SPLIT ACCESSORY DRIVE SYSTEM

• US 20130098058A1
• Filed: 10/19/2011
• Published: 04/25/2013
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Sheridan, William G.
• Granted Patent: US 9,062,611 B2
• Time in Patent Office: Days
• US Class Current: 60/783
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F01D 25/20 using lubrication pumps
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F05D 2260/4031 as in toothed gearing
• CPC Class Codes: F05D 2260/98 Lubrication

Abstract

A gas turbine engine includes a spool, a first accessory gearbox, a second accessory gearbox, and a scavenge pump. The first accessory gearbox is connected to and driven by the spool. The second accessory gearbox is connected to and driven by the first accessory gearbox. The scavenge pump is connected between the first accessory gearbox and the second accessory gearbox. The first accessory gearbox drives the second accessory gearbox through the scavenge pump.

Claims

1. A gas turbine engine comprising:

a spool;

a first accessory gearbox connected to and driven by the spool;

a second accessory gearbox connected to and driven by the first accessory gearbox; and

a scavenge pump connected between the first accessory gearbox and the second accessory gearbox, wherein the first accessory gearbox drives the second accessory gearbox through the scavenge pump.

2. The gas turbine engine of claim 1, wherein the first accessory gearbox is positioned substantially inside a core cowling and wherein the second accessory gearbox is positioned substantially outside of the core cowling.

3. The gas turbine engine of claim 2, wherein the second accessory gearbox is positioned on a fan case.

4. The gas turbine engine of claim 3, and further comprising:

a supply pump connected to and driven by the second accessory gearbox;

an oil tank positioned on the fan case;

an oil filter positioned on the fan case; and

a lubrication circuit connecting the scavenge pump, the supply pump, the oil tank, and the oil filter.

5. The gas turbine engine of claim 3, wherein the second accessory gearbox is positioned within a nacelle on the fan case.

6. The gas turbine engine of claim 2, and further comprising:

a generator connected to and driven by the first accessory gearbox;

a fuel pump connected to and driven by the first accessory gearbox;

a hydraulic pump connected to and driven by the first accessory gearbox; and

a starter connected to and driven by the first accessory gearbox.

7. The gas turbine engine of claim 6, and further comprising:

a permanent magnet generator connected to and driven by the second accessory gearbox; and

an electronic engine controller powered by the permanent magnet generator and positioned on the fan case.

8. The gas turbine engine of claim 1, wherein the scavenge pump is mounted to the first accessory gearbox.

9. The gas turbine engine of claim 1, and further comprising:

a first gear system connecting the spool to the first accessory gearbox; and

a second gear system connecting the scavenge pump to the second accessory gearbox.

10. The gas turbine engine of claim 9, wherein the second gear system comprises:

a first bevel gear connected to a shaft of the scavenge pump;

a tower shaft having second and third bevel gears, wherein the second bevel gear is connected to the first bevel gear; and

a lay shaft having a fourth bevel gear connected to the third bevel gear, wherein the lay shaft is connected to and drives the second accessory gearbox.

11. The gas turbine engine of claim 1, wherein the gas turbine engine is a turbofan engine, and further comprising:

a fan bypass positioned between the first accessory gearbox and the second accessory gearbox.

12. The gas turbine engine of claim 1, wherein the second accessory gearbox is smaller than the first accessory gearbox.

13. A method for driving accessories on a gas turbine engine, the method comprising:

driving a scavenge pump via a first accessory gearbox;

driving a second accessory gearbox via the scavenge pump; and

driving a supply pump via the second accessory gearbox.

14. The method of claim 13, wherein the first accessory gearbox is connected to and driven by a spool of the gas turbine engine via a first gear system and wherein the second accessory gearbox is connected to and driven by the scavenge pump via a second gear system.

15. The method of claim 13, wherein the second accessory gearbox fails to drive the supply pump in response to a failure of the scavenge pump.

16. The method of claim 13, and further comprising:

pumping lubricating liquid to a plurality of gas turbine engine components via the supply pump; and

scavenging lubricating liquid from the plurality of gas turbine engine components via the scavenge pump.

17. The method of claim 13, and further comprising:

driving a generator, a fuel pump, a hydraulic pump, and a starter via the first accessory gearbox; and

driving a permanent magnet generator via the second accessory gearbox.

18. The method of claim 13, wherein the scavenge pump is mounted to the first accessory gearbox.

19. The method of claim 13, and further comprising:

venting air from the first accessory gearbox to the second accessory gearbox.

20. The method of claim 19, and further comprising:

venting air from the second accessory gearbox through a deoiler positioned on the second accessory gearbox.