Systems and methods for driving an oil cooling fan of a gas turbine engine

• US 9,038,399 B2
• Filed: 09/04/2012
• Issued: 05/26/2015
• Est. Priority Date: 09/04/2012
• 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: MacFarlane, Ian A.
• Primary Examiner(s): Gatenberg, Ehud
• Assistant Examiner(s): PIKE, JARED WAYNE
• Application Number:
  US13/602,395
• Publication Number:
  US 20140060074A1
• Time in Patent Office: 994 Days
• Field of Search: 607/82, 607/83, 607/84, 607/85, 60/391.5
• US Class Current: 60/783
• CPC Class Codes: F02C 7/14 of fluids in the plant , e.g. lubricant or fuel F02C7/185 takes precedence
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Systems and methods for driving an oil cooling fan (36) of a gas turbine engine (10) during different modes of operation of the gas turbine engine (10) are described. A system may include a coupling device (40) configured to: transmit motive power from a power turbine shaft (22) of the gas turbine engine (10) to the oil cooling fan (36) during a first mode of operation where the power turbine shaft (22) is turning, and to decouple the oil cooling fan (36) from the power turbine shaft (22) during a second mode of operation where the power turbine shaft (22) is prevented from turning. An alternate source (42) of motive power may be configured to drive the oil cooling fan (36) during the second mode of operation.

Claims

1. A system for driving an oil cooling fan of a gas turbine engine, the system comprising:

a coupling device configured to;

transmit motive power from a power turbine shaft driven by a low pressure turbine of the gas turbine engine to the oil cooling fan during a first mode of operation where the power turbine shaft is turning, and to

decouple the oil cooling fan from the power turbine shaft during a second mode of operation where the power turbine shaft is prevented from turning; and

an alternate source of motive power configured to drive the oil cooling fan during the second mode of operation, the alternate source of motive power including a high pressure turbine of the gas turbine engine.

2. The system as defined in claim 1, wherein engine is an aircraft-mounted engine.

3. The system as defined in claim 1, wherein the alternate source of motive power includes an electric motor.

4. The system as defined in claim 3, wherein the electric motor is driven by a source of electricity powered by the high pressure turbine of the gas turbine engine.

5. The system as defined in claim 1, wherein an output of the alternate source of motive power is configured to be modulated based on a cooling load on an oil cooler of the gas turbine engine.

6. The system as defined in claim 1, wherein the alternate source of motive power is configured to vary the speed of the oil cooling fan based on a cooling load on an oil cooler of the gas turbine engine.

7. A gas turbine engine comprising:

a low pressure turbine coupled to a power turbine shaft;

an oil cooler including an oil cooling fan;

a coupling device configured to;

transmit motive power from the power turbine shaft of the gas turbine engine to the oil cooling fan during a first mode of operation where the power turbine shaft is turning, and to

decouple the oil cooling fan from the power turbine shaft during a second mode of operation where the power turbine shaft is prevented from turning; and

an alternate source of motive power configured to drive the oil cooling fan during the second mode of operation, the alternate source of motive power including a high pressure turbine of the gas turbine engine.

8. The gas turbine engine as defined in claim 7, wherein engine is an aircraft-mounted engine.

9. The gas turbine engine as defined in claim 7, wherein the alternate source of motive power includes an electric motor.

10. The gas turbine engine as defined in claim 9, wherein the electric motor is driven by a source of electricity powered by the high pressure turbine of the gas turbine engine.

11. The gas turbine engine as defined in claim 9, wherein the electric motor is configured to vary the speed of the oil cooling fan based on a cooling load on the oil cooler.

12. The gas turbine engine as defined in claim 7, wherein an output of the alternate source of motive power is configured to be modulated based on a cooling load on the oil cooler.

13. A method for driving an oil cooling fan of an oil cooler of a gas turbine engine, the method comprising:

driving the oil cooling fan using motive power extracted from a power turbine shaft driven by a low pressure turbine of the gas turbine engine during a first mode of operation where the power turbine shaft is turning; and

driving the oil cooling fan using motive power from an alternate source during a second mode of operation where the power turbine shaft is prevented from turning, the alternate source of motive power including a high pressure turbine of the gas turbine engine.

14. The method as defined in claim 13, wherein the alternate source comprises an electric motor.

15. The method as defined in claim 14, comprising driving the electric motor using power extracted from the high pressure turbine of the gas turbine engine.

16. The method as defined in claim 13, comprising modulating an output of the alternate source based on a cooling load on the oil cooler.

17. The method as defined in claim 13, wherein the second mode of operation comprises a hotel mode where the power turbine shaft is locked.