# US 2013/0156550 A1 · Mounting apparatus for low-ductility turbine shroud > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156550 A1 - Document ID: US20130156550A1 - Status: Published application - Kind: A1 - Application number: 13/327,349 - Filed: 2011-12-15 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: General Electric Company - Inventors: Michael John Franks; Jason David Shapiro; Samuel Ross Rulli; Roger Lee Doughty - Web page: https://patentgrep.com/patent/US20130156550A1 ## CPC - F01D 25/246: {Fastening of diaphragms or stator-rings} - F01D 11/08: for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20) - F01D 11/12: using a rubstrip, e.g. erodible. deformable or resiliently-biased part - F01D 5/284: {Selection of ceramic materials} - F01D 11/24: by selectively cooling-heating stator or rotor components - F05D 2240/11: Shroud seal segments - F05D 2250/41: with one degree of freedom - F05D 2260/38: by a spring, i.e. spring loaded or biased towards a certain position - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A shroud apparatus for a gas turbine engine includes: an annular metallic hanger; a shroud segment disposed inboard of the hanger, comprising low-ductility material and having a cross-sectional shape defined by opposed forward and aft walls, and opposed inner and outer walls, the walls extending between opposed first and second end faces, wherein the inner wall defines an arcuate inner flowpath surface; and a retainer mechanically coupled to the hanger which engages the shroud segment to retain the shroud segment to the hanger while permitting movement of the shroud segment in a radial direction. ## Claims ### Claim 1 A shroud apparatus for a gas turbine engine, comprising: an annular metallic hanger; a shroud segment disposed inboard of the hanger, comprising low-ductility material and having a cross-sectional shape defined by opposed forward and aft walls, and opposed inner and outer walls, the walls extending between opposed first and second end faces, wherein the inner wall defines an arcuate inner flowpath surface; and a retainer mechanically coupled to the hanger which engages the shroud segment to retain the shroud segment to the hanger while permitting movement of the shroud segment in a radial direction. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the retainer includes a central portion with a pair of opposed arms extending laterally outward therefrom. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein a surface of the retainer is clamped against the hanger, and the outer wall of the shroud segment is trapped between the hanger and a portion of the retainer. ### Claim 4 (depends on 3) The apparatus of claim 3 wherein a spring is clamped between the hanger and the retainer and resiliently bears against the shroud segment so as to urge it radially inboard against the retainer. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the inner wall extends axially forward past the forward wall to define a forward overhang and the inner wall extends axially aft past the aft wall to define an aft overhang. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the hanger is surrounded and carried by an annular turbine case. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein the hanger includes axially-spaced-apart forward and aft hooks which are received by forward and aft rails of the turbine case, respectively. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein the hanger has an annular body with a forward end disposed radially inboard relative to an aft end thereof. ### Claim 9 (depends on 8) The apparatus of claim 8 wherein the shroud segment includes a transition wall disposed between the forward and outer walls and extending at acute angles to both the forward and outer walls. ### Claim 10 (depends on 9) The apparatus of claim 9 wherein the transition wall extends generally parallel to the body of the hanger. ### Claim 11 (depends on 8) The apparatus of claim 8 wherein the hanger includes a resilient aft inner leg which resiliently loads the shroud segment axially forward against a bearing surface of a forward inner leg of the hanger. ### Claim 12 (depends on 1) The apparatus of claim 1 further comprising a hollow impingement baffle disposed inside the shroud segment. ### Claim 13 (depends on 12) The apparatus of claim 12 wherein a coolant feed passage extends through the hanger and connects to the interior of the impingement baffle. ### Claim 14 (depends on 1) The apparatus of claim 1 wherein the shroud segment comprises a ceramic matrix composite material. ### Claim 15 (depends on 1) The apparatus of claim 1 wherein an annular ring of shroud segments are arranged in an annular array within the casing. ### Claim 16 A shroud apparatus for a gas turbine engine, comprising: a shroud segment comprising low-ductility material and having an inner wall defining an arcuate inner flowpath surface and axially-spaced-apart forward and aft walls extending radially outward from the inner wall; wherein the inner wall extends axially past at least one of the forward wall or the aft wall to define an overhang. ### Claim 17 (depends on 16) The apparatus of claim 16 wherein the inner wall extends axially forward past the forward wall to define a forward overhang and the inner wall extends axially aft past the aft wall to define an aft overhang. ### Claim 18 (depends on 16) The apparatus of claim 16 wherein the shroud segment includes an outer wall spaced away from the inner wall and extending between the forward and aft walls. ### Claim 19 (depends on 18) The apparatus of claim 18 further including a transition wall disposed between the forward and outer walls and extending at acute angles to both the forward and outer walls. ### Claim 20 (depends on 16) The apparatus of claim 16 wherein an array of the shroud segments are arranged to form a closed annulus. ### Claim 21 (depends on 16) The apparatus of claim 16 wherein the shroud segment comprises a ceramic matrix composite material. ### Claim 22 (depends on 16) The apparatus of claim 16 further comprising an abradable coating disposed on the inner flowpath surface. ### Claim 23 (depends on 22) The apparatus of claim 22 wherein the coating includes a pattern of grooves therein. ### Claim 24 (depends on 23) The apparatus of claim 23 wherein the pattern includes a plurality of parallel side-by-side grooves. ### Claim 25 (depends on 23) The apparatus of claim 23 wherein the grooves are curved, each groove having a central portion disposed between forward and aft ends, the central portion being offset in a tangential direction relative to the forward and aft ends. ### Claim 26 A shroud apparatus for a gas turbine engine, comprising: an annular metallic hanger including an arcuate body and axially-spaced-apart forward and aft inner legs extending radially inward from the body, the forward inner leg including an arcuate forward bearing surface and the aft inner leg including an arcuate aft bearing surface; and a shroud segment disposed inboard of the hanger, comprising low-ductility material and having an inner wall defining an arcuate inner flowpath surface and axially-spaced-apart forward and aft walls extending radially outward from the inner wall; wherein the shroud segment is mounted relative to the hanger such that the forward bearing surface bears against the forward wall and the aft bearing surface bears against the aft wall, such that the shroud segment and the hanger cooperatively define a plenum therebetween. ### Claim 27 (depends on 26) The shroud apparatus of claim 26 further comprising a retainer mechanically coupled to the hanger which engages the shroud segment to retain the shroud segment to the hanger while permitting movement of the shroud segment in a radial direction. ### Claim 28 (depends on 26) The shroud apparatus of claim 26 wherein the aft inner leg resiliently loads the shroud segment axially forward against the forward bearing surface of the hanger.