PASSIVE CONTROL OF GAS TURBINE CLEARANCES USING CERAMIC MATRIX COMPOSITES INSERTS

• US 20200131922A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 06/11/2013
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: MONDAL, Bhaskar Nanda, RAHAIM, John Joseph, MONIZ, Thomas, ROSS, Steven A., KIRK, Joel, HUNTER, Scott, FUSINATO, Daniel
• Granted Patent: US 11,391,173 B2
• Time in Patent Office: Days
• CPC Class Codes: F01D 11/025 Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations
• CPC Class Codes: F01D 11/18 using stator or rotor components with predetermined thermal response, e.g. selective insulation, thermal inertia, differential expansion
• CPC Class Codes: F01D 25/005 Selecting particular materials
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F05D 2240/55 Seals
• CPC Class Codes: F05D 2260/30 Retaining components in desired mutual position
• CPC Class Codes: F05D 2300/5021 Expansivity
• CPC Class Codes: F05D 2300/6033 Ceramic matrix composites [CMC]
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A passive clearance control limits thermal expansion between stator components relative to rotor components. A control ring controls clearance in a passive manner and is located on or adjacent to stationary components which thermally expand during engine operation. The control ring is formed of material having low coefficient of thermal expansion such as CMCs (Ceramic Matrix Composites) and therefore limits, inhibits or restrains expansion of the adjacent stator components as temperatures increase. Limiting expansion of the stator component reduces rotor/stator clearances and limits parasitic leakage of fluid along the flowpath through the engine core.

Claims

1. A clearance control ring assembly, comprising:

a stator component disposed opposite a rotor component within a gas turbine engine;

a clearance control ring being formed of a single structure and extending circumferentially disposed radially outward of at least a portion of said stator component;

said clearance control ring having a coefficient of thermal expansion which is lower than said at least a portion of said stator component; and

wherein said at least a portion of said stator component is limited from thermal expansion and limited from growth from said rotor component.

2. The clearance control ring assembly of claim 1, wherein said clearance control ring is positioned on a compressor discharge pressure seal.

3. The clearance control ring assembly of claim 2, said stator component including an abradable material.

4. The clearance control ring assembly of claim 3, said rotor component including a labyrinth seal rotating adjacent said abradable material.

5. The clearance control ring assembly of claim 1, said clearance control ring disposed in said compressor.

6. The clearance control ring assembly of claim 5, said stator component including a blade ring.

7. The clearance control ring assembly of claim 6, said clearance control ring disposed outwardly and circumferentially about said blade ring.

8. The clearance control ring assembly of claim 7, said clearance control ring captured between a first aft case and a second aft case.

9. The clearance control ring assembly of claim 1, further comprising a mid-case ring disposed between aft case structures.

10. The clearance control ring assembly of claim 9, further wherein said clearance control ring is a first ring and a second ring separated by said mid-case ring and between said aft cases and a blade ring of said mid-case ring.

11. The clearance control ring assembly of claim 8, at least one surface of said control ring being angled relative to said engine axis.

12. The clearance control ring assembly of claim 8, further comprising one of a projection and a retaining shoulder on one of said first and second aft case and the other of said projection and said returning shoulder on said control ring, wherein said projection engages said retaining shoulder.

13. The clearance control ring assembly of claim 1, further comprising a first case and a second case, said first case and said second case each having a flange.

14. The clearance control ring assembly of claim 13, said control ring disposed at least one of said flanges.

15. The clearance control ring assembly of claim 13, further comprising a plurality of control wraps extending about said at least one flange.

16. The clearance control ring assembly of claim 13, further comprising a gap between said first flange and said second flange.

17. The clearance control ring assembly of claim 16, further comprising a rib extending into said gap.

18. The clearance control ring assembly of claim 17, further comprising a flange extending from control ring and engaging adjacent vane platforms.

19. The clearance control ring assembly of claim 8, wherein one of said first aft case and said second aft case has an angled engagement surface.

20. The clearance control ring assembly of claim 19, said control ring having an angled engagement surface slidably engaging said angled engagement surface of said one of said first and second aft case.

21. The clearance control ring assembly of claim 1, wherein said clearance control ring forms a blade ring.

22. The clearance control ring assembly of claim 1, said control ring forming a flange, said flange engaging said blade ring.