System and method for removing rotor bow in a gas turbine engine using mechanical energy storage device

Patent metadata

Field	Value
Publication number	US-10760498-B2
Application number	US-201815861780-A
Country	US
Kind code	B2
Filing date	Jan 4, 2018
Priority date	Jan 4, 2018
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

The present disclosure is directed to a gas turbine engine structure and method for reducing or mitigating bowed rotor. The method includes coupling a rotor assembly to a mechanical energy storage device via a clutch mechanism when the rotor assembly is at or below a speed limit below an idle speed condition; storing mechanical energy at the mechanical energy storage device via rotation of the rotor assembly at or below the speed limit; releasing mechanical energy from the mechanical energy storage device to rotate the rotor assembly following shutdown of the gas turbine engine; and rotating the rotor assembly via the mechanical energy from the mechanical energy storage device.

First claim

What is claimed is:

1. A method for reducing thermal bowing in a gas turbine engine, the method comprising:
coupling a rotor assembly to a mechanical energy storage device via a clutch mechanism when the rotor assembly is rotating at or below a speed limit below an idle speed condition;
storing mechanical energy at the mechanical energy storage device from the rotor assembly rotating at or below the speed limit;
releasing the mechanical energy from the mechanical energy storage device to rotate the rotor assembly following shutdown of the gas turbine engine; and
rotating the rotor assembly via the mechanical energy from the mechanical energy storage device.

2. The method of claim 1 , wherein storing the mechanical energy at the mechanical energy storage device comprises:
displacing a mechanical energy displacement device of the mechanical energy storage device.

3. The method of claim 2 , wherein displacing the mechanical energy displacement device comprises:
compressing or tensioning a spring mechanically coupled to the rotor assembly, wherein decompressing or de-tensioning the spring induces rotation of the rotor assembly.

4. The method of claim 3 , wherein releasing the mechanical energy from the mechanical energy storage device comprises:
decompressing or de-tensioning the spring mechanically coupled to the rotor assembly.

5. The method of claim 2 , wherein displacing h mechanical energy displacement device comprises:
pressurizing a fluid within a pneumatic or hydraulic system, wherein changes in pressure of the fluid rotates the rotor assembly.

6. The method of claim 5 , wherein releasing the mechanical energy from the mechanical energy storage device comprises:
changing the pressure of the fluid within the pneumatic or hydraulic system to induce rotation of the rotor assembly.

7. The method of claim 1 , wherein releasing the mechanical energy from the mechanical energy storage device comprises intermittently releasing the mechanical energy to partially rotate the rotor assembly.

8. The method of claim 1 , wherein releasing the mechanical energy from the mechanical energy storage device comprises continuous release of the mechanical energy to at least partially rotate the rotor assembly.

9. The method of claim 8 , wherein the partial rotation of the rotor assembly comprises approximately 0.5 revolutions or less.

10. The method of claim 1 , further comprising:
decelerating rotation of the rotor assembly from above the speed limit to approximately zero revolutions per minute (RPM).

11. The method of claim 10 , wherein coupling the rotor assembly to the mechanical energy storage device comprises:
engaging a centrifugal clutch of the clutch mechanism at or below the speed limit, wherein the centrifugal clutch couples the rotor assembly to the mechanical energy storage device.

12. The method of claim 1 , wherein releasing the mechanical energy from the mechanical energy storage device rotates the rotor assembly following a first period of time during which a bowed rotor condition develops following shutdown of the gas turbine engineer.

13. The method of claim 1 , wherein the speed limit at or below which the rotor assembly is coupled to the mechanical energy storage device is less than or equal to 50% of the idle speed condition.

14. The gas turbine engine configured to reduce thermal bowing via the method of claim 1 , the gas turbine engine comprising:
the rotor assembly comprising a driveshaft and a rotor extended from the driveshaft; and
the mechanical energy storage device selectively couplable to the clutch mechanism, wherein the mechanical energy storage device is configured to couple the rotor assembly to the mechanical energy storage device via the clutch mechanism when the rotor assembly is at or below the speed limit below the idle speed condition, and wherein the mechanical energy storage device is configured to store mechanical energy via rotation of the rotor assembly at or below the speed limit, and wherein the mechanical energy storage device is configured to rotate the rotor assembly via mechanical energy released from the mechanical energy storage device.

15. The gas turbine engine of claim 14 , wherein the mechanical energy storage device comprises a spring coupled to the clutch mechanism, a timing mechanism, or both.

16. A gas turbine engine, the engine comprising:
a rotor assembly comprising a driveshaft and a rotor extended from the driveshaft; and
a mechanical energy storage device selectively coupled to a clutch mechanism to reduce or mitigate thermal bowing at the rotor assembly, wherein the mechanical energy storage device is configured to couple the rotor assembly to the mechanical energy storage device via the clutch mechanism when the rotor assembly is rotating at or below a speed limit below an idle speed condition, and wherein the mechanical energy storage device is configured to store mechanical energy from the rotor assembly rotating at or below the speed limit, and wherein the mechanical energy storage device is configured to rotate the rotor assembly via mechanical energy released from the mechanical energy storage device.

17. The gas turbine engine of claim 16 , wherein the mechanical energy storage device comprises a spring mechanically coupled to the rotor assembly, wherein decompressing or de-tensioning the spring releases mechanical energy to rotate the rotor assembly.

18. The gas turbine engine of claim 16 , wherein the mechanical energy storage device comprises a timing mechanism configured to intermittently rotate the rotor assembly via intermittent release of mechanical energy stored with the mechanical energy storage device.

19. The gas turbine engine of claim 16 , wherein the mechanical energy storage device comprises a fluid system configured to rotate the rotor assembly via changing a pressure of a fluid within the fluid system to induce rotation of the rotor assembly.

20. The gas turbine engine of claim 16 , wherein the clutch mechanism comprises a centrifugal clutch configured to selectively couple the rotor assembly to the mechanical energy storage device when the rotor assembly rotates at or below the speed limit.

Assignees

• Gen Electric

Inventors

• Cannella Andrew Bryan
• Orkiszewski Charles Stanley
• Dhabade Milind Chandrakant
• Sharma Praveen
• Drummond Brian
• Mittal Shivam

Classifications

• F02C7/275 Primary

  Mechanical drives · CPC title

• F02N5/02

  of spring type · CPC title

• F05D2260/42

  Storage of energy · CPC title

• F16D43/14

  with centrifugal masses actuating the clutching members directly in a direction which has at least a radial component; with centrifugal masses themselves being the clutching members · CPC title

• F01D25/34

  Turning or inching gear · CPC title