auxiliary power unit of claim 1, wherein the combustor comprises and annular combustor.

4. The auxiliary power unit of claim 3, wherein the annular combustor is either an inline annular combustor or a radial annular combustor.

5. The auxiliary power unit of claim 1, wherein the combustor comprises a slinger combustor.

6. The auxiliary power unit of claim 1, further comprising:

one or more foil bearings coupled to, and configured to rotationally support, the turbine output shaft.

7. The auxiliary power unit of claim 6, further comprising:

one or more foil bearings coupled to, and configured to rotationally support, at least a portion of the quill shaft assembly.

8. The auxiliary power unit of claim 6, further comprising:

one or more ceramic bearing assemblies coupled to, and configured to rotationally support, at least the starter-generator unit rotor.

9. The auxiliary power unit of claim 6, wherein:

the compressor includes at least an air inlet and a compressed air outlet; and

the one or more foil bearings are in fluid communication with the compressed air outlet.

10. The auxiliary power unit of claim 9, further comprising:

one or more conduits disposed upstream of the compressor air inlet and surrounding at least the turbine output shaft, the one or more conduits having at least an air inlet port and an air outlet port, the air inlet port in fluid communication with the compressed air outlet, and the air outlet port in fluid communication with the one or more foil bearings, whereby air that flows into the compressor air inlet cools air that flows in the one or more conduits and that is supplied to the one or more foil bearings.

11. The auxiliary power unit of claim 1, wherein the starter-generator unit comprises:

a starter-generator housing;

a motor/generator rotationally supported within the starter-generator housing, the motor/generator having at least a rotor that is coupled to the turbine output shaft, the motor/generator configured to selectively operate in either (i) a motor mode, whereby electrical energy is converted to rotational energy and supplied to the turbine output shaft, or (ii) a generator mode, whereby rotational energy is received from the turbine output shaft and converted to electrical energy; and

a control unit mounted within the starter-generator housing, the control unit electrically coupled to the motor/generator and operable to selectively configure the motor/generator to operate in either the motor mode or the generator mode.

12. The auxiliary power unit of claim 1, further comprising:

a containment housing that encloses therein at least the combustor, the turbine, the compressor, the starter-generator unit, and the quill shaft assembly.

13. The auxiliary power unit of claim 12, wherein the containment housing comprises:

an inlet section that encloses at least the starter generator unit and the quill shaft assembly therein; and

an outlet section coupled to the inlet section, the outlet section enclosing at least the combustor, the turbine, and the compressor therein.

14. The auxiliary power unit of claim 13, wherein:

the compressor includes an air inlet and a compressed air outlet;

the containment housing outlet section includes a compressed air plenum and an outlet port, the compressed air plenum in fluid communication with the compressed air outlet, and the outlet port configured to supply compressed air from the compressed air plenum to a bleed air supply system.

15. The auxiliary power unit of claim 1, wherein the turbine is a vaneless turbine.

16. The auxiliary power unit of claim 1, wherein:

the starter-generator unit comprises a motor/generator; and

the motor/generator is configured as a radial gap motor/generator.

17. The auxiliary power unit of claim 1, wherein:

the starter-generator unit comprises a motor/generator; and

the motor/generator is configured as an axial gap motor/generator.

18. An auxiliary power unit, comprising:

a compressor having an air inlet and a compressed air outlet;

a turbine;

one or more foil bearings coupled to, and configured to rotationally support, the turbine, the one or more foil bearings in fluid communication with the compressed air outlet, to thereby receive a flow of cooling air therefrom, and

one or more circumferentially directed heat exchanger conduits disposed upstream of the compressor air inlet and encircling at least the turbine output shaft, the one or more conduits having at least an air inlet port and an air outlet port, the air inlet port in fluid communication with the compressed air outlet, and the air outlet port in fluid communication with the one or more foil bearings, whereby air that flows into the compressor air inlet cools air that flows in the one or more circumferentially directed heat exchanger conduits and that is supplied to the one or more foil bearings.

19. The auxiliary power unit of claim 18, wherein the turbine includes an output shaft, and wherein the auxiliary power unit further comprises:

a starter-generator unit having at least a rotor; and

a quill shaft assembly coupled between the turbine output shaft and the starter-generator unit rotor.

