OFF-SET GEARED TURBOFAN ENGINE

• US 20160363055A1
• Filed: 06/09/2015
• Published: 12/15/2016
• Est. Priority Date: 06/09/2015
• Status: Abandoned Application

• Current Assignee: Rolls-Royce North American Technologies, Inc. (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce North American Technologies, Inc. (Rolls-Royce Holdings Plc)
• Inventors: Edwards, Daniel G.
• Application Number:
  US14/734,066
• Publication Number:
  US 20160363055A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 3/06 with front fan
• CPC Class Codes: F05D 2250/312 the axes being parallel to each other
• CPC Class Codes: F05D 2260/4031 as in toothed gearing

Abstract

A turbofan gas turbine engine includes a first shaft for mounting and rotation of a fan, the first shaft including a single stage internal gear mounted on the first shaft aft of the fan. The turbofan engine further includes a second shaft for mounting and rotation of a low pressure compressor and a low pressure turbine, the second shaft including a pinion gear mounted thereon forward of the low pressure compressor. The pinion gear meshes with the single stage internal gear to drive the first shaft and fan. The second shaft is parallel and off-set from the first shaft.

Claims

1. A turbofan engine comprising:

a fan mounted on a first shaft for rotation of the fan about a first axis of rotation;

at least one internal gear mounted on the first shaft aft of the fan;

a low pressure compressor located aft of the fan;

an engine core located aft of the low pressure compressor;

a low pressure turbine located aft of the engine core;

a second shaft for rotatably supporting the low pressure turbine and low pressure compressor about a second axis of rotation;

at least one second gear affixed to the second shaft forward of the low pressure compressor;

wherein the at least one second gear meshes with the at least one internal gear to drive the first shaft; and

wherein the first axis of rotation is parallel to and radially off-set from the second axis of rotation.

2. The turbofan engine of claim 1 wherein the at least one internal gear is a single stage internal gear.

4. The turbofan engine of claim 1 wherein the fan is a single stage fan.

5. The turbofan engine of claim 1 wherein the engine core comprises a high pressure compressor located aft of the low pressure compressor, a combustor located aft of the high pressure compressor and a high pressure turbine located aft of the combustor.

3. The turbofan engine of claim 3 wherein the at least one second gear is a pinion gear.

6. A turbofan engine comprising:

a fan mounted on a first shaft for rotation of the fan about a first axis of rotation;

a low pressure compressor located aft of the fan;

an engine core located aft of the low pressure compressor;

a low pressure turbine located aft of the engine core;

a second shaft for rotatably supporting the low pressure turbine and low pressure compressor about a second axis of rotation parallel to and radially offset from said first axis;

an offset single stage gear arrangement between said first shaft and said second shaft whereby rotation of said second shaft drives said first shaft.

7. The turbofan engine of claim 6 wherein the single stage gear arrangement includes an internal gear coupled to the first shaft and a pinion gear coupled to the second shaft.

8. The turbofan engine of claim 7 further comprising an air inlet aft of the fan for directing airflow into the low pressure compressor wherein the air inlet is asymmetrical to a centerline of the engine core.

9. The turbofan engine of claim 8 wherein the engine core comprises a high pressure compressor aft of the low pressure compressor, a combustor aft of the high pressure compressor and a high pressure turbine aft of the combustor.

10. A turbofan engine comprising:

a fan section comprising a fan for generating a bypass airflow and an engine core airflow, the fan mounted on a first shaft for rotation of the fan;

at least one internal gear affixed to the first shaft aft of the fan;

an air inlet located aft of the fan for receiving engine core airflow from the fan;

a low pressure compressor located near the air inlet wherein the low pressure compressor receives and compresses engine core airflow from the fan;

an engine core located aft of the low pressure compressor wherein the engine core receives engine core airflow from the low pressure compressor;

a low pressure turbine located aft of the engine core wherein the low pressure turbine receives engine core airflow from the engine core;

a second shaft for mounting and rotating the low pressure turbine and low pressure compressor;

at least one second gear affixed to the second shaft forward of the low pressure compressor;

wherein the at least one second gear meshes with the at least one internal gear to drive the first shaft; and

wherein the relationship between the at least one internal gear and the at least one second gear results in the first shaft being radially offset relative to the second shaft.

11. The turbofan engine of claim 10 wherein the second shaft comprises an axis of rotation about a centerline of the engine core and the air inlet is asymmetrical to said centerline.

12. The turbofan engine of claim 10 wherein the at least one internal gear is a single stage internal gear.

13. The turbofan engine of claim 12 wherein the at least one second gear is a pinion gear.

14. The turbofan engine of claim 10 wherein the fan is a single stage fan.

15. The turbofan engine of claim 10 wherein the engine core comprises a high pressure compressor located aft of the low pressure compressor, a combustor located aft of the high pressure compressor and a high pressure turbine located aft of the combustor.