START SYSTEM FOR GAS TURBINE ENGINES

• US 20130183136A1
• Filed: 01/17/2012
• Published: 07/18/2013
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Roberge, Gary D., Berryann, Andrew P., Carr, Scott A.
• Granted Patent: US 10,125,724 B2
• Time in Patent Office: Days
• US Class Current: 415/1
• CPC Class Codes: F01D 1/023 the working-fluid being divided into several separate flows F01D3/02 takes precedence; several separate fluid flows being united in a single flow; the machine or engine having provision for two or more different possible fluid flow paths
• CPC Class Codes: F01D 17/00 Regulating or controlling by varying flow for reversing F01D1/30; by varying rotor-blade position F01D7/00; specially for starting F01D19/00; shutting-down F01D21/00; regulating or controlling in general G05 ; specially adapted for hand-held tools or the like F01D15/06
• CPC Class Codes: F01D 19/00 Starting of machines or engines; Regulating, controlling, or safety means in connection therewith warming-up before starting F01D25/10; turning or inching gear F01D25/34
• CPC Class Codes: F01D 9/04 forming ring or sector
• CPC Class Codes: F01D 9/065 Fluid supply or removal conduits traversing the working fluid flow, e.g. for lubrication-, cooling-, or sealing fluids see also F01D25/16, F01D25/24 and F01D25/26
• CPC Class Codes: F02K 3/075 controlling flow ratio between flows
• CPC Class Codes: F04D 27/002 by varying geometry within the pumps, e.g. by adjusting vanes
• CPC Class Codes: F04D 27/009 by bleeding, by passing or recycling fluid
• CPC Class Codes: F04D 29/524 shiftable members for obturating part of the flow path
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2240/12 Fluid guiding means, e.g. vanes
• CPC Class Codes: F05D 2250/35 rotated
• CPC Class Codes: F05D 2250/411 in rotation
• CPC Class Codes: F05D 2250/90 Variable geometry
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A gas turbine engine includes a flow control mechanism operable to direct at least a portion of a fan airflow from a secondary flow path into a core flow path.

Claims

1. A gas turbine engine comprising:

a high spool along an engine axis, said high spool operable to communicate a core airflow through a core flow path;

a fan section operable to communicate a fan airflow into a secondary flow path and said core flow path;

a low spool along said engine axis to drive said fan section; and

a flow control mechanism operable to direct at least a portion of said fan airflow from said secondary flow path into said core flow path.

2. The gas turbine engine as recited in claim 1, wherein said flow control mechanism is movable between an open position and a closed position.

3. The gas turbine engine as recited in claim 1, wherein said flow control mechanism is a fan duct blocker ring.

4. The gas turbine engine as recited in claim 1, wherein said flow control mechanism is a nozzle.

5. The gas turbine engine as recited in claim 1, further comprising a starter/generator connected to said low spool.

6. The gas turbine engine as recited in claim 5, wherein said starter/generator is forward of said low spool.

7. The gas turbine engine as recited in claim 5, wherein said starter/generator is aft of said low spool.

8. The gas turbine engine as recited in claim 5, wherein said starter/generator is driven by said low spool through a towershaft.

9. The gas turbine engine as recited in claim 1, wherein said high spool along said engine axis with a high pressure compressor section and a high pressure turbine section, said high pressure compressor section includes a variable guide vane.

10. The gas turbine engine as recited in claim 1, wherein said high spool along said engine axis with a high pressure compressor section and a high pressure turbine section, said high pressure turbine section includes a variable guide vane.

11. The gas turbine engine as recited in claim 1, wherein said fan section includes a variable pitch fan blade.

12. The gas turbine engine as recited in claim 1, wherein said fan section includes a variable pitch vane.

13. The gas turbine engine as recited in claim 1, wherein said high spool along said engine axis with a high pressure compressor section and a high pressure turbine section, a start bleed in selective communication with said high pressure compressor section.

14. The gas turbine engine as recited in claim 1, wherein said low spool drives said fan section through a geared architecture.

15. A method of operating a gas turbine engine comprising:

driving a low spool to generate a fan airflow from a fan section connected to the low spool; and

modulating a flow control mechanism to direct at least a portion of the fan airflow from a secondary flow path into a core flow path to drive a high spool.

16. The method as recited in claim 15, wherein no accessory gearbox is driven by the high spool.

17. The method as recited in claim 15, further comprising:

rotating the high spool in a direction opposite that of the low spool.

18. The method as recited in claim 15, further comprising:

driving the fan section through a geared architecture driven by the low spool.

19. The method as recited in claim 15, further comprising:

driving the low spool with a starter/generator.

20. The method as recited in claim 15, further comprising:

driving a constant speed transmission with the low spool.