Gas turbine engine assembly and methods of assembling same

• US 7,493,754 B2
• Filed: 10/19/2005
• Issued: 02/24/2009
• Est. Priority Date: 10/19/2005
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Moniz, Thomas Ory, Orlando, Robert Joseph
• Primary Examiner(s): RODRIGUEZ, WILLIAM H
• Application Number:
  US11/254,018
• Publication Number:
  US 20070084190A1
• Time in Patent Office: 1,224 Days
• Field of Search: 602/28, 602/261, 60/391.62, 415/9, 415/174.4, 416/2
• US Class Current: 60/268
• CPC Class Codes: F01D 25/162 Bearing supports
• CPC Class Codes: F02C 3/107 with two or more rotors connected by power transmission
• 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 3/072 with counter-rotating , e.g. fan rotors
• CPC Class Codes: F05D 2230/642 using maintaining alignment while permitting differential dilatation
• CPC Class Codes: F05D 2250/41 with one degree of freedom
• CPC Class Codes: F05D 2260/40311 of the epicyclical, planetary or differential type
• CPC Class Codes: F16D 1/101 without axial retaining means rotating with the coupling
• CPC Class Codes: F16D 2001/103 the torque is transmitted via splined connections

Abstract

A method for assembling a gas turbine engine including providing a core gas turbine engine at least partially defined by a frame and having a drive shaft rotatable about a longitudinal axis of the core gas turbine engine. A low-pressure turbine is coupled to a core turbine engine. A counter-rotating fan assembly is coupled to the low-pressure turbine. The counter-rotating fan assembly includes a first fan assembly and a second fan assembly. A booster compressor is coupled to the second fan assembly. A gearbox is securely coupled to the frame so that the gearbox is circumferentially positioned about the drive shaft. The first fan assembly is rotatably coupled to an input of the gearbox such that the first fan assembly rotates in a first direction. The second fan assembly is rotatably coupled to an output of the gearbox such that the second fan assembly rotates in a second direction opposite the first direction.

Claims

1. A method for assembling a gas turbine engine, the method comprising:

providing a core gas turbine engine at least partially defined by a frame and having a drive shaft rotatable about a longitudinal axis of the core gas turbine engine;

coupling a low-pressure turbine to a core turbine engine;

coupling a counter-rotating fan assembly including a first fan assembly and a second fan assembly to the low-pressure turbine;

coupling a booster compressor to the second fan assembly;

securely coupling a gearbox to the frame so that the gearbox is circumferentially positioned about the drive shaft;

rotatably coupling the first fan assembly to an input of the gearbox such that the first fan assembly rotates in a first direction by slidably coupling the input to a first portion of a bearing support structure using a first spline assembly and slidably coupling the first portion to a second portion of the bearing support structure using a second spline assembly; and

rotatably coupling the second fan assembly to an output of the gearbox such that the second fan assembly rotates in a second direction opposite the first direction.

2. A method in accordance with claim 1 further comprising isolating the gearbox from axial loads generated by at least one of the first fan assembly, the second fan assembly and the booster compressor.

3. A method in accordance with claim 1 wherein rotatably coupling the second fan assembly to an output of the gearbox further comprises slidably coupling the output to an output structure using a third spline assembly.

4. A method in accordance with claim 1 further comprising rotating the first fan assembly at a first rotational speed and rotating the second fan assembly at a second rotational speed different than the first rotational speed.

5. A method in accordance with claim 1 further comprising rotating the first fan assembly at a first rotational speed and rotating the second fan assembly at a second rotational speed different than the first rotational speed.

6. A method in accordance with claim 1 further comprising rotating the booster compressor at a rotational speed substantially equal to a rotational speed at which the second fan assembly rotates.

7. A spline system for operatively coupling a gearbox to a counter-rotating fan assembly, said spline system comprising:

a first spline assembly coupling an input of said gearbox to a bearing support structure;

a second spline assembly slidably coupling a first portion of said bearing support structure to a second portion of said bearing support structure; and

a third spline assembly slidably coupling an output of said gearbox to an output structure, said spline system isolating said gearbox from axial loads generated by said counter-rotating fan assembly.

8. A spline system in accordance with claim 7 wherein said second spline assembly facilitates axial movement of a first bearing assembly with respect to said gearbox.

9. A spline system in accordance with claim 7 wherein said second spline assembly rotatably couples said input to a drive shaft rotatable about a longitudinal axis of a core gas turbine engine.

10. A spline system in accordance with claim 7 wherein said third spline assembly provides axial movement of an aft fan forward shaft with respect to said gearbox, said aft fan forward shaft coupled to said output structure to facilitate driving an aft fan assembly of said counter-rotating fan assembly.

11. A spline system in accordance with claim 7 wherein at least one of said bearing support structure and said output structure includes at least one flexible arm compensating for a radial deflection of said gearbox

12. A spline system in accordance with claim 7 wherein said counter-rotating fan assembly further comprises:

a first fan assembly rotatably coupled to said input, said first fan assembly rotating in a first direction; and

a second fan assembly rotatably coupled to said output, said second fan assembly rotating in a second direction opposite said first direction.

13. A turbine engine assembly comprising:

a core turbine engine at least partially defined by a frame and having a drive shaft rotatable about a longitudinal axis of said core turbine engine;

a low-pressure turbine coupled to said core turbine engine;

a gearbox securely coupling with respect to said low-pressure turbine;

a first fan assembly coupled to an input of said gearbox, said first fan assembly rotatable in a first rotational direction;

a second fan assembly coupled to an output of said gearbox, said second fan assembly rotatable in a second rotational direction opposite said first direction; and

a spline system isolating said gearbox from axial loads generated by at least one of said first fan assembly and said second fan assembly.

14. A turbine engine assembly in accordance with claim 13 wherein said spline system rotatably couples said input to said drive shaft.

15. A turbine engine assembly in accordance with claim 13 wherein said spline system further comprises:

a first spline assembly slidably coupling said first fan assembly to said input; and

a second spline assembly slidably coupling said second fan assembly to said output.

16. A turbine engine assembly in accordance with claim 15 wherein said spline system further comprises a third spline assembly slidably coupling a first portion of a bearing support structure to a second portion of said bearing support structure.

17. A turbine engine assembly in accordance with claim 16 wherein said third spline assembly couples said input to a first bearing assembly mounted to said bearing support structure.

18. A turbine engine assembly in accordance with claim 16 wherein said third spline assembly facilitates axial movement of a first bearing assembly with respect to said gearbox.

19. A turbine engine assembly in accordance with claim 15 wherein said second spline assembly facilitates axial movement of said second fan assembly with respect to said gearbox.