Shield for toroidal core electromagnetic device, and toroidal core electromagnetic devices utilizing such shields

Patent metadata

Field	Value
Publication number	US-9941047-B2
Application number	US-201615018099-A
Country	US
Kind code	B2
Filing date	Feb 8, 2016
Priority date	Dec 21, 2012
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A shield for a toroidal transformer that includes a toroidal assembly that comprises a toroidal magnetic core and a first winding includes a sheet of flexible non-magnetic conductive material. The sheet of flexible non-magnetic conductive material comprises a trunk portion extending along a longest dimension of the sheet of flexible non-magnetic conductive material and configured to wrap along an outer dimension of the toroidal assembly, and a plurality of fingers extending outwardly from the trunk portion and configured to wrap around portions of the first winding along portions of sides of the toroidal assembly in a direction towards the center of the toroidal magnetic core and folding into an inner dimension of the toroidal assembly.

First claim

We claim:

1. A toroidal transformer comprising:
a toroidal assembly having an outer dimension, an inner dimension, and two sides, the toroidal assembly comprising:
a toroidal magnetic core, and
a first winding wrapped around a portion of the toroidal magnetic core; and

a first shield wrapped over at least a portion of the first winding, the first shield comprising a flexible non-magnetic conductive sheet including:
a trunk portion extending along the outer dimension of the toroidal assembly, and
a plurality of fingers including a first set of multiple fingers and a second set of multiple fingers, the first set of multiple fingers extending from the trunk portion along portions of a first side of the two sides of the toroidal assembly in a direction towards the center of the toroidal magnetic core and folding into the inner dimension of the toroidal assembly, and the second set of multiple fingers extending from the trunk portion along portions of a second side of the two sides of the toroidal assembly in the direction towards the center of the toroidal magnetic core and folding into the inner dimension of the toroidal assembly such that ends of the first set of multiple fingers overlap ends of the second set of multiple fingers.

2. The toroidal transformer of claim 1 comprising:
a second winding wrapped over a portion of the first shield including a portion of the trunk portion and a portion of the plurality of fingers.

3. The toroidal transformer of claim 1 comprising:
an insulation layer wrapped over at least a portion of the first shield, wherein the insulation layer and the first shield are bonded together.

4. The toroidal transformer of claim 1 comprising:
an insulation layer wrapped over at least a portion of the first shield; and
a second shield wrapped over at least a portion of the insulation layer, the second shield comprising a second flexible non-magnetic conductive sheet including:
a second trunk portion extending around a portion of the insulating layer along the outer dimension of the toroidal assembly, and
a second plurality of fingers extending from the second trunk portion along portions of the two sides of the toroidal assembly in a direction towards the center of the toroidal magnetic core and folding into the inner dimension of the toroidal assembly.

5. The toroidal transformer of claim 1 , comprising:
an insulation layer wrapped over at least a portion of the first shield;
a second shield wrapped over at least a portion of the insulation layer, the second shield comprising a second flexible non-magnetic conductive sheet including:
a second trunk portion extending around a portion of the insulating layer along the outer dimension of the toroidal assembly, and
a second plurality of fingers extending from the second trunk portion along portions of the two sides of the toroidal magnetic core in a direction towards the center of the toroidal magnetic core and into the inner dimension of the toroidal assembly; and a second winding wrapped around a portion of the second shield including a portion of the second trunk portion and a portion of the second plurality of fingers.

6. The toroidal transformer of claim 1 , comprising;
a first insulation layer wrapped over at least a portion of the first shield;
a second shield wrapped over at least a portion of the first insulation layer, the second shield comprising a second flexible non-magnetic conductive sheet including:
a second trunk portion extending around a portion of the insulating layer along the outer dimension of the toroidal assembly, and
a second plurality of fingers extending from the second trunk portion along portions of the two sides of the toroidal magnetic core in a direction towards the center of the toroidal magnetic core and folding into the inner dimension of the toroidal assembly;

a second insulation layer wrapped over at least a portion of the second shield; and
a second winding wrapped around a portion of the second insulation layer and the second shield including a portion of the second trunk portion and a portion of the second plurality of fingers.

7. The toroidal transformer of claim 1 , wherein at least some of the plurality of fingers of the first shield have a portion adjacent the trunk portion and a portion distal the trunk portion, and wherein the portion adjacent the trunk portion is wider than the portion distal the trunk portion.

8. The toroidal transformer of claim 1 , wherein at least some of the plurality of fingers of the first shield have a tapered portion adjacent the trunk portion and a non-tapered portion distal the trunk portion.

9. The toroidal transformer of claim 8 , wherein the tapered portion has a first dimension substantially equal to the circumference of the outer dimension of the toroidal assembly divided by half the number of fingers in the plurality of fingers, and a second dimension substantially equal to the circumference of the inner dimension (π×inner dimension) of the toroidal assembly divided by half the number of fingers in the plurality of fingers.

10. The toroidal transformer of claim 8 , wherein the non-tapered portion has a dimension substantially equal to the circumference of the inner dimension of the toroidal assembly divided by half the number of fingers in the plurality of fingers.

11. The toroidal transformer of claim 1 , wherein at least some of the plurality of fingers of the first shield have a portion adjacent the trunk portion and a portion distal the trunk portion, and the trunk portion or the portion adjacent the trunk portion has rounded stress relief cutouts, or rounded stress relief cutouts cross from the portion adjacent the trunk portion into the trunk portion.

12. A shield for a toroidal transformer including a toroidal assembly comprising a toroidal magnetic core and a first winding, the shield comprising:
a sheet of flexible non-magnetic conductive material, the sheet comprising:
a trunk portion extending along a longest dimension of the sheet of flexible non-magnetic conductive material and configured to wrap along an outer dimension of the toroidal assembly, and
a plurality of fingers extending radially from the trunk portion in a first direction and configured to wrap around portions of the first winding along portions of a first side of the toroidal assembly in a direction towards the center of the toroidal magnetic core and to fold into an inner dimension of the toroidal assembly such that ends of the plurality of fingers overlap another portion of the sheet.

13. The shield of claim 12 comprising:
an insulation layer bonded to the sheet of flexible non-magnetic conductive material.

14. The shield of claim 12 , wherein at least some of the plurality of fingers have a portion adjacent the trunk portion and a portion distal the trunk portion, and wherein the portion adjacent the trunk portion is wider than the portion distal the trunk portion.

15. The shield of claim 12 , wherein at least some of the plurality of fingers have a tapered portion adjacent the trunk portion and a non-tapered portion distal the trunk portion.

16. The shield of claim 15 , wherein the tapered portion has a first dimension substantially equal to the circumference of the outer dimension of the toroidal assembly divided by half the number of fingers in the plurality of fingers, and a second dimension substantially equal to the circumference of the inner dimension of the toroidal assembly divided by half the number of fingers in the plurality of fingers.

17. The shield of claim 16 , wherein the non-tapered portion distal

Assignees

• Raytheon Co

Inventors

• Ortiz Joe A

Classifications

• H01F27/24

  Magnetic cores · CPC title

• H01F27/362 Primary

  Electricity · mapped topic

• H01F30/16

  Toroidal transformers · CPC title

• H01F27/2847

  Sheets; Strips (H01F27/2866 takes precedence) · CPC title

• H01F27/288 Primary

  Shielding · CPC title