Gas turbine engine impeller system for an intermediate pressure (IP) compressor

Patent metadata

Field	Value
Publication number	US-9683488-B2
Application number	US-201314137453-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Mar 1, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A gas turbine engine includes a compressor assembly that is rotationally coupled to a shaft, the compressor assembly having a centrifugal impeller and a shroud covering a bladed portion of the centrifugal impeller. The compressor assembly includes a diffuser that is attached to the shroud via a pair of flanges, the diffuser including a strut that is mounted through an aft-extending leg to a base of an intercase. A sealing assembly is attached to the diffuser and is attachable to a transition duct that is positioned to receive air from the diffuser. The sealing assembly is configured to prevent air from passing through the sealing assembly while allowing relative motion to occur between the transition duct and the diffuser.

First claim

What is claimed is:

1. A gas turbine engine comprising:
a compressor assembly rotationally coupled to a shaft, the compressor assembly having a centrifugal impeller;
a shroud covering a bladed portion of the centrifugal impeller, the shroud having a first flange extending therefrom;
a diffuser having a second flange extending therefrom that is parallel to and in direct contact with the first flange, the diffuser attached to the shroud via the first flange and the second flange, the diffuser including a strut that is mounted through an aft-extending leg to a base of an intercase; and
a sealing assembly attached to the diffuser, wherein the sealing assembly is attachable to a transition duct that is positioned to receive air from the diffuser, and wherein the sealing assembly is configured to prevent air from passing through the sealing assembly while allowing relative motion to occur between the transition duct and the diffuser.

2. The gas turbine engine as claimed in claim 1 , wherein the diffuser comprises a radial portion and an axial portion that is generally orthogonal to the radial portion, and wherein the sealing assembly is attached to the axial portion of the diffuser.

3. The gas turbine engine as claimed in claim 1 , wherein the sealing assembly comprises at least one piston ring positioned in a cylinder, the piston ring is configured to slide relative to a wall of the cylinder and prevent air from passing while allowing the relative motion to occur.

4. The gas turbine engine as claimed in claim 1 , further comprising an aperture in the strut and an axial pass-through in the diffuser, wherein air that passes through the aperture also passes through the axial pass-through but without mixing with air that passes through the diffuser and directly from the compressor assembly.

5. The gas turbine engine as claimed in claim 4 , further comprising a non-load-bearing wall attached to the diffuser and attached to the strut, such that an enclosure is formed in part by the diffuser, the non-load-bearing wall, and the strut, wherein the air that passes through the aperture passes into the enclosure.

6. The gas turbine engine as claimed in claim 1 , comprising a thrust bearing aft of the impeller, wherein a portion of the thrust bearing is structurally attached to the strut.

7. A gas turbine engine comprising:
a shaft;
a turbine assembly rotationally coupled to the shaft, the turbine assembly driven by hot gases discharged from a combustion chamber;
a compressor assembly rotationally coupled to the shaft, the compressor assembly having a centrifugal impeller for pressurizing and impelling air into the combustion chamber;
a mounting structure coupled to a case of the gas turbine engine;
a thrust bearing attached to the mounting structure and attached to the shaft such that the shaft is rotatable relative to the mounting structure;
an impeller shroud covering a bladed portion of the centrifugal impeller, the impeller shroud having a first flange extending therefrom along a first extension;
a radial diffuser having a second flange extending therefrom along a second extension, the first extension in contact with the second extension, the radial diffuser positioned to receive compressed air from the compressor assembly, the radial diffuser having the second flange and having a first strut attached to the mounting structure, wherein the first flange of the impeller shroud is directly attached to the second flange via the first and second extensions;
a transition duct positioned to receive compressed air from the radial diffuser, the transition duct having a second strut attached to the mounting structure; and
a piston ring seal coupled between the transition duct and the radial diffuser, the piston ring seal configured to prevent air from passing through the seal while allowing relative motion between the transition duct and the radial diffuser.

8. The gas turbine engine as claimed in claim 7 , wherein the radial diffuser includes an elbow that directs the compressed air from passing in a radial direction to an axial direction, and wherein the piston ring seal is attached to the elbow.

9. The gas turbine as claimed in claim 7 wherein the piston ring seal comprises at least one piston ring positioned in a cylinder, the piston ring configured to slide relative to a wall of the cylinder and prevent the air from passing while allowing the relative motion to occur.

10. The gas turbine as claimed in claim 7 further comprising an aperture in the first strut and an axial pass-through in a radial portion of the radial diffuser, wherein air that passes through the aperture also passes through the axial pass-through but without mixing with air that passes through the radial portion of the radial diffuser and directly from the compressor assembly.

11. The gas turbine engine as claimed in claim 10 , further comprising a non-load-bearing wall attached to an axial portion of the radial diffuser and attached to the first strut, such that an enclosure is formed in part by the axial portion of the radial diffuser, the non-load-bearing wall, and the first strut, wherein the air that passes through the aperture passes into the enclosure.

12. The gas turbine engine as claimed in claim 7 , wherein the thrust bearing is positioned aft of the impeller.

13. A method of assembling a centrifugal compressor for a gas turbine engine comprising:
attaching a centrifugal impeller of a compressor to a rotational shaft;
covering a bladed portion of the centrifugal impeller with a shroud;
attaching a diffuser to the shroud via a pair of flanges, wherein one of the pair of flanges extends from the diffuser in a first direction and the other of the pair of flanges extends from the shroud in the first direction, and the pair of flanges are in direct contact with one another;
attaching the diffuser to an intercase via a strut that is mounted as an aft-extending leg to a base of the intercase; and
coupling the diffuser to a transition duct via a sealing assembly, wherein the sealing assembly is configured to prevent air from passing through the sealing assembly while allowing relative motion to occur between the transition duct and the diffuser.

14. The method as claimed in claim 13 , wherein attaching the diffuser comprises attaching a radial portion and an axial portion that is generally orthogonal to the radial portion, and wherein the sealing assembly is attached to the axial portion of the diffuser.

15. The method as claimed in claim 13 , wherein the sealing assembly comprises at least one piston ring positioned in a cylinder, the piston ring configured to slide relative to a wall of the cylinder and prevent the air from passing while allowing the relative motion to occur.

16. The method as claimed in claim 13 , further comprising forming an aperture in the strut and forming an axial pass-through in the diffuser, wherein air that passes through the aperture also passes through the axial pass-through but without mixing with air that passes through the diffuser and directly from the compressor.

17. The method as claimed in claim 16 , further comprising:
attaching a non-load-bearing wall to the diffuser and to the strut, such that an enclosure is formed in part by the diffuser, the non-load-bearing wall, and the strut, and such that the air that passes through the aperture passes into the enclosure; and
positioning a thrust bearing aft of the centrifugal impeller, wherein a portion of the thrust bearing is structurally connected to the strut.

18. The gas turbine engine as claimed in claim

Assignees

• Rolls Royce Nam Tech Inc
• Rolls Royce Plc

Inventors

• Ress Jr Robert A
• Swift Andrew

Classifications

• F02C3/08 Primary

  the compressor comprising at least one radial stage (F02C3/10 takes precedence) · CPC title

• F04D29/444

  Bladed diffusers · CPC title

• F05D2240/12

  Fluid guiding means, e.g. vanes · CPC title

• F04D29/624

  especially adapted for elastic fluid pumps · CPC title

• F05D2240/581

  Double or plural piston ring arrangements, i.e. two or more piston rings · CPC title