MULTI-SPOOL GAS TURBINE ENGINE ARCHITECTURE

• US 20180023481A1
• Filed: 12/20/2016
• Published: 01/25/2018
• Est. Priority Date: 07/19/2016
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: LEFEBVRE, Guy
• Granted Patent: US 10,883,424 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 27/10 of gas-turbine type jet aircraft B64D27/16
• CPC Class Codes: B64D 35/04 characterised by the transmission driving a plurality of propellers or rotors
• CPC Class Codes: F01D 15/12 Combinations with mechanical gearing driven by multiple engines F01D13/00
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F01D 5/026 Shaft to shaft connections
• CPC Class Codes: F02C 3/08 the compressor comprising at least one radial stage F02C3/10 takes precedence
• CPC Class Codes: F02C 3/10 with another turbine driving an output shaft but not driving the compressor
• CPC Class Codes: F02C 3/107 with two or more rotors connected by power transmission
• CPC Class Codes: F02C 3/113 with variable power transmission between rotors
• CPC Class Codes: F02C 3/145 the combustion chamber being in the reverse flow-type
• CPC Class Codes: F02C 6/206 the vehicles being airscrew driven
• CPC Class Codes: F02C 7/06 Arrangements of bearings bearings F16C; Lubricating of turbo machines F01D25/18; of machines or engines in general F01M
• 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 2220/32 in gas turbines
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2220/324 to drive unshrouded, low solidity propeller
• CPC Class Codes: F05D 2220/329 in helicopters
• CPC Class Codes: F05D 2230/70 Disassembly methods
• CPC Class Codes: F05D 2230/72 : Maintenance
• CPC Class Codes: F05D 2240/61 : Hollow
• CPC Class Codes: F05D 2250/36 : in inner-outer relationship, e.g. shaft-bearing arrangements
• CPC Class Codes: F05D 2260/31 : Retaining bolts or nuts
• CPC Class Codes: F05D 2260/36 : by a form fit connection, e.g. by interlocking
• CPC Class Codes: F05D 2260/40 : Transmission of power
• CPC Class Codes: F05D 2260/4031 : as in toothed gearing
• CPC Class Codes: F05D 2260/40311 : of the epicyclical, planetary or differential type
• CPC Class Codes: F05D 2260/98 : Lubrication
• CPC Class Codes: F16H 57/0495 : with fixed gear ratio
• CPC Class Codes: Y02T 50/40 : Weight reduction
• CPC Class Codes: Y02T 50/60 : Efficient propulsion technologies, e.g. for aircraft

Abstract

A multi-spool gas turbine engine comprises a low pressure (LP) spool and a high pressure (HP) spool independently rotatable about a central axis. The LP pressure spool has an LP compressor and an LP turbine. The HP spool has an HP turbine and an HP compressor. An accessory gear box (AGB) is drivingly connected to the HP spool. The LP compressor is disposed axially between the HP compressor and the AGB. A gear train drivingly couples the LP compressor to the LP turbine. The gear train is integrated to the AGB.

Claims

1. A reverse flow gas turbine engine comprising:

a low pressure (LP) spool and a high pressure (HP) spool rotatable independently of one another about an engine axis;

the LP spool comprising an LP turbine, an LP compressor and an LP shaft drivingly connected to the LP turbine, the LP turbine disposed forward of the LP compressor relative to a direction of travel of the engine;

the HP spool comprising an HP turbine, an HP compressor and an HP shaft drivingly connecting the HP turbine to the HP compressor, the HP compressor disposed forward of the LP compressor and in fluid communication therewith, the HP turbine disposed aft of the LP turbine and in fluid communication therewith;

an accessory gear box (AGB) drivingly connected to the HP spool, the LP compressor disposed axially between the HP compressor and the AGB, and

a gear train drivingly coupling the LP shaft to the LP compressor, the gear train disposed aft of the LP compressor.

2. The reverse flow gas turbine engine defined in claim 1, wherein the gear train coupling the LP shaft to the LP compressor and the AGB share a common housing.

3. The reserve flow gas turbine engine defined in claim 1, wherein the LP shaft extends axially through a central bore of the LP compressor and projects axially aft of the LP compressor.

4. The reverse flow gas turbine engine defined in claim 3, wherein the LP shaft extends into the AGB.

5. The reserve flow gas turbine engine defined in claim 3, wherein the gear train is disposed in the AGB and is drivingly coupled to an aft end of the LP shaft.

6. The reverse flow gas turbine engine defined in claim 1, wherein the gear train is a dual gear train comprising first and second drive inputs to the LP compressor.

7. The reverse flow gas turbine engine defined in claim 5, wherein the gear train comprises first and second sets of gears, the LP shaft being drivingly coupled to both said first and second sets of gears for driving the LP compressor.

