Gas turbine case and reinforcement strut for same

Patent metadata

Field	Value
Publication number	US-10227895-B2
Application number	US-201314135651-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 20, 2013
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

A case assembly for a gas turbine engine comprising annular case components each having a central axis. Radial struts each have a radial axis and intersect the annular case components. A stress dissipation mass projecting from a continuous surface of at least one of the struts at the intersection with a corresponding annular case component, the stress dissipation mass being on either side of a plane passing through the radial axis of the strut and the central axis of the corresponding annular case component. A method for dissipating thermal and mechanical stresses on a strut in a case assembly for a gas turbine engine is also provided.

First claim

The invention claimed is:

1. A case assembly for a gas turbine engine comprising:
annular case components each having a central axis, the annular case components including a splitter ring between a hub annular case component and an outer ring annular case component;
radial struts each having a radial axis, the radial struts intersecting the annular case components, a continuous and arcuate fillet projecting from a first portion of a continuous surface of at least one of the radial struts at an intersection with the splitter ring; and
a stress dissipation mass projecting from a second portion of the continuous surface in the at least one of the radial struts such that the stress dissipation mass is adjacent to the arcuate fillet, the stress dissipation mass being located at a leading portion of the at least one of the radial struts at the intersection with the splitter ring, the stress dissipation mass being on either side of a plane passing through the radial axis of the strut and the central axis of the annular case components, the stress dissipation mass being oriented radially inward of the splitter ring, the stress dissipation mass being a protuberance projecting from the fillet along the splitter ring at said leading portion, the stress dissipation mass sized and shaped such that the stress dissipation mass transfers thermal and mechanical stresses away from the leading portion, the splitter ring having a baffle at a leading end thereof, an edge of the baffle extending beyond the stress dissipation mass in a radially inward direction.

2. The case assembly as defined in claim 1 , wherein the stress dissipation mass and the strut are concurrently integrally machined from stock material of the strut.

3. The case assembly as defined in claim 1 , wherein the gas turbine engine is a turbofan engine having a fan case, an intermediate case downstream of the fan case, and wherein the annular case components are part of the intermediate case.

4. The case assembly as defined in claim 1 , wherein the strut has a flange that is welded along weld lines to the annular case component and the stress dissipation mass is spaced from the weld lines.

5. The case assembly as defined in claim 1 , wherein the stress dissipating mass has a pair of bulges on opposite sides of the plane, the bulges being symmetrical.

6. The case assembly as defined in claim 1 , comprising a fillet radius RL at the intersection between the radial struts and the annular case component featuring the stress dissipation mass, and wherein a length of the stress dissipation mass on either side of the struts is between RL and 2RL.

7. The case assembly as defined in claim 1 , wherein the stress dissipation mass is monolithic with the strut.

8. The case assembly as defined in claim 1 , wherein the intersection between the splitter ring and the leading portion of the at least one of the radial struts includes a fillet oriented radially outward of the splitter ring, the protuberance having a height taken along a radial direction relative to the central axis and a length taken along an axial direction relative to the central axis, the height and/or the length greater than that of the fillet.

9. A gas turbine engine comprising:
a case assembly having annular case components each having a central axis, the annular case components including a splitter ring between a hub annular case component and an outer ring annular case component,
radial struts in the case assembly, each having a radial axis, the radial struts intersecting the annular case components, a continuous and arcuate fillet projecting from a first portion of a continuous surface of at least one of the radial struts at an intersection with the splitter ring, and
a stress dissipation mass projecting from a second portion of the continuous surface in the at least one of the radial struts such that the stress dissipation mass is adjacent to the arcuate fillet, the stress dissipation mass being located at a leading portion of the at least one of the radial struts at the intersection with the splitter ring, the stress dissipation mass being on either side of a plane passing through the radial axis of the strut and the central axis of the annular case components, the stress dissipation mass being oriented radially inward of the splitter ring, the stress dissipation mass being a protuberance projecting from the fillet along the splitter ring at said leading portion, the stress dissipation mass sized and shaped such that the stress dissipation mass transfers thermal and mechanical stresses away from the leading portion, the splitter ring having a baffle at a leading end thereof, an edge of the baffle extending beyond the stress dissipation mass in a radially inward direction.

10. The gas turbine engine as defined in claim 9 , wherein the stress dissipation mass and the strut are concurrently integrally machined from stock material of the strut.

11. The gas turbine engine as defined in claim 9 , wherein the strut has a flange that is welded along weld lines to the annular case component and the stress dissipation mass is spaced from the weld lines.

12. The gas turbine engine as defined in claim 9 , wherein the stress dissipation mass has a pair of bulges on opposite sides of the plane, the bulges being symmetrical.

13. The gas turbine engine as defined in claim 9 , comprising a fillet radius RL at the intersection between the radial struts and the annular case component featuring the stress dissipation mass, and wherein a length of the mass on either side of the struts is between RL and 2RL.

14. The gas turbine engine as defined in claim 9 , wherein the stress dissipation mass is monolithic with the strut.

15. The gas turbine engine as defined in claim 9 , wherein the intersection between the splitter ring and the at least one of the radial struts includes a fillet oriented radially outward of the splitter ring, the protuberance having a height taken along a radial direction relative to the central axis and a length taken along an axial direction relative to the central axis, the height and/or the length greater than that of the fillet.

Assignees

• Pratt & Whitney Canada

Inventors

• Farah Assaf

Classifications

• F02C7/04

  Air intakes for gas-turbine plants or jet-propulsion plants · CPC title

• Y10T29/49233

  Repairing, converting, servicing or salvaging · CPC title

• F01D25/24 Primary

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F05D2260/941

  particularly aimed at mechanical or thermal stress reduction · CPC title