Use of alumina paper for strain relief and electrical insulation in high-temperature coil windings

Patent metadata

Field	Value
Publication number	US-9520224-B2
Application number	US-201213585399-A
Country	US
Kind code	B2
Filing date	Aug 14, 2012
Priority date	Aug 14, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A coil ( 60 ). The coil ( 60 ) comprises a conductor formed in the shape of winding layers ( 68 ). The conductor comprises an insulating coating ( 96 ) surrounding a conductive core ( 94 ). The coil further comprises paper strips ( 80 ) disposed proximate one or more of the winding layers ( 68 ) to provide strain relief against mechanical forces exerted on the coil ( 60 ) and to provide electrical insulation between winding layers ( 68 ). In an embodiment where the coil ( 60 ) further comprises a core ( 70 ) the paper strips ( 80 ) are beneficially disposed at corners ( 70 A, 70 B, 70 C, and 70 D) of the core ( 70 ) and further between winding layers ( 68 ) at the corners ( 70 A, 70 B, 70 C, 70 D).

First claim

The invention claimed is:

1. A coil comprising:
a conductor formed in the shape of winding layers, the conductor comprising an insulating coating surrounding a conductive core; and
a coil core having a shape defining corners;
winding layers disposed around the coil core; and
paper disposed between the winding layer adjacent the coil core and the coil core at the corners, and between winding layers, the paper comprising aluminum dioxide fibers or strands disposed between one or more of the winding layers to provide both strain relief against mechanical forces exerted on the coil and electrical insulation between winding layers at temperatures up to 550 degrees C.; and
adhesive material, wherein the paper and the adhesive material are disposed between adjacent winding layers,
wherein the adhesive material is disposed between an outer surface of the coil core and the paper.

2. The coil of claim 1 wherein the aluminum dioxide fibers or strands define dimensions of about 0.25 inches wide, about 0.7 inches long and about 0.03 inches thick.

3. The coil of claim 1 wherein the coil core comprises a rectangular coil core, the paper disposed between one or more of the winding layers along a short face of the coil core.

4. The coil of claim 3 wherein the paper is disposed between the winding layers at the corners of the rectangular coil core.

5. The coil of claim 1 further comprising a ceramic insulating material covering exposed surfaces of the winding layers and exposed regions of the coil core.

6. The coil of claim 1 further comprising a ceramic insulating material covering exposed surfaces of the windings and exposed regions of the coil core.

7. The coil of claim 1 wherein the conductive core comprises a nickel clad copper conductive core and the insulating coating comprises a ceramic insulating coating.

Assignees

• Mcconkey Joshua S
• Siemens Energy Inc

Inventors

• Mcconkey Joshua S

Classifications

• H01F5/06

  Insulation of windings · CPC title

• H01F27/323 Primary

  Insulation between winding turns, between winding layers · CPC title