20. The auxiliary power unit of claim 19, further comprising:

one or more foil bearings coupled to, and configured to rotationally support, at least a portion of the quill shaft assembly.

21. The auxiliary power Unit of claim 20, further comprising:

one or more ceramic bearing assemblies coupled to, and configured to rotationally support, at least the starter-generator unit rotor.

22. The auxiliary power unit of claim 19, wherein the quill shaft assembly comprises:

a quill shaft;

a turbine shaft coupling coupled to the turbine output shaft and engaging a first portion of the quill shaft; and

a rotor shaft coupling coupled to the starter-generator unit rotor and engaging a second portion of the quill shaft.

23. The auxiliary power unit of claim 22, further comprising:

a first plurality of splines on an outer surface of the quill shaft;

a second plurality of splines on an inner surface of the turbine shaft coupling, the second plurality of splines engaging at least a portion of the first plurality of splines; and

a third plurality of splines on an inner surface of the rotor shaft coupling, the third plurality of splines engaging at least a portion of the first plurality of splines.

24. The auxiliary power unit of claim 23, wherein the first plurality of splines includes a first portion and a second portion, the first portion disposed proximate a first end of the quill shaft, and the second portion disposed proximate a second end of the quill shaft.

25. The auxiliary power unit of claim 19, wherein the quill shaft assembly is configured to break down upon application thereto of a predetermined torque magnitude.

26. The auxiliary power unit of claim 18, wherein the starter-generator unit comprises:

a starter-generator housing;

a motor/generator rotationally supported within the starter-generator housing, the motor/generator having at least a rotor that is coupled to the turbine output shaft, the motor/generator configured to selectively operate in either (i) a motor mode, whereby electrical energy is converted to rotational energy and supplied to the turbine output shaft, or (ii) a generator mode, whereby rotational energy is received from the turbine output shaft and converted to electrical energy; and

a control unit mounted within the starter-generator housing, the control unit electrically coupled to the motor/generator and operable to selectively configure the motor/generator to operate in either the motor mode or the generator mode.

27. The auxiliary power unit of claim 26, wherein:

the starter-generator unit comprises a motor/generator; and

the motor/generator is configured as a radial gap motor/generator.

28. The auxiliary power unit of claim 26, wherein:

the starter-generator unit comprises a motor/generator; and

the motor/generator is configured as an axial gap motor/generator.

29. The auxiliary power unit of claim 18, further comprising:

a combustor in fluid communication with the turbine and compressed air outlet.

30. The auxiliary power unit of claim 29, wherein the combustor comprises a can-type combustor.

31. The auxiliary power unit of claim 18, further comprising:

a combustor;

a starter-generator unit;

a quill shaft assembly; and

a containment housing that encloses therein at least the combustor, the turbine, the compressor, the starter-generator unit, and the quill shaft assembly.

32. The auxiliary power unit of claim 31, wherein the containment housing comprises:

an inlet section that encloses at least the starter generator unit and the quill shaft assembly therein; and

an outlet section coupled to the inlet section, the outlet section enclosing at least the combustor, the turbine, and the compressor therein.

33. The auxiliary power unit of claim 32, wherein:

the compressor includes an air inlet and a compressed air outlet;

the containment housing outlet section includes a compressed air plenum and an outlet port, the compressed air plenum in fluid communication with the compressed air outlet, and the outlet port configured to supply compressed air from the compressed air plenum to a bleed air supply system.

34. The auxiliary power unit of claim 18, wherein the turbine is a vaneless turbine.

35. An auxiliary power unit, comprising:

a containment housing;

a compressor mounted within the containment housing and including at least an air inlet and a compressed air outlet;

a turbine rotationally supported within the containment housing, the turbine having an output shaft; and

one or more circumferentially directed heat exchanger conduits disposed within the containment housing upstream of the compressor air inlet, at least one of the one or more conduits encircling at least the turbine output shaft and having at least an air inlet port in fluid communication with the compressed air outlet, whereby heat is exchanged between air that flows into the compressor air inlet and air that flows in the one or more circumferentially directed heat exchanger conduits.