8. The reverse flow gas turbine engine defined in claim 1, wherein the LP shaft is a one piece shaft having a power turbine shaft portion extending forwardly of the LP turbine and a LP compressor shaft portion extending rearwardly from the LP turbine to a location aft of the LP compressor.

9. The reverse flow gas turbine engine defined in claim 8, wherein the LP shaft extends centrally through the HP shaft, and wherein the LP shaft is supported by at least one bearing mounted in an internal cavity disposed between the HP compressor and the LP compressor and radially inwardly of an annular gas path between the HP compressor and LP compressor.

10. The reverse flow gas turbine engine defined in claim 9, wherein the HP shaft comprises a first shaft section projecting aft of the HP compressor and a second shaft section projecting axially through the LP compressor into the AGB, and wherein a gear is disposed in the internal cavity to drivingly connect the first shaft section to the second shaft section.

11. The reverse flow gas turbine engine defined in claim 10, wherein the gear is a bevel gear having a rotation axis perpendicular to the engine axis.

12. The reverse flow gas turbine engine defined in claim 1, comprising a split casing including first and second separable casing sections having an interface between the HP compressor and the LP compressor to provide access to an internal cavity disposed radially inwardly of an annular gaspath between the LP and HP compressors, the internal cavity housing at least one bearing supporting the LP shaft.

13. The reverse flow gas turbine engine defined in claim 12, wherein the HP shaft has a first shaft section projecting aft of the HP compressor and a second shaft section projecting axially through the LP compressor into the AGB, and wherein the first and second shaft sections are drivingly connected by a bevel gear housed in the internal cavity, the at least one bearing being disposed between said first and second shaft sections of the HP shaft.

14. The reverse flow gas turbine engine defined in claim 1, wherein the AGB has an input axis coaxial to the engine axis.

15. The reverse flow gas turbine engine defined in claim 14, wherein the HP shaft extends axially through a central bore of the LP compressor and project axially aft of the LP compressor in driving engagement with the AGB.

16. A multi-spool gas turbine engine comprising:

a low pressure (LP) spool;

a high pressure (HP) spool, the LP spool and the HP spool rotatable independently of one another about a central axis, the LP pressure spool comprising an LP compressor and an LP turbine, the HP spool comprising an HP turbine and an HP compressor;

an accessory gear box (AGB) drivingly connected to the HP spool, the LP compressor disposed axially between the HP compressor and the AGB, and a gear train drivingly coupling the LP compressor to the LP turbine, the gear train disposed on an AGB facing side of the LP compressor.

17. The multi-spool gas turbine engine defined in claim 16, wherein the LP spool comprises an LP shaft extending axially from the LP turbine through a central bore of the LP compressor and in driving engagement with the gear train.

18. The multi-spool gas turbine engine defined in claim 17, wherein the LP compressor has a hollow compressor shaft portion extending concentrically about the LP shaft on the AGB facing side of the LP compressor, the hollow compressor shaft portion being drivingly connected to the LP shaft by the gear train.

19. The multi-spool gas turbine engine defined in claim 18, wherein the HP spool comprises a HP shaft drivingly connected to the HP turbine and extending axially though the central bore of the LP compressor between the LP shaft and the hollow compressor shaft portion of the LP compressor, the HP shaft being drivingly connected to the AGB.

20. The multi-spool gas turbine engine defined in claim 19, wherein the LP shaft extends into the AGB axially beyond the HP shaft and the hollow compressor shaft portion of the LP compressor.

21. The multi-spool gas turbine engine defined in claim 20, wherein the HP shaft ends axially between the hollow compressor shaft portion of the LP compressor and the LP shaft.

22. The multi-spool gas turbine engine defined in claim 19, wherein the HP shaft comprises first and second shaft sections drivingly coupled by a bevel gear disposed in a cavity between the HP compressor and the LP compressor radially inwardly of a gas path between the HP and LP compressors.

23. The multi-spool gas turbine engine defined in claim 22, wherein at least one bearing is provided in the cavity between the first and second shaft sections of the HP shaft, the at least one bearing supporting the LP shaft.

24. The multi-spool gas turbine engine defined in claim 17, wherein the gear train is a dual gear train comprising first and second sets of gears respectively disposed on opposed lateral sides of the LP shaft to provide first and second drive inputs to the LP compressor.

25. The multi-spool gas turbine engine defined in claim 22, wherein the cavity is defined by first and second casing sections having a mounting interface disposed between the HP compressor and the LP compressor, the first and second casing sections being separable to provide access to said cavity.

26. The multi-spool gas turbine engine defined in claim 16, wherein the engine is an aircraft engine having a reverse flow configuration including an air inlet disposed aft of the LP compressor along a direction of travel of the aircraft engine, and wherein the AGB is disposed aft of the air inlet.