Turbofan engine with HP and LP power off-takes

• US 8,966,911 B2
• Filed: 12/06/2010
• Issued: 03/03/2015
• Est. Priority Date: 12/29/2009
• Status: Active Grant

• 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: Ress, Robert A. Jr., Godleski, Todd Anthony
• Primary Examiner(s): Wongwian, Phutthiwat
• Assistant Examiner(s): Amar, Marc J
• Application Number:
  US12/960,779
• Publication Number:
  US 20110154827A1
• Time in Patent Office: 1,548 Days
• Field of Search: 602/68, 60786-788, 607/92, 60/391.62, 60/391.63, 608/01, 608/02
• US Class Current: 60/802
• CPC Class Codes: F02C 7/275 Mechanical drives
• 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: F02K 3/06 with front fan
• CPC Class Codes: F05D 2220/76 an electrical generator
• CPC Class Codes: F05D 2260/4031 as in toothed gearing
• CPC Class Codes: Y10S 74/05 Gas turbine with gearing

Abstract

A turbofan gas turbine engine is provided having a unique power off-take shaft and gear system. Other gas turbine engine types are also contemplated herein. Two power off-takes are provided, one each for the low pressure spool and high pressure spool. The power off-takes extend across a core flow path of the turbofan engine between the low and high pressure shafts to a fan frame of the turbofan. A drive gear is provided near the front end of the high pressure shaft, and another drive gear is provided on the low pressure shaft near the drive gear for the high pressure shaft. Both gears are located in a sump of the gas turbine engine. The power off-take shafts are coupled to the drive gears. Two power devices are coupled to the power off-take shafts and are located in the fan frame. The power devices can be electric generators or motors.

Claims

1. An apparatus comprising:

a gas turbine engine having a first annular flow path disposed radially inward of a second annular flow path and at least two spool shafts;

at least two rotatable shafts extending across the first annular flow path of the gas turbine engine and rotatingly coupled with at least one of the spool shafts;

a first plurality of power devices in power communication with one of the at least two rotatable shafts and disposed between the first annular flow path and the second annular flow path;

wherein the at least two spool shafts includes a first pressure spool shaft and second pressure spool shaft, and wherein one of the at least two rotatable shafts is driven by the first pressure spool shaft, and another of the at least two rotatable shafts is driven by the second pressure spool shaft;

wherein the at least two rotatable shafts are circumferentially offset from each other, and which further includes a second plurality of power devices apart from the first plurality of power devices that are in power communication with another of the at least two rotatable shafts; and

wherein the first plurality of power devices and the second plurality of power devices are disposed within a fan frame of the gas turbine engine.

2. The apparatus of claim 1, which further includes struts to enclose each of the at least two rotatable shafts from at least one of the annular flow paths of the gas turbine engine.

3. The apparatus of claim 1, wherein one of either the first plurality of power devices or the second plurality of power devices are one of a generator or a motor.

4. The apparatus of claim 1, which further includes a sump area of the gas turbine engine, wherein the at least two rotatable shafts couple with the at least two spool shafts in the sump area.

5. The apparatus of claim 1, wherein the at least two rotatable shafts terminate within the fan frame.

6. The apparatus of claim 1, wherein the at least two rotatable shafts are power off-take shafts.

7. An apparatus comprising:

a gas turbine engine having a first shaft of a first spool and a second shaft of a second spool and further having a first flow path radially inward of a second flow path;

a first power shaft oriented to extend across the first flow path of the gas turbine engine and operatively coupled to the first shaft;

a first plurality of power device rotatingly coupled with the first power shaft;

a second power shaft oriented to extend across the first flow path of the gas turbine engine and operatively coupled to the second shaft;

a second plurality of power devices coupled to the second power shaft; and

a fan frame including a plurality of fan frame struts, wherein the first the first and second power shafts are located within the plurality of fan frame struts, and wherein the first plurality of power devices and the second plurality of power devices are located in the fan frame.

8. The apparatus of claim 7, wherein the first shaft is a first pressure spool shaft and the second shaft is a second pressure spool shaft where the first pressure spool shaft is associated with a lower pressure spool than the spool that includes the second pressure spool shaft, and wherein the first power device is located between the first flow path and the second flow path.

9. The apparatus of claim 7, wherein the struts are circumferentially displaced relative to each other, and wherein the second plurality of power devices is coupled to the second power shaft via a multi-pad accessory mount.

10. The apparatus of claim 7, which further includes a bevel gearing arrangement to couple the first and second power shafts to the first and second shafts, respectively.

11. The apparatus of claim 7, wherein the first flow path and second flow path are at least partially defined by the fan frame of the gas turbine engine.

12. A method comprising:

operating a gas turbine engine to compress a working fluid with a compressor and extract a power from a turbine;

flowing the working fluid through a first flow path and a second flow path;

transferring a power via a first power shaft between a first engine spool shaft in rotative communication with the compressor and a first power device of a first plurality of power devices disposed within a fan frame and between the first and second flow paths;

rotating a power shaft, the first power shaft extending across the first flow path and in power communication with the first plurality of power devices;

transferring a power via a second power shaft between a second engine spool shaft in rotative communication with the compressor and another power device of a second plurality of power devices disposed within the fan frame and between the first and second flow paths; and

rotating the second power shaft, the second power shaft extending across the first flow path and in power communication with the second plurality of power devices.

13. The method of claim 12, which further includes delivering power from the first engine spool shaft to the power device.

14. The method of claim 12, wherein the first plurality of power devices is located radially outward of the first flow path.

15. The method of claim 14, wherein the second plurality of power devices is located radially inward of the second flow path.