GRAVITY SCAVENGED GENERATOR WITH INTEGRAL ENGINE OIL TANK

• US 20100019505A1
• Filed: 07/24/2008
• Published: 01/28/2010
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Frost, Cristopher
• Granted Patent: US 8,893,856 B2
• Time in Patent Office: Days
• US Class Current: 290/1.A
• CPC Class Codes: B64D 2041/002 Mounting arrangements for auxiliary power units (APU's)
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F05D 2260/602 Drainage
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A generator having an integral oil tank for an auxiliary power unit (APU) is provided. A gas turbine engine has a turbine shaft extending from an aft portion to a forward portion where it is in communication with a gear box mounted thereto. The gearbox advantageously has at least one oil gravity drain passage in flow communication with a lower portion thereof and is suitable for reducing the speed of the turbine shaft by gear reduction to power an oil cooled generator attached thereto. The oil cooled generator has at least one oil gravity drain passage therein. An engine oil tank is integral with and advantageously removable from the generator and is in flow communication with each oil gravity drain passage making is suitable for gravity scavenging oil from the generator and advantageously the gearbox.

Claims

1. An auxiliary power unit for an aircraft comprising:

an oil cooled generator mounted proximate an end of said auxiliary power unit receiving power from a power section of said auxiliary power unit, said oil cooled generator having at least one oil gravity drain passage in flow communication with a lower portion thereof; and

an engine oil tank having a sidewall, a bottom wall, and an open top, a portion of said sidewall being mounted to said generator, said bottom wall being positioned below said lower portion of said oil cooled generator, said oil tank gravitationally scavenging oil from said at least one oil gravity drain passage in said oil cooled generator.

2. The auxiliary power unit of claim 1 wherein said oil tank is positioned substantially under said lower portion of said generator.

3. The auxiliary power unit of claim 1 wherein said oil tank has an attachment flange extending outward from said sidewall.

4. The auxiliary power unit of claim 1 wherein said lower portion of said generator has an open bell shape, a lower exterior perimeter of said open bell shaped lower portion has a flange outwardly extending therefrom.

5. The auxiliary power unit of claim 1 wherein said generator has an oil gravity drain passage in flow communication with each end of a generator rotor.

6. The auxiliary power unit of claim 1 having a screen between said at least one oil gravity drain passage and said bottom wall of said oil tank.

7. The auxiliary power unit of claim 1 wherein said oil tank is removably mounted to said generator.

8. The auxiliary power unit of claim 1 wherein said oil tank is comprised of fire resistant material.

9. The auxiliary power unit of claim 8 wherein said oil tank is comprised of steel.

10. The auxiliary power unit of claim 1 wherein said oil tank sidewall is cylindrical.

11. The auxiliary power unit of claim 1 wherein said oil tank bottom wall slopes toward a lower portion.

12. The auxiliary power unit of claim 11 wherein said oil tank bottom wall is conical.

13. The auxiliary power unit of claim 1 being installed in the tailcone of an aircraft in a horizontal or forward end angled down orientation, said auxiliary power unit forward end having said generator.

14. An auxiliary power unit comprising:

an oil cooled generator and oil tank assembly, said oil tank extending from a lower portion of said generator, said generator receiving power from a power section of said auxiliary power unit at a reduced rotational speed and having an oil gravity drain passage in flow communication with each end of a generator rotor, said oil gravity drain passages being in flow communication with said oil tank.

15. The auxiliary power unit of claim 14 wherein said auxiliary power unit has an oil gravity drain passage in flow communication with a gearbox and a power section forward bearing housing, each of said oil gravity drain passages being in flow communication with said oil tank.

16. The auxiliary power unit of claim 14 wherein said oil tank is removable from said generator.

17. The auxiliary power unit of claim 14 wherein said generator and oil tank assembly has a screen therein above a bottom wall of said oil tank and below said oil gravity drain passages in said generator.

18. The auxiliary power unit of claim 14 wherein said oil tank has a sidewall extending downward from said generator to a bottom wall, said bottom wall sloping to a lower portion having an oil tank drain plug.

19. A generator with an oil tank suitable for use with an auxiliary power unit for an aircraft comprising:

a rotor with an oil gravity drain passage in flow communication with at least one end thereof and a lower portion of said generator; and

an oil tank removably mounted to said generator having an open top in flow communication with said oil gravity drain passages gravity scavenging oil from said generator during operation thereof.

20. The generator of claim 19 wherein said oil tank is in flow communication with at least one oil gravity drain passage in a gearbox of said auxiliary power unit.