Gas turbine engine mounting ring

Patent metadata

Field	Value
Publication number	US-9376935-B2
Application number	US-201213717898-A
Country	US
Kind code	B2
Filing date	Dec 18, 2012
Priority date	Dec 18, 2012
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A casing for an aircraft engine includes an outer ring and an inner hub defining an airflow passage therebetween, the outer ring having an axis defining an axial direction; a plurality of struts arranged in a circumferential array and extending radially from the inner hub to the outer ring to mount the inner hub to the outer ring; wherein the outer ring is defined by a double skin including an axially-extending annular outer skin of sheet metal concentrically surrounding and radially-spaced from an annular inner skin of sheet metal, the outer and inner skins generally parallel to one another, an annular front end ring and an annular rear end ring welded or brazed to the outer and inner skins adjacent respective front and rear edges of the skins to define an annular cavity between them, and the outer ring further comprising a plurality of circumferentially spaced axially-extending ribs interconnecting the outer and inner skins to reinforce the double skins.

First claim

The invention claimed is:

1. A casing for an aircraft engine, comprising:
an outer ring and an inner hub defining an airflow passage therebetween, the outer ring having an axis defining an axial direction;
a plurality of struts arranged in a circumferential array and extending radially from the inner hub to the outer ring to mount the inner hub to the outer ring; wherein the outer ring is defined by a double skin including an axially-extending annular outer skin of sheet metal concentrically surrounding and radially-spaced from an annular inner skin of sheet metal, the outer and inner skins generally parallel to one another, an annular front end ring and an annular rear end ring welded or brazed to the outer and inner skins adjacent respective front and rear edges of the skins to define an annular cavity between them, and the outer ring further comprising a plurality of circumferentially spaced axially-extending ribs interconnecting the outer and inner skins to reinforce the double skins; and
wherein each of the struts has a radial outer end mounted to an end boss connected to the outer ring, the end boss rigidly interconnecting the outer and inner skins.

2. The casing as defined in claim 1 wherein the bosses provide at least some of said axially-extending ribs.

3. The casing as defined in claim 2 wherein the ribs comprise at least two rib types, a first rib type provided by said end bosses and a second rib type disposed between adjacent end bosses.

4. The casing as defined in claim 1 wherein at least some of the axial ribs are radially inwardly depressions of the outer skin which are connected to the inner skin.

5. The casing as defined in claim 3 wherein the second rib type is a radially inwardly depression of the outer skin which is connected to the inner skin.

6. The casing as defined in claim 1 at least some of the axial ribs are an axially-extending plate positioned within the annular cavity and affixed to the respective outer and inner skins.

7. The casing as defined in claim 3 wherein the second rib type is an axially-extending plate positioned within the annular cavity and affixed to the respective outer and inner skins.

8. The casing as defined in claim 1 wherein the respective front and rear end rings comprise an annular wall having a thickness greater than a thickness of the respective outer and inner skins.

9. The casing as defined in claim 1 wherein the front and rear end rings each have U-shape cross-section with spaced apart arms extending axially welded or brazed to the inner and outer skins.

10. The casing as defined in claim 1 wherein each of the front and rear end rings is formed as a single butt-welded component.

11. The casing as defined in claim 2 wherein at least one of the end bosses projects radially outwardly from the outer skin to form a mounting pad to mount the engine to an aircraft.

12. The casing as defined in claim 1 wherein at least one of the front and rear end rings of the outer ring is configured for connection of the casing to an adjacent casing of the engine.

13. The casing as defined in claim 1 wherein at least one of the front and rear end rings of the outer ring has spaced therefrom an dedicated annular radially-extending flange for connection with an adjacent casing of the engine.

14. The casing as defined in claim 4 wherein each of the depressions defines an opening and comprises a welding fillet applied along an edge of the opening to weld a portion of the outer skin to the inner skin.

15. The casing as defined in claim 4 wherein the depressions each are affixed to the inner skin by at least one rivet.

16. The casing as defined in claim 4 wherein the depressions each have an axial length greater than a circumferential width.

17. An aircraft turbofan bypass engine having an intermediate casing disposed between a fan casing and a co-axially-disposed by-pass duct case and a compressor case, the intermediate casing comprising:
an outer ring and an inner hub defining an airflow passage therebetween;
a plurality of load bearing hollow struts arranged in a circumferential array and extending at least from the inner hub, radially to the outer ring, thereby mounting the inner hub to the outer ring; and
wherein the outer ring is formed as a toroid having an outer skin of sheet metal and an inner skin of sheet metal, a front end and a rear end of the toroid-shaped outer ring being closed by respective front and rear end components having a radial wall, the radial wall of the respective front and rear end components being thicker than each of the inner and outer skins, each of the hollow struts including a radial outer end formed with an end boss for mounting the outer end of the hollow strut to the outer ring, the end boss interconnecting the outer and inner skins, a plurality of circumferentially spaced axial ribs interconnecting the outer and inner skins to reinforce the toroid shaped outer ring, and the front and rear end components forming flanges with mounting holes for receiving fasteners to connect the fan casing and the by-pass duct case, respectively.

18. The aircraft turbofan bypass engine as defined in claim 17 wherein some of the ribs are radially inwardly depressions of the outer skin which are connected to the inner skin.

19. A method of making a mounting ring of a gas turbine engine, the mounting ring having at least one mounting boss to mount the engine to an aircraft when the mounting ring is installed in the engine, the method comprising:
providing an outer ring formed substantially in a double skin configuration having an outer skin of sheet metal surrounding and radially spaced apart from an inner skin of sheet metal;
interconnecting a respective front edge of the outer and inner skins with an annular front end ring;
interconnecting a respective rear edge of the outer and inner skins with an annular rear end ring;
using said at least one mounting boss and a plurality of end bosses of respective load bearing struts to interconnect the outer and inner skins, the load bearing struts being hollow, disposed in a circumferential array and extending radially to mount the outer ring to an inner ring disposed within the outer ring; said at least one mounting boss being formed at an outer radial end of one of the load bearing struts; and
interconnecting the outer and inner skins by radially positioning a plurality of circumferentially spaced axial ribs between the outer and inner skins to reinforce the double skin configuration of the outer ring.

20. The method as defined in claim 19 comprising a step of forming each of the axial ribs by radially and inwardly deforming a local portion of the outer skin to be connected to the inner skin.

Assignees

• Pratt & Whitney Canada

Inventors

• Eleftheriou Andreas
• Leclair Denis
• Denis David
• Menheere David
• Aitchison Paul

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F01D25/162 Primary

  Bearing supports · CPC title

• Y02T50/671

  Cross-Sectional Technologies · mapped topic

• F05D2230/60

  Assembly methods · CPC title

• Y10T29/4932

  Turbomachine making · CPC title