TURBINE ENGINE GEARBOX

• US 20140155219A1
• Filed: 02/07/2014
• Published: 06/05/2014
• Est. Priority Date: 01/31/2012
• Status: Active Grant

• Current Assignee: Ohio State University, Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: McCune, Michael E., Kahraman, Ahmet
• Granted Patent: US 9,169,781 B2
• Time in Patent Office: Days
• US Class Current: 475/331
• CPC Class Codes: F01D 15/12 Combinations with mechanical gearing driven by multiple engines F01D13/00
• 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: F02K 3/04 the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type
• CPC Class Codes: F02K 3/072 with counter-rotating , e.g. fan rotors
• CPC Class Codes: F05D 2260/40311 of the epicyclical, planetary or differential type
• CPC Class Codes: F16H 1/28 with gears having orbital motion
• CPC Class Codes: F16H 1/46 Systems consisting of a plurality of gear trains each with orbital gears, i.e. systems having three or more central gears
• CPC Class Codes: F16H 57/0006 Vibration-damping or noise reducing means specially adapted for gearings devices for varying tension of belts, ropes or chains with damping means F16H7/0829; toothed members with construction providing vibration damping F16H55/14; reducing vibrations or noise of the gearbox casing F16H57/028; suppression of vibrations or noise of gear selectors F16H59/0208; control of hydrostatic fluid gearing preventing or reducing vibrations or noise F16H61/4183
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A gas turbine engine comprises a fan, and a fan drive turbine rotor. The fan drive turbine drives the fan through a gear reduction. The gear reduction includes at least two double helical gears in meshed engagement. Each of the at least two double helical gears are disposed to rotate about respective axes, and each have a first plurality of gear teeth axially spaced from a second plurality of gear teeth by a spacer. Each of the first plurality of gear teeth has a first end facing the spacer and each of the second plurality of gear teeth has a first end facing the spacer. Each first end of the first plurality of gear teeth is circumferentially offset from each first end of the second plurality of gear teeth.

Claims

1. A gas turbine engine comprising:

a fan;

a fan drive turbine rotor to drive the fan through a gear reduction; and

the gear reduction including at least two double helical gears in meshed engagement, each of the at least two double helical gears disposed to rotate about respective axes, and each of the at least two double helical gears having a first plurality of gear teeth axially spaced from a second plurality of gear teeth by a spacer, wherein each of the first plurality of gear teeth has a first end facing the spacer and each of the second plurality of gear teeth has a first end facing the spacer, with each first end of the first plurality of gear teeth being circumferentially offset from each first end of the second plurality of gear teeth.

2. The gas turbine engine as set forth in claim 1, wherein the fan drive turbine for driving a compressor rotor, along with the fan through the gear reduction.

3. The gas turbine engine as set forth in claim 2, wherein the first plurality of gear teeth are offset from the second plurality of gear teeth by a circumferential offset distance of about 25% to about 75% of the circumferential offset.

4. The gas turbine engine as set forth in claim 3, wherein the gear reduction includes an epicyclic gear system.

5. The gas turbine engine as set forth in claim 4, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

6. The gas turbine engine as set forth in claim 2, wherein the gearbox includes an epicyclic gear system.

7. The gas turbine engine as set forth in claim 6, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

8. The gas turbine engine as set forth in claim 2, wherein a gear ratio of the gear reduction being greater than or equal to about 2.5:

1.

9. The gas turbine engine as set forth in claim 1, wherein there are two additional turbine rotors, with one of the two additional turbine rotors driving a low pressure compressor rotor, and a second of the additional turbine rotors driving a high pressure compressor rotor.

10. The gas turbine engine as set forth in claim 9, wherein a gear ratio of the gear reduction being greater than or equal to about 2.3:

1.

11. The gas turbine engine as set forth in claim 9, wherein the gear reduction includes an epicyclic gear system.

12. The gas turbine engine as set forth in claim 11, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

13. The gas turbine engine as set forth in claim 1, wherein the gear reduction includes an epicyclic gear system.

14. The gas turbine engine as set forth in claim 13, wherein the first plurality of gear teeth and the second plurality of gear teeth about each double helical gear are disposed at a helix angle relative to an axis.

15. The gas turbine engine as set forth in claim 14, wherein the helix angle is between about 30-35°

.

16. The gas turbine engine as set forth in claim 13, wherein a gear ratio of the gear reduction being greater than or equal to about 2.3:

1.

17. The gas turbine engine as set forth in claim 1, wherein the fan drive turbine further driving a compressor rotor, with the compressor rotor also being driven through the gear reduction by the fan drive turbine rotor.

18. The gas turbine engine as set forth in claim 17, wherein the gear reduction includes an epicyclic gear system.

19. The gas turbine engine as set forth in claim 18, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

20. The gas turbine engine as set forth in claim 1, wherein a gear ratio of the gear reduction being greater than or equal to about 2.3:

1.

21. A method of designing a gas turbine engine comprising:

providing a fan;

providing a fan drive turbine rotor to drive the fan through a gear reduction; and

the gear reduction including at least two double helical gears in meshed engagement, each of the at least two double helical gears disposed to rotate about respective axes, and each of the at least two double helical gears having a first plurality of gear teeth axially spaced from a second plurality of gear teeth by a spacer, wherein each of the first plurality of gear teeth has a first end facing the spacer and each of the second plurality of gear teeth has a first end facing the spacer, with each first end of the first plurality of gear teeth being circumferentially offset from each first end of the second plurality of gear teeth.

22. The method as set forth in claim 21, wherein the fan drive turbine for driving a compressor rotor, along with the fan through the gear reduction.

23. The method as set forth in claim 22, wherein the first plurality of gear teeth are offset from the second plurality of gear teeth by a circumferential offset distance of about 25% to about 75% of the circumferential offset.

24. The method as set forth in claim 23, wherein the gear reduction includes an epicyclic gear system.

25. The method as set forth in claim 24, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

26. The method as set forth in claim 22, wherein the gearbox includes an epicyclic gear system.

27. The method as set forth in claim 26, wherein the gear reduction is an epicyclic gear system that includes a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and ring gear.

28. The method as set forth in claim 22, wherein a gear ratio of the gear reduction being greater than or equal to about 2.5:

1.

29. The method as set forth in claim 21, wherein there are two additional turbine rotors, with one of the two additional turbine rotors driving a low pressure compressor rotor, and a second of the additional turbine rotors driving a high pressure compressor rotor.

30. The method as set forth in claim 29, wherein a gear ratio of the gear reduction being greater than or equal to about 2.3:

1.