Turbine exhaust case and method of making

• US 20060010852A1
• Filed: 07/16/2004
• Published: 01/19/2006
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Original Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Inventors: Jutras, Martin, Gekht, Eugene, Fontaine, Mike
• Granted Patent: US 7,100,358 B2
• Time in Patent Office: Days
• US Class Current: 60/262
• CPC Class Codes: B23K 15/0093 characterised by the properties of the materials to be welded
• CPC Class Codes: B23K 15/04 for welding annular seams
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 26/28 of curved planar seams
• CPC Class Codes: F01D 25/162 Bearing supports
• CPC Class Codes: F01D 5/3061 by welding, brazing
• CPC Class Codes: F01D 7/00 Rotors with blades adjustable in operation; Control thereof for reversing F01D1/30
• CPC Class Codes: F01D 9/065 Fluid supply or removal conduits traversing the working fluid flow, e.g. for lubrication-, cooling-, or sealing fluids see also F01D25/16, F01D25/24 and F01D25/26
• CPC Class Codes: F02K 1/386 mixing devices in the jet pipe, e.g. for mixing primary and secondary flow
• CPC Class Codes: F02K 1/48 Corrugated nozzles
• CPC Class Codes: F05D 2230/232 by welding
• CPC Class Codes: F05D 2230/60 Assembly methods
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 29/4932 Turbomachine making
• CPC Class Codes: Y10T 29/49321 Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member

Abstract

A structural turbine exhaust case of a gas turbine engine, comprises inner and outer case portions; a bearing housing connected to the inner case portion for supporting a main spool of the gas turbine engine; and a plurality of airfoils extending between the inner and outer case portions, airfoils structurally connecting the inner case portion to the outer case portion.

Claims

1. A turbine exhaust case of a gas turbine engine, comprising:

inner and outer case portions defining an annual gas path therebetween, the inner case portion including a bearing housing portion adapted to support a main spool bearing of the gas turbine engine, the outer case including a connection apparatus for supportably connecting the turbine exhaust case to the gas turbine engine; and

a plurality of sheet metal airfoils extending between the inner and outer case portions, the sheet metal airfoils structurally connecting the inner case portion to the outer case portion and supporting inner case relative to outer case.

2. The turbine exhaust case as claimed in claim 1 further comprising an exhaust gas mixer connected to an aft end of the outer case portion.

3. The turbine exhaust case as claimed in claim 1 wherein the inner and outer case portions are sheet metal.

4. The turbine exhaust case as claimed in claim 1 wherein the bearing housing is forged.

5. A turbine exhaust case of a gas turbine engine, comprising:

inner and outer case portions;

a bearing housing connected to and supported by the inner case portion for supporting a main spool of the gas turbine engine;

a plurality of airfoils extending between the inner and outer case portions, the airfoils structurally connecting and supporting the inner case portion to the outer case portion; and

wherein the inner case portions are sheet metal.

6. The turbine exhaust case as claimed in claim 5 wherein the inner and outer case portions, bearing housing and airfoils are welded together, a weld fillet encircling a profile of a welded end of each of the airfoils and penetrating through an entire thickness of a wall of the respective inner and outer case portions.

7. The turbine exhaust case as claimed in claim 5 wherein the inner case comprises at least one smooth sheet metal bend portion adapted to stiffen the inner case portion.

8. A method of welding an end of a sheet metal airfoil to an annular case of a gas turbine engine, comprising:

inserting the end of the airfoil into a matingly-profiled opening of the case wall; and

applying a weld fillet extending along an periphery of the profiled opening and fully penetrating through an entire thickness of the case wall, wherein the case wall thickness is adapted to permit said full penetration.

9. The method as claimed in claim 8 wherein said end of the airfoil protrudes through said opening by a predetermined amount to form a protrusion, the predetermined amount being an amount which will be substantially consumed in the weld, such that substantially no protrusion remains after welding is completed.

10. The method as claimed in claim 8 wherein the weld fillet penetrates through substantially an entire thickness of the sheet metal of the case.

11. A method of fabricating a turbine exhaust case of a gas turbine engine, comprising:

providing inner and outer case portions with profiled openings therein;

providing a bearing housing for supporting a main spool of the gas turbine engine;

providing a plurality of sheet metal airfoils; and

brazing the bearing housing to the inner case portion and welding the respective airfoils at opposed ends thereof to the respective inner and outer case portions, thereby structurally connecting the inner and outer case portions to bear a load of the main spool of the engine supported by the bearing housing.

12. A method as claimed in claim 11 comprising steps of inserting one end of an airfoil into a corresponding profiled opening in the respective inner and outer case portions and forming weld penetrating through the an entire thickness of the respective case portions and penetrating through an entire thickness of the sheet metal of the airfoil.

13. A method as claimed in claim 12 wherein said end of the airfoil is inserted into the corresponding profiled opening from one side of the respective inner and outer case portions to have a predetermined portion of the airfoil protruding from the other side of the respective inner and outer case portions, the predetermined protruding portion being substantially consumed in weld.

14. A method as claimed in claim 13 wherein one of the laser beam and electron beam is applied to said end of the airfoil at said other side of the respective inner and outer case portions.

15. A method of welding a profiled sheet metal element to a metal host having a matingly-profiled opening therethrough, the method comprising the step of:

inserting an end profiled sheet metal element into the matingly-profiled opening from a first face Bide of the host such that a portion of the element protrudes through the opening and extends a height above a second face side of the host; and

applying a weld fillet from the second face side along a periphery of the opening;

wherein the protrusion height is selected so that the protruding portion is substantially consumed during the step of applying a fillet weld.

16. The method of claim 15 wherein the metal host has a thickness between the first and second face sides, and wherein the thickness is selected such that the step of applying a fillet results in full penetration through the host substantially around the opening.