Brazing procedure for generator liquid cooled stator bars

• US 5,796,189 A
• Filed: 01/23/1996
• Issued: 08/18/1998
• Est. Priority Date: 01/23/1996
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Lembke, Robert Timothy, Manning, Michael Patrick
• Primary Examiner(s): Ramsey, Kenneth J.
• Application Number:
  US08/589,923
• Time in Patent Office: 938 Days
• Field of Search: 310/71, 310/54, 228/183, 228/215, 228/179.1, 29/890.054
• US Class Current: 310/54
• CPC Class Codes: B23K 1/20 Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating preparation of surfaces in particular ways, see the relevant classes for the treatments or the materials treated, e.g. C04B, C23C
• CPC Class Codes: B23K 35/302 Cu as the principal constituent
• CPC Class Codes: H02K 15/0093 Manufacturing or repairing cooling fluid boxes, i.e. terminals of fluid cooled windings ensuring both electrical and fluid connection

Abstract

A method of creating a brazed joint between a plurality of solid and hollow strands of a stator bar and a stator bar end fitting comprising the steps of:

a) inserting between free ends of the plurality of solid and hollow strands a preformed braze alloy such that the braze alloy is at least flush with the free ends of the hollow and solid strands;

b) applying stop off material to free end edges of at least the hollow strands;

c) inserting the solid and hollow strands and preformed braze alloy in an opening of a stator bar end fitting;

d) heating the braze alloy to cause the braze alloy to flow about and between the solid and hollow strands and between the fitting and the solid and hollow strands, but wherein the stop off material prevents flow of braze alloy onto the free end edges of the hollow strands.

Claims

1. A method of creating a brazed joint between a plurality of solid and hollow strands of a stator bar and a stator bar end fitting comprising the steps of:

a) inserting between free ends of the plurality of solid and hollow strands a preformed braze alloy such that said braze alloy is at least flush with the free ends of said solid and hollow strands;

b) applying stop off material to free end edges of at least said hollow strands;

c) inserting the solid and hollow strands and preformed braze alloy in an opening of a stator bar end fitting;

d) heating said braze alloy to cause said braze alloy to flow about said solid and hollow strands and between an interior wall of said fitting and said solid and hollow strands, and wherein said stop off material prevents flow of braze alloy onto said free end edges of said hollow strands.

2. The method of claim 1 wherein said braze alloy projects beyond said free end edges.

3. The method of claim 1 wherein said brazing alloy is a copper phosphorus alloy.

4. The method of claim 1 wherein said opening in said stator bar end fitting is substantially rectangular in shape, and wherein said preformed braze alloy has a substantially complementary shape.

5. A brazed joint between a stator bar and an end fitting comprising:

a plurality of solid and hollow strands arranged in an array, said strands having free ends in substantially flush relationship with each other, and said array having a first cross-sectional shape;

an opening in the end fitting, the opening having a shape complementary to said first shape, said array received in said opening; and

a braze alloy joining free ends of said solid and hollow strands to each other and to an internal surface of said end fitting;

said braze alloy lying at least substantially flush with said free ends, and wherein end edges of said hollow strands are coated with stop-off material to limit the flow of braze alloy on said end edges.

6. The brazed joint of claim 5 wherein said braze alloy projects convexly beyond said free ends.

7. The brazed joint of claim 5 wherein said brazing alloy is a copper phosphorus alloy.

8. The brazed joint of claim 5 wherein said cross-sectional shape is substantially rectangular.