Gas turbine engine with intermediate speed booster

• US 8,209,952 B2
• Filed: 10/09/2007
• Issued: 07/03/2012
• Est. Priority Date: 08/22/2006
• 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.
• Primary Examiner(s): Casaregola, Louis
• Application Number:
  US11/973,451
• Publication Number:
  US 20090293445A1
• Time in Patent Office: 1,729 Days
• Field of Search: 60/391.63, 602/261, 607/74, 607/91, 607/92
• US Class Current: 60/226.1
• CPC Class Codes: F02C 3/067 having counter-rotating rotors F02C3/073 takes precedence
• 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 3/04 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 3/06 with front fan
• CPC Class Codes: F02K 3/072 with counter-rotating , e.g. fan rotors
• CPC Class Codes: F05D 2220/326 to drive shrouded, low solidity propeller
• CPC Class Codes: F05D 2220/327 to drive shrouded, high solidity propeller
• CPC Class Codes: F05D 2260/4023 through a friction clutch
• CPC Class Codes: F05D 2260/40311 of the epicyclical, planetary or differential type

Abstract

A gas turbine engine having speed an intermediate stage booster configured to provide speed change to a boost compressor. The boost compressor and fan stage are driven by a low pressure turbine; the fan stage rotates with the low pressure turbine shaft and the boost compressor rotates counter to the low pressure turbine shaft. The intermediate speed booster has an epicyclic gear train that includes an outer annulus, a sun gear, and a planetary gear, and may be engaged by a clutch in some embodiments.

Claims

1. A turbofan engine comprising:

turbomachinery components limited to two shaft driven spools, the components including a low pressure spool and a high pressure spool, the low pressure spool including a low pressure turbine;

a low pressure shaft coupled to and rotatable by operation of said low pressure turbine;

a bladed air moving device coupled to said low pressure shaft;

a boost compressor located downstream of said bladed air moving device and substantially free from driven rotation with respect to the high pressure spool; and

a mechanical speed booster coupled with said low pressure shaft and said boost compressor, said mechanical speed booster operable to drive said boost compressor at a rotational speed different than the rotational speed of said low pressure shaft.

2. The turbofan engine of claim 1, wherein the mechanical speed booster is operable to drive said boost compressor at a rotational speed greater than the rotational speed of said shaft.

3. The turbofan engine of claim 1, wherein said mechanical speed booster includes a gear train.

4. The turbofan engine of claim 3, wherein the gear train is an epicyclic gear train having a sun gear, an annulus gear, and a plurality of planet gears.

5. The turbofan engine of claim 1, wherein the mechanical speed booster is operable to drive said boost compressor at a rotational speed within a range from 1.5 to 3 times the rotational speed of said shaft.

6. The turbofan engine of claim 1, which further includes a clutch operable to selectively engage and disengage said mechanical speed booster with said shaft.

7. The turbofan engine of claim 1, which further includes a radial intershaft bearing to support said boost compressor.

8. The turbofan engine of claim 1, which further includes means for carrying the load associated with said bladed air moving device.

9. The turbofan of claim 1, wherein said bladed air moving device rotates at the rotational speed of said shaft, and wherein said bladed air moving device is a fan.

10. The turbofan engine of claim 1, wherein the mechanical speed booster is operable to drive said boost compressor at a rotational speed less than the rotational speed of said shaft.

11. The turbofan engine of claim 1, wherein said mechanical speed booster includes a gear train, said gear train is an epicyclic gear train having a sun gear, an annulus gear, and a plurality of planet gears;

which further includes means for carrying the load associated with said bladed air moving device; and

wherein said bladed air moving device rotates at the rotational speed of said shaft.

12. The turbofan engine of claim 1, wherein said boost compressor includes a plurality of stages.

13. The turbofan engine of claim 1, wherein said bladed air moving device and boost compressor rotate in opposite directions.

14. A gas turbine engine comprising:

a dual spool turbine having a low pressure turbine and a high pressure turbine;

a high pressure compressor;

a shaft coupled to and rotatable by operation of said low pressure turbine;

a boost compressor located upstream of said high pressure compressor and incapable of mechanical connection with respect to rotation of the high pressure compressor; and

a transmission coupled with said low pressure shaft and said boost compressor, said transmission operable to drive said boost compressor at a rotational speed different than the rotational speed of said low pressure shaft;

wherein the gear train is an epicyclic gear train having a sun gear, an annulus gear, and a plurality of planet gears.

15. The gas turbine engine of claim 14, wherein said transmission is operable to drive said boost compressor at a rotational speed greater than the rotational speed of said low pressure shaft.

16. The gas turbine engine of claim 14, which further includes means for selectively engaging and disengaging the transmission of power from said low pressure shaft to said transmission.

17. The gas turbine engine of claim 14, wherein said transmission operable to drive said boost compressor at a rotational speed less than the rotational speed of said low pressure shaft.

18. The gas turbine engine of claim 14, wherein the gas turbine engine is a turboprop.

19. The gas turbine engine of claim 14, wherein the gas turbine engine is a turboshaft.

20. A turbofan engine comprising:

a relatively low pressure turbine;

a shaft coupled to and rotatable by operation of said relatively low pressure turbine;

a bladed rotor coupled to said shaft;

a boost compressor located downstream of said bladed rotor;

means for rotational speed change of said boost compressor stage; and

means for selective coupling of the boost compressor to the shaft.

21. A turbofan engine comprising:

a turbine;

a shaft coupled to and rotatable by operation of said turbine;

a fan coupled to said shaft and fixed to the rotational speed of said shaft;

a boost compressor coupled to said shaft;

a gear box between said shaft and said boost compressor, said gear box operable to drive said boost compressor at a rotational speed different than the rotational speed of said shaft; and

a clutch operable to selectively engage and disengage the transmission of power from said shaft to said boost compressor.

22. The turbofan engine of claim 21, wherein said gear box is operable to drive said boost compressor at a rotational speed greater than the rotational speed of said shaft.

23. The turbofan engine of claim 21, which further includes means for carrying the load associated with said fan.

24. The turbofan of claim 21, wherein said fan rotates in the same direction as said shaft and wherein said boost compressor rotates in the opposite direction of said fan.