Methods and features for positioning a flow path assembly within a gas turbine engine

Abstract

Flow path assemblies having features for positioning the assemblies within a gas turbine engine are provided. For example, a flow path assembly comprises an inner wall and a unitary outer wall that includes an integral combustion portion and turbine portion, the combustor portion extending through a combustion section of the gas turbine engine and the turbine portion extending through at least a first turbine stage of a turbine section of the gas turbine engine. The flow path assembly further comprises at least two positioning members for radially centering the flow path assembly within the gas turbine engine. The positioning members extend to the flow path assembly from one or more structures external to the flow path assembly, constrain the flow path assembly tangentially, and allow radial and axial movement of the flow path assembly. Other embodiments for positioning flow path assemblies also are provided.

What is claimed is: 
     
       1. A flow path and positioning system assembly of a gas turbine engine, the flow path and positioning system assembly comprising:
 a flow path assembly comprising
 an inner wall; 
 a unitary outer wall including a combustor portion extending through a combustion section of the gas turbine engine and a turbine portion extending through at least a first turbine stage and a second turbine stage of a turbine section of the gas turbine engine, 
 wherein the turbine portion comprises
 an outer band of a nozzle portion of the first turbine stage, 
 a shroud of a blade portion of the first turbine stage, 
 an outer band of a nozzle portion of the second turbine stage, and 
 a shroud of a blade portion of the second turbine stage, and 
 
 the combustor portion and the turbine portion being integrally formed as a single unitary structure; and 
 
 a positioning system comprising
 at least two positioning members for centering the flow path assembly within the gas turbine engine, the at least two positioning members extending to the flow path assembly from one or more structures external to the flow path assembly, 
 
 wherein the at least two positioning members constrain the flow path assembly tangentially, and 
 wherein the at least two positioning members allow at least one of radial and axial movement of the flow path assembly. 
 
     
     
       2. The flow path and positioning system assembly of  claim 1 , further comprising a plurality of slots defined at an inner forward end of the flow path assembly, wherein each of the at least two positioning members extend axially into a respective one of the plurality of slots. 
     
     
       3. The flow path and positioning system assembly of  claim 2 , wherein the flow path assembly is free to move axially along the at least two positioning members. 
     
     
       4. The flow path and positioning system assembly of  claim 1 , wherein a first one of the at least two positioning members extends radially into a slot defined in a forward end of the unitary outer wall, and wherein a second one of the at least two positioning members extends radially to an outer surface of the unitary outer wall. 
     
     
       5. The flow path and positioning system assembly of  claim 1 , wherein the combustor portion of the unitary outer wall comprises an outer liner of a combustor of the combustion section. 
     
     
       6. The flow path and positioning system assembly of  claim 5 , wherein a first one of the at least two positioning members extends radially to an outer surface of the unitary outer wall at the shroud of the blade portion of the first turbine stage, and wherein a second one of the at least two positioning members extends radially to the outer surface of the unitary outer wall at the shroud of the blade portion of the second turbine stage. 
     
     
       7. The flow path and positioning system assembly of  claim 1 , wherein the combustor portion and the turbine portion are integrally formed from a ceramic matrix composite (CMC) material such that the unitary outer wall is a CMC component, and wherein the inner wall is formed from a CMC material. 
     
     
       8. The flow path and positioning system assembly of  claim 1 , wherein the at least two positioning members position the flow path assembly with respect to a fuel nozzle assembly of the gas turbine engine. 
     
     
       9. A flow path and positioning system assembly of a gas turbine engine, the flow path and positioning system assembly comprising:
 a flow path assembly comprising
 an inner wall; 
 a unitary outer wall including a combustor portion extending through a combustion section of the gas turbine engine and a turbine portion extending through at least a first turbine stage and a second turbine stage of a turbine section of the gas turbine engine, 
 wherein the turbine portion comprises
 an outer band of a nozzle portion of the first turbine stage, 
 a shroud of a blade portion of the first turbine stage, 
 an outer band of a nozzle portion of the second turbine stage, and 
 a shroud of a blade portion of the second turbine stage, and 
 
 the combustor portion and the turbine portion being integrally formed as a single unitary structure; and 
 
 a positioning system comprising
 a plurality of axial positioning members for positioning the flow path assembly within the gas turbine engine, 
 wherein the plurality of axial positioning members extend through a portion of the unitary outer wall and a portion of the inner wall, and 
 wherein some axial movement of the flow path assembly is allowed along the plurality of axial positioning members. 
 
 
     
     
       10. The flow path and positioning system assembly of  claim 9 , wherein the inner wall defines an inner wall flange at a forward end of the flow path assembly, wherein the unitary outer wall defines an outer wall flange at the forward end, and wherein the inner wall flange and the outer wall flange are positioned adjacent to one another. 
     
     
       11. The flow path and positioning system assembly of  claim 10 , wherein a plurality of slots are defined through the inner wall flange and the outer wall flange, and wherein one of the plurality of axial positioning members is positioned in one of the plurality of slots. 
     
     
       12. The flow path and positioning system assembly of  claim 9 , wherein the unitary outer wall defines an outer lip, and wherein the outer lip contacts an outer axial support. 
     
     
       13. The flow path and positioning system assembly of  claim 9 , wherein the inner wall defines an inner lip, and wherein the inner lip contacts an inner axial support. 
     
     
       14. The flow path and positioning system assembly of  claim 9 , wherein the combustor portion of the unitary outer wall comprises an outer liner of a combustor of the combustion section. 
     
     
       15. The flow path and positioning system assembly of  claim 9 , wherein the combustor portion and the turbine portion are integrally formed from a ceramic matrix composite (CMC) material such that the unitary outer wall is a CMC component, and wherein the inner wall is formed from a CMC material. 
     
     
       16. A flow path and positioning system assembly of a gas turbine engine, the flow path and positioning system assembly comprising:
 a flow path assembly comprising
 an inner wall; 
 a unitary outer wall including a combustor portion extending through a combustion section of the gas turbine engine and a turbine portion extending through at least a first turbine stage and a second turbine stage of a turbine section of the gas turbine engine, 
 wherein the turbine portion comprises
 an outer band of a nozzle portion of the first turbine stage, 
 a shroud of a blade portion of the first turbine stage, 
 an outer band of a nozzle portion of the second turbine stage, and 
 a shroud of a blade portion of the second turbine stage, and 
 
 the combustor portion and the turbine portion being integrally formed as a single unitary structure; and 
 
 a positioning system comprising
 a plurality of radial positioning members for positioning the flow path assembly within the gas turbine engine, 
 wherein each of the plurality of radial positioning members extends into one of a plurality of openings. 
 
 
     
     
       17. The flow path and positioning system assembly of  claim 16 , wherein the plurality of openings are each defined in a receptacle located on an outer surface of the unitary outer wall. 
     
     
       18. The flow path and positioning system assembly of  claim 16 , wherein the plurality of openings are defined through an outer surface of the unitary outer wall. 
     
     
       19. The flow path and positioning system assembly of  claim 16 , wherein each one of the plurality of radial positioning members extend from a mounting component external to the flow path assembly. 
     
     
       20. The flow path and positioning system assembly of  claim 16 , wherein the blade portion of the first turbine stage has a plurality of turbine blades each having a radially outer tip, and wherein the plurality of radial positioning members control thermal expansion along a radial direction to maintain a clearance gap between the unitary outer wall and the radially outer tip of each of the plurality of turbine blades.