Shroud segment and assembly with surface recessed seal bridging adjacent members

• US 6,893,214 B2
• Filed: 12/20/2002
• Issued: 05/17/2005
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Noe, Mark Eugene, Darkins, Toby George, Alford, Mary Ellen
• Primary Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US10/325,779
• Publication Number:
  US 20040120808A1
• Time in Patent Office: 879 Days
• Field of Search: 415/136, 415/138, 415/139, 415/135, 415/173.1, 415/173.3, 415/200, 277/628, 277/630, 277/637, 277/643
• US Class Current: 415/138
• CPC Class Codes: F01D 11/005 Sealing means between non relatively rotating elements
• CPC Class Codes: F01D 9/04 forming ring or sector
• CPC Class Codes: F05C 2203/0839 of boron
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F05D 2250/131 polygonal
• CPC Class Codes: F05D 2300/21 Oxide ceramics
• CPC Class Codes: F05D 2300/2261 of silicon
• CPC Class Codes: F05D 2300/2283 of silicon
• CPC Class Codes: F05D 2300/50 Intrinsic material properties or characteristics
• CPC Class Codes: F05D 2300/603 Composites; e.g. fibre-reinforced

Abstract

A turbine engine shroud segment is provided with a radially outer surface including a pair of spaced apart, opposed first and second edge portion surface depressions, for example spaced circumferentially, having a seal surface shaped to receive, in a surface depression formed between assembled adjacent segments in a shroud assembly, or axially assembled adjacent segments and engine members, a radially outer fluid seal member. The depression portions of a shroud segment are joined with the radially outer surface of the shroud segment through an arcuate transition surface. Stresses generated during engine operation in the shroud material are reduced, enabling practical use of a low ductility material, for example a ceramic matrix composite. The edge portion surface depressions are provided with a first shape and the fluid seal member, disposed at the depression, is provided with a surface of a second shape matched in shape with the first shape.

Claims

1. A turbine engine shroud segment comprising a shroud segment body having a radially outer surface extending at least between a pair of first and second spaced apart, opposed outer surface end portions, wherein at least one of the first and second outer edge portions of the radially outer surface in the pair includes a surface depression portion including a depression portion seal surface of a first shape along the depression portion, the depression portion seal surface joined with the shroud body radially outer surface through an arcuate transition surface in which:

the pair of first and second outer surface end portions are spaced apart axially; and

,

the depression portion seal surface of the depression portion extends circumferentially along the depression portions.

2. The shroud segment of claim 1 in which the shroud segment includes a second pair of first and second outer surface end portions spaced apart circumferentially, with depression portion seal surfaces of the second pair extending axially.

3. The shroud segment of claim 1 in which the first shape of the depression portion seal surface is flat.

4. The shroud segment of claim 1 in which the shroud segment is made of a low ductility material having a tensile ductility measured at room temperature to be no greater than about 1%.

5. The shroud segment of claim 4 in which the low ductility material is a ceramic matrix composite material.

6. A turbine engine shroud assembly comprising a plurality of circumferentially disposed shroud segments, wherein:

each shroud segment comprises a shroud segment body made of a ceramic matrix composite material having a tensile ductility measured at room temperature to be no greater than about 1%, the shroud segment body having a radially outer surface extending at least between a pair of first and second spaced apart, opposed outer surface end portions, at least one of the first and second outer edge portions of the radially outer surface in the pair having a surface depression portion including a depression portion seal surface of a first shape along the depression portion, the depression portion seal surface joined with the shroud body radially outer surface through an arcuate transition surface, with the first and second outer edge portions of a shroud segment being distinct from a surface of a juxtaposed adjacent second member by a separation therebetween; and

,

a fluid seal member is retained in the surface depression portion and bridges the separation;

the fluid seal member including a fluid seal member surface of a second shape matched in shape with the first shape of the depression portion seal surface and in juxtaposition for contact with the depression portion seal surface along the separation;

the turbine engine shroud assembly including a seal retainer carried by a shroud hanger separate from and unsecured with the ceramic matrix composite material of the shroud segment body, the seal retainer applying a force to the fluid seal member toward the shroud segment to retain the fluid seal member in the surface depression portion.

7. The shroud assembly of claim 6 in which the fluid seal member is sufficiently flexible to enable contact with the depression portion seal surface.

8. The shroud assembly of claim 6 in which:

the pair of first and second outer surface edge portions are spaced apart circumferentially;

the shroud segments are disposed circumferentially with the depression portions of circumferentially adjacent first and second outer edge portions defining therebetween an axially extending surface depression including a depression seal surface of the first shape and an axially extending separation; and

,

the fluid seal member is disposed axially along the separation.

9. The shroud assembly of claim 6 in which both the first shape of the depression portion seal surface and the second shape of the fluid member seal surface is flat.

10. The shroud assembly of claim 6 in which the seal retainer carried by the shroud hanger is a stepped pin.

11. The shroud assembly of claim 10 in which the stepped pin comprises an enlarged head including a slot sized and shaped to receive and apply force to the fluid seal member.