Wall section for the working gas annulus of a gas turbine engine

Abstract

A seal segment is provided for a shroud ring of a rotor of a gas turbine engine. The seal segment is positioned, in use, radially adjacent the rotor. The seal segment has two or more spaced passageways. In use, a respective support bar can be contained within each passageway. The support bars allow attachment of the seal segment to the engine casing. Each passageway has an elliptical or substantially elliptical cross-section with a minor diameter and a major diameter, the minor diameter being substantially aligned with the radial direction. The respective support bar has a correspondingly elliptical or substantially elliptical cross-section for a close fit in the passageway.

1 . A wall section for the working gas annulus of a gas turbine engine, wherein the wall section has two or more spaced passageways such that, in use, a respective support bar is contained within each passageway, the support bars allowing attachment of the wall section to the engine casing, each passageway having an elliptical or substantially elliptical cross-section with a minor diameter and a major diameter, the minor diameter being substantially aligned with the radial direction, and the respective support bar having a correspondingly elliptical or substantially elliptical cross-section for a close fit in the passageway. 
     
     
         2 . A wall section according to  claim 1  which is a segment for a shroud ring of a rotor of a gas turbine engine, the seal segment being positioned, in use, radially adjacent the rotor. 
     
     
         3 . A wall section according to  claim 1  which is formed of ceramic. 
     
     
         4 . A wall section according to  claim 1  which is formed of ceramic matrix composite. 
     
     
         5 . A wall section according to  claim 1  which is formed of continuous fibre reinforced ceramic matrix composite. 
     
     
         6 . A wall section according to  claim 1 , wherein an abradable ceramic coating forms the annulus-facing surface of the wall section. 
     
     
         7 . A wall section according to  claim 1 , wherein a thermal barrier coating forms the annulus-facing surface of the wall section. 
     
     
         8 . A wall section according to  claim 1 , wherein the ratio of the major diameter to the minor diameter is 1.5 or more. 
     
     
         9 . A wall section according to  claim 1 , wherein the ratio of the major diameter to the minor diameter is 5 or less. 
     
     
         10 . A wall section according to  claim 1 , wherein the passageways extend in a fore and aft direction and are circumferentially spaced from each other. 
     
     
         11 . A wall section according to  claim 1  containing respective support bars in the passageways. 
     
     
         12 . A shroud ring of a rotor of a gas turbine engine, the shroud ring including an annular array of wall sections of  claim 1 , the wall sections being seal segments of the shroud ring. 
     
     
         13 . A gas turbine engine having the shroud ring of  claim 12 .