HEAT SHIELD WITH STRESS RELIEVING FEATURE

• US 20080072598A1
• Filed: 09/22/2006
• Published: 03/27/2008
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Patel, Bhawan B., Fish, Jason
• Granted Patent: US 7,775,047 B2
• Time in Patent Office: Days
• US Class Current: 60/734
• CPC Class Codes: F02C 7/222 Fuel flow conduits, e.g. manifolds
• CPC Class Codes: F02C 7/24 Heat or noise insulation air intakes having provisions for noise suppression F02C7/045; turbine exhaust heads, chambers, or the like F01D25/30; silencing nozzles of jet-propulsion plants F02K1/00
• CPC Class Codes: F05D 2230/237 Brazing
• CPC Class Codes: F05D 2230/642 using maintaining alignment while permitting differential dilatation
• CPC Class Codes: F05D 2250/182 crenellated, notched

Abstract

A heat shield for a fuel member of a gas turbine engine having at least one heat shield segment having a connection edge with at least one joint receiving portion defined therealong for receiving a welded joint attaching the heat shield segment to a fuel member, each joint receiving portion including a stress relieving feature defined along at least one end thereof.

Claims

1. A fuel injection system for a gas turbine engine, the system comprising:

a fuel conveying member adapted to circulate fuel therethrough, the fuel conveying member having a joint receiving member; and

a heat shield substantially covering the fuel conveying member, the heat shield having at least one connection edge fastened to the joint receiving member by at least one welded joint, and at least one stress relieving feature defined along the connection edge at least one end of the welded joint.

2. The fuel injection system as defined in claim 1, wherein the fuel conveying member is a manifold ring, and the joint receiving member includes a lip protruding from a surface of the manifold ring.

3. The fuel injection system as defined in claim 1, wherein the heat shield includes first and second heat shield segments cooperating to substantially cover the fuel conveying member, the at least one connection edge including first and second connection edges respectively defined by the first and second heat shield segments.

4. The fuel injection system as defined in claim 3, wherein the fuel conveying member is a manifold ring, the first heat shield segment covering a front portion of the manifold ring and the second heat shield segment covering a rear portion of the manifold ring.

5. The fuel injection system as defined in claim 1, wherein the joint receiving member receives at most one welded joint at any given location thereof.

6. The fuel injection system as defined in claim 1, wherein the at least one stress relieving feature includes a stress relieving feature defined adjacent each end of each welded joint.

7. The fuel injection system as defined in claim 1, wherein the stress relieving feature includes a notch defined through the heat shield along the corresponding one of the at least one connection edge.

8. The fuel injection system as defined in claim 1, wherein the welded joint is a brazed joint.

9. A heat shield for a fuel member of a gas turbine engine, the heat shield comprising at least one heat shield segment having a connection edge with at least one joint receiving portion defined therealong for receiving a welded joint attaching the heat shield segment to a fuel member, each joint receiving portion including a stress relieving feature defined along at least one end thereof.

10. The heat shield as defined in claim 9, wherein the stress relieving feature also reduce crack propagation from the end of the joint receiving portion.

11. The heat shield as defined in claim 9, wherein the means for reducing crack propagation of each joint receiving portion includes a notch defined through the heat shield segment along the connection edge thereof.

12. The heat shield as defined in claim 9, wherein the at least one heat shield segment includes two complementary heat shield segments cooperating to form an annular heat shield.

13. A method of manufacturing a fuel injection system, the method comprising:

forming a fuel conveying member with a joint receiving member included thereon;

forming at least one heat shield segment to surround the fuel conveying member;

forming at least one stress relieving feature in each heat shield segment along a connection edge thereof,

placing each heat shield segment around the fuel conveying member with the connection edge thereof adjacent the joint receiving member; and

joining each connection edge to the joint receiving member by forming at least one welded joint with at least one end thereof disposed adjacent a corresponding one of the at least one stress relieving feature.

14. The method as defined in claim 13, wherein forming the at least one stress relieving feature includes forming at least one notch through each heat shield segment along the connection edge thereof.

15. The method as defined in claim 13, wherein joining each connection edge includes forming the at least one welded joint with each end thereof disposed adjacent the corresponding stress relieving feature.

16. The method as defined in claim 13, wherein forming at least one welded joint includes forming at least one brazed joint.