Shroud segment and assembly with circumferential seal at a planar segment surface

• US 6,808,363 B2
• Filed: 12/20/2002
• Issued: 10/26/2004
• Est. Priority Date: 12/20/2002
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Noe, Mark Eugene, Darkins, Toby George Jr., Alford, Mary Ellen
• Primary Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US10/325,760
• Publication Number:
  US 20040120806A1
• Time in Patent Office: 676 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: 415/139
• CPC Class Codes: F01D 11/005 Sealing means between non relatively rotating elements
• CPC Class Codes: F01D 9/02 Nozzles; Nozzle boxes; Stator blades; Guide conduits , e.g. individual nozzles nozzle boxes F01D9/047

Abstract

A turbine engine shroud segment having a body including a circumferentially arcuate radially inner surface defining a circumferential arc and a radially outer surface is provided, at least at one axially spaced apart outer surface edge portion surface, with a surface depression extending circumferentially across the outer edge portion and including a planar seal surface. The planar seal surface is spaced apart radially outwardly from the circumferential arc defining a spaced apart chord of the arc. The planar seal surface is joined with the segment body radially outer surface through an arcuate transition surface. In a circumferential assembly of a plurality of the shroud segments into a turbine engine shroud assembly, at least one of the outer surface edge portions and its respective depression portion and fluid seal surface is distinct axially from an axially juxtaposed engine member by a separation therebetween. A fluid seal member, including a fluid seal surface matched in shape with the planar seal surface of the segment, is retained in juxtaposition for contact with the segment planar seal surface along the separation, for example as a result of pressure loading during engine operation.

Claims

1. A turbine engine shroud segment comprising a shroud body including a circumferentially arcuate radially inner surface defining a circumferential arc, and a radially outer surface extending between a first, axially forward, outer edge surface portion and a second, axially aft, outer surface edge portion axially spaced apart from the first outer surface edge portion, wherein at least one of the axially spaced apart outer surface edge portions comprises:

a surface depression portion extending circumferentially across the outer surface edge portion and including a planar seal surface;

the planar seal surface defining a chord of the circumferential arc defined by the shroud body radially inner surface, the chord being spaced apart radially outwardly from the circumferential arc;

the planar seal surface being joined with the shroud segment body radially outer surface through an arcuate transition surface.

2. The shroud segment of claim 1 in which the surface depression extends across the second, axially aft, outer surface edge portion.

3. The shroud segment of claim 1 in which the surface depression extends across the first, axially forward outer surface edge portion.

4. The shroud segment of claim 1 in which a surface depression extends across each of the first and second outer surface edge portions.

5. 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%.

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

7. The shroud segment of claim 5 in which the low ductility material is a monolithic ceramic.

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

the shroud segments comprise the shroud segment of claim 1 with at least one of the first and second axially spaced apart shroud body outer surface edge portions of a shroud segment being distinct axially from a surface of an axially juxtaposed adjacent engine member by a circumferential separation therebetween; and

,

a fluid seal member retained in the surface depression and extending circumferentially along and bridging the separation;

the fluid seal member including a fluid seal member surface in juxtaposition for contact with and matched in shape with the planar seal surface of the surface depression of the shroud segment along the separation.

9. The shroud assembly of claim 8 in which:

the plurality of shroud segments is a first number with the shroud segments assembled circumferentially, the shroud body arcuate radially inner surface defining a circle circumferentially;

the planar seal surfaces of the assembled shroud segments are axially spaced apart radially outwardly from the shroud body arcuate radially inner surfaces to define, radially outwardly about and spaced apart from the circle, a polygon shape having a second number of sides equal to the first number; and

,

a fluid seal member is retained at each segment depression portion seal surface with the respective seal surfaces of the fluid seal members and of the segment depression portions being in juxtaposition.

10. The shroud assembly of claim 8 in which the shroud segments are made of a low ductility material having a tensile ductility measured at room temperature to be no greater than about 1%.

11. The shroud assembly of claim 10 in which the low ductility material is a ceramic matrix composite material.

12. The shroud assembly of claim 10 in which the low ductility material is a monolithic ceramic.