Blade track assembly with turbine tip clearance control

Patent metadata

Field	Value
Publication number	US-9926801-B2
Application number	US-201314137422-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Mar 14, 2013
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

An apparatus and method for controlling turbine blade tip clearance is disclosed herein. A blade track assembly can include a blade track carrier having a plurality of slots and rails defined by paths that vary in radial position as a function of circumferential location. An expansion ring can be operably coupled with the slots of the blade track carrier. A plurality of blade track segments can be operably coupled with the expansion ring and engageable with the rails of the blade track carrier such that expansion and contraction of the expansion ring causes radially outward movement and radially inward movement, respectively, of the blade track segments.

First claim

What is claimed is:

1. A turbine blade track assembly comprising
a blade track carrier having a top wall and a pair of sidewalls extending radially inward therefrom,
a plurality of slots formed in each sidewall of the blade track carrier, wherein each slot includes a first end located at a first radial position relative to an axis of rotation and a second end located at a second radial position outward of the first radial position,
a plurality of rails connected to each sidewall of the blade track carrier, each rail having a bearing surface extending between a first end and a second end, wherein the second end of the rail is positioned radially outward of the first end of the rail, wherein a path formed by each rail is a non-circular shape,
an expansion ring operably coupled with the slots of the blade track carrier, and
a plurality of blade track segments operably coupled with the expansion ring and engageable with the rails of the blade track carrier.

2. The turbine blade track assembly of claim 1 , wherein the expansion ring moves in a first circumferential direction during expansion and in an opposite circumferential direction during contraction.

3. The turbine blade track assembly of claim 2 , wherein each blade track moves in a circumferential direction in response to circumferential movement of the expansion ring.

4. The turbine blade track assembly of claim 2 , wherein each blade track segment slidingly moves along a bearing surface of a corresponding rail as the blade track segment moves in a circumferential direction.

5. The turbine blade track assembly of claim 1 , wherein each blade track segment moves radially inward and outward in response to the expansion ring moving radially inward and outward, respectively.

6. The turbine blade track assembly of claim 5 , wherein each blade track moves in both a radial direction and a circumferential direction as each blade track moves along a path of a corresponding rail.

7. The turbine blade track assembly of claim 1 , further comprising at least one fluid seal positioned between portions of the blade track assembly to substantially prevent fluid flow therethrough.

8. The turbine blade track assembly of claim 1 , further comprising at least one impingement hole formed in the top wall of the blade track carrier, a plenum formed between the top wall of the blade track carrier and a platform of the expansion ring, wherein a cooling fluid enters the plenum through the at least one impingement hole, and at least one cooling feed hole formed through the platform of the expansion ring for directing cooling fluid from the plenum toward the blade track segments.

9. A gas turbine engine comprising
a turbine blade track carrier having a top wall and a pair of sidewalls extending radially inward from the top wall,
a plurality of through slots formed in the sidewalls of the blade track carrier, each through slot extending circumferentially between first and second ends, wherein the first end of each slot is positioned radially inward of the second end of each slot,
a plurality of rails formed along the sidewalls of the blade track carrier, each rail extending circumferentially between a first and second ends, wherein the first end of each rail is positioned radially inward of the second end of each rail, wherein a path defined between the first and second ends of each rail is in a form of a spiral,
an expansion ring having a platform extending between a pair of side walls,
a plurality of bosses projecting radially outward from the platform of the expansion ring connectable with the slots of the blade track carrier,
a plurality of tabs projecting radially inward from the platform of the expansion ring, and
a plurality of blade track segments engageable with the rails of the blade track carrier and the tabs of the expansion ring.

10. The gas turbine engine of claim 9 , wherein each blade track moves radially inward and outward in response to radial contraction and radial expansion of the expansion ring, respectively.

11. The gas turbine engine of claim 9 , wherein each blade track slidingly engages a corresponding rail of the blade track carrier such that movement along the rail is defined by both a radial direction and a circumferential direction.

12. The gas turbine engine of claim 9 , further comprising a plurality of locating pins configured to couple the bosses of the expansion ring to the slots of the blade track carrier.

13. The gas turbine engine of claim 9 , further comprising at least one wear member positioned between moveably engaged potions of a blade track assembly, and at least one seal positioned in a fluid flow path.

14. The gas turbine engine of claim 9 , wherein each of the plurality of blade track segments includes a first wall, a second wall spaced apart from the first wall, and a bridge laterally extending between the first wall and second wall.

15. The gas turbine engine of claim 14 , further comprising a plurality of compliant clips and each of the plurality of compliant clips is engageable with corresponding tabs of the expansion ring and corresponding bridge of one of the blade track segments.

16. A method for controlling a turbine blade tip clearance comprising
controlling a diameter of an expansion ring with a cooling fluid,
moving the expansion ring in a circumferential direction as the diameter expands and contracts with a change in temperature,
moving a blade track in a circumferential direction with the expansion ring and guiding the blade track in a radial direction along a rail formed on a blade track carrier, and
coupling the expansion ring to a circumferentially extending elongate slot formed in a wall of the blade track carrier.

17. The method of claim 16 , wherein the slot is defined by a path that varies in radial position as a function of circumferential position.

18. The method of claim 16 , wherein the rail is formed in a spiral path relative to a centerline of a gas turbine engine.

Assignees

• Rolls Royce Corp

Inventors

• Uskert Richard C
• Lamusga Joseph P
• Sippel Aaron D

Classifications

• F05D2240/11

  Shroud seal segments · CPC title

• F01D25/246

  Fastening of diaphragms or stator-rings · CPC title

• Y02T50/672

  Cross-Sectional Technologies · mapped topic

• F01D11/24 Primary

  by selectively cooling-heating stator or rotor components · CPC title

• F01D11/22 Primary

  by mechanically actuating the stator or rotor components, e.g. moving shroud sections relative to the rotor · CPC title