Inner diffuser case for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-2016265371-A1
Application number	US-201415029474-A
Country	US
Kind code	A1
Filing date	Oct 31, 2014
Priority date	Nov 4, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

A combustor section of a gas turbine engine has a diffuser case with a structural cone having variable wall thicknesses strategically located for reducing localized stress in the cone.

First claim

What is claimed is:

1 . A diffuser case for use in a gas turbine engine, the diffuser case comprising:
a structural cone having a variable wall thickness configured to reduce thermal induced stress.

2 . The diffuser case of claim 1 , wherein the structural cone is centered about an axis, has a stress region subject to localized stresses, a compliance feature proximate the stress region, and a segment adjacent the compliance feature, and wherein the compliance feature has a first wall thickness that is less than a second wall thickness of the segment.

3 . The diffuser case of claim 2 , further comprising:
a strut projecting radially inward from and engaged to the structural cone, wherein the stress region is proximate the strut.

4 . The diffuser case of claim 3 , wherein the strut is hollow to facilitate airflow.

5 . The inner diffuser case of claim 2 further comprising:
a flange coupled to the structural cone; and,
wherein the compliance feature and the segment are included in a circumferentially continuous first portion, and the flange is disposed upstream from the first portion and centered about the axis.

6 . The diffuser case of claim 2 , wherein the first wall thickness is about thirty-five percent less than the second wall thickness.

7 . The diffuser case of claim 3 , further comprising:
a circumferentially continuous first portion having the compliance feature and the segment; a second portion engaged to and concentrically disposed downstream from the first portion; and, wherein the second portion includes the localized stress region.

8 . The diffuser case of claim 7 , further comprising:
an outer shroud centered about the axis; and, wherein the outer shroud is disposed radially inward from and engaged to the second portion and the strut projects radially inward from the outer shroud.

9 . The diffuser case of claim 7 , wherein the structural cone has a third portion engaged to and spanning axially between the flange and the first portion.

10 . The diffuser case of claim 9 , wherein the second portion and the third portion have respective wall thicknesses that are about equal to the second wall thickness and the first wall thickness is about fifteen to fifty percent less than the second wall thickness.

11 . The diffuser case of claim 9 , wherein the flange is substantially annular in shape and projects radially outward from the third portion.

12 . The diffuser case of claim 8 further comprising:
the strut being one of a plurality of struts being circumferentially spaced from one another and each substantially lying in an imaginary plane that intersect along the axis; and,
the localized stress region being one of a plurality of localized stress regions, each proximate a respective strut.

13 . The diffuser case of claim 7 , wherein the compliance feature is circumferentially continuous and the segment is circumferentially continuous, and wherein the segment is located axially between the compliance feature and the flange for structural rigidity of the flange.

14 . The diffuser case of claim 12 further comprising:
the segment being one of a plurality of segments spaced circumferentially from one another about the axis; and,
the compliance feature being one of a plurality of compliance features spaced circumferentially about the axis by respective adjacent segments.

15 . A combustor section of a gas turbine engine, the combustor section comprising:
a diffuser case having an annular structural cone concentric to an engine axis, the structural cone having a first wall thickness and a second wall thickness; and wherein the first wall thickness is less than the second wall thickness and the first wall thickness is proximate to a localized stress region in the structural cone.

16 . The combustor section of claim 15 further comprising:
an annular flange of the diffuser case engaged to and disposed upstream from the structural case;
a first portion of the structural cone having the first and second wall thicknesses;
a second portion of the structural cone located downstream of and concentric to the first portion; and,
wherein the second portion has the localized stress region.

17 . The combustor section of claim 16 further comprising:
a strut disposed radially inward from and extending radially outward for engagement to the second portion; and,
wherein the localized stress region is generally aligned circumferentially and disposed radially outward from the strut.

18 . The combustor section of claim 17 further comprising:
a compliant feature of the first portion having the first wall thickness;
a segment of the first portion having the second wall thickness; and,
wherein the compliant feature and the segment are circumferentially continuous and the compliant feature is spaced axially downstream from the flange by at least the segment.

19 . The combustor section of claim 17 further comprising:
the strut being one of a plurality of struts spaced circumferentially from one another; and,
a plurality of compliant features of the first portion each having the first wall thickness and wherein each one of the plurality of compliant features are circumferentially aligned and disposed radially outward from a respective strut of the plurality of struts.

20 . An inner diffuser case for use in a gas turbine engine, the inner diffuser case comprising:
a flange; a cone engaged to the flange, and having a stress region and a compliance feature disposed between the stress region and the flange; and, wherein the compliance feature is spaced from the flange for maintaining engagement integrity of the flange and structural rigidity of the cone.

Assignees

• United Technologies Corp

Inventors

• Dale Timothy
• Bhanderi Swati G

Classifications

• F05D2260/941

  particularly aimed at mechanical or thermal stress reduction · CPC title

• F01D25/246

  Fastening of diaphragms or stator-rings · CPC title

• F01D25/30

  Exhaust heads, chambers, or the like · 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

• F23R3/50

  Combustion chambers comprising an annular flame tube within an annular casing (toroidal combustion chambers F23R3/52) · CPC title