TURBINE SHROUD WITH BIASED BLADE TRACK

• US 20160102572A1
• Filed: 09/17/2015
• Published: 04/14/2016
• Est. Priority Date: 10/14/2014
• Status: Active Grant

• Current Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc)
• Inventors: O'Leary, Mark
• Granted Patent: US 9,945,243 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 11/08 for sealing space between rotor blade tips and stator specially-shaped blade tips therefor F01D5/20
• CPC Class Codes: F01D 11/12 using a rubstrip, e.g. erodible. deformable or resiliently-biased part
• CPC Class Codes: F01D 11/16 by self-adjusting means F01D11/12 takes precedence
• CPC Class Codes: F01D 25/24 Casings modified for heating or cooling F01D25/14; Casing parts, e.g. diaphragms, casing fastenings casings for rotary machines or engines in general F16M ; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F05D 2240/55 Seals
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A turbine shroud for a gas turbine engine is adapted to extend around a bladed turbine wheel and prevent gasses from passing over the blades without interacting with the blades. The turbine shroud includes a carrier, a blade track, and a plurality of biasing members. The biasing members locate the blade track relative to the carrier.

Claims

1. A turbine shroud for a gas turbine engine that extends around a central axis, the turbine shroud comprising

a metallic carrier that extends around the central axis,

a ceramic-containing composite blade track coupled to the metallic carrier, and

a plurality of biasing members arranged between the metallic carrier and the ceramic-containing composite blade track to bias the ceramic-containing composite blade track outwardly in a radial direction away from the central axis to locate the ceramic-containing composite blade track relative to the metallic carrier.

2. The turbine shroud of claim 1, wherein the plurality of biasing members are coil springs, leaf springs, or torsion springs.

3. The turbine shroud of claim 1, wherein the ceramic-containing composite blade track includes a plurality of blade track segments and each blade track segment includes a runner arranged radially inward of the metallic carrier that extends around a portion of the central axis, a retention head received in the carrier and engaged by the plurality of biasing members, and a neck that extends from the runner to the retention head.

4. The turbine shroud of claim 3, wherein the metallic carrier is formed to include a plurality of retention arms each arranged radially between at least a portion of a corresponding runner and a corresponding retention head of a blade track segment and each retention arm is engaged by at least one biasing member.

5. The turbine shroud of claim 4, further comprising at least three hard locators arranged between the retention head of each blade track segment and the metallic blade track sized to block movement of the blade track segment toward the central axis when the blade track segment reaches a predetermined position relative to the metallic carrier.

6. The turbine shroud of claim 4, wherein each retention arm is formed to include a slot that receives at least a portion of a biasing member to locate the biasing member relative to the metallic carrier.

7. The turbine shroud of claim 4, wherein each retention arm extends circumferentially around a portion of the central axis into a circumferentially-opening trough formed between the runner and the retention head of a blade track segment.

8. The turbine shroud of claim 1, wherein the metallic carrier is formed to include a plurality of retention arms each arranged radially between at least a portion of the ceramic-containing composite blade track and the central axis.

9. The turbine shroud of claim 8, wherein the plurality of biasing members engage the retention arms and the ceramic-containing composite blade track to bias the blade track away from the central axis.

10. The turbine shroud of claim 9, wherein each biasing member is a compression spring that pushes the ceramic-containing composite blade track outwardly in the radial direction away from the central axis.

11. The turbine shroud of claim 1, further comprising at least three hard locators arranged between the metallic carrier and the ceramic-containing composite blade track to block movement of the blade track toward the central axis when the blade track reaches a predetermined position in three dimensions relative to the metallic carrier.

12. The turbine shroud of claim 11, wherein the hard point locators are monolithically formed as part of the metallic carrier and extend outward in the radial direction away from the central axis from a supporting portion of the metallic carrier.

13. The turbine shroud of claim 11, wherein the hard point locators are monolithically formed as part of the ceramic-containing composite blade track and extend inward in the radial direction toward from the central axis from a supporting portion of the ceramic-containing composite blade track.

14. A turbine shroud that extends around a central axis, the turbine shroud comprising

a carrier,

a blade track segment coupled to the carrier, and

a plurality of biasing members arranged between the carrier and the blade track segment to bias the composite blade track segment outwardly in a radial direction away from the central axis to locate the blade track segment relative to the carrier.

15. The turbine shroud of claim 14, wherein the carrier is formed to include a plurality of retention arms each arranged radially between at least a portion of the blade track segment and the central axis.

16. The turbine shroud of claim 15, wherein each biasing member is a compression member that pushes the blade track segment outwardly in the radial direction away from the central axis.

17. The turbine shroud of claim 15, wherein the blade track segment is formed to include a runner arranged radially inward of the metallic carrier that extends around a portion of the central axis, a retention head arranged radially outward of the retention arms and engaged by the plurality of biasing members, and a neck that extends from the runner to the retention head.

18. The turbine shroud of claim 14, further comprising at least three hard locators arranged between the carrier and the blade track segment arranged to block movement of the blade track segment toward the central axis when the blade track segment reaches a predetermined position in three dimensions relative to the carrier.

19. A method of making a turbine shroud, the method comprising

mounting a ceramic-containing composite blade track segment to a metallic carrier so that a retention head of the blade track segment is received in the metallic carrier and a runner of the metallic carrier is located radially inward of the metallic carrier relative to a central axis about which the metallic carrier extends, and

arranging a plurality of biasing members between the blade track segment and the metallic carrier to bias the blade track away from the central axis.

20. The method of claim 19, further comprising machining at least three hard locators arranged between the carrier and the blade track segment to a calculated size to cause the hard locators to block movement of the blade track segment toward the central axis when the blade track segment reaches a predetermined position in three dimensions relative to the metallic carrier.