External corona shielding for an electrical machine

Patent metadata

Field	Value
Publication number	US-9543800-B2
Application number	US-201214351985-A
Country	US
Kind code	B2
Filing date	Sep 26, 2012
Priority date	Oct 26, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

An external corona shielding for a conductor bar of an electric machine, a main insulating layer sheath on the conductor bar. The shielding has a first ply, which sheaths the main insulating layer, and a second ply, which sheaths the first ply. Each ply is a conductive, impregnatable layer with a sliding layer, wherein the sliding layers of the two plies ( 20, 21 ) face one another. Each sliding layer has at least one cutout, wherein the two conductive layers are connected to one another through these cutouts with the aid of a permanently elastic, electrically conductive connection.

First claim

The invention claimed is:

1. An arrangement for external corona shielding comprising:
a conductor bar of an electric machine; a main insulating layer shielding the conductor bar;
an external corona shielding for the conductive bar comprising a first ply which sheaths the main insulating layer and a second ply which sheaths the first ply;
each of the first and second plies comprises a conductive, impregnatable layer provided with a respective sliding layer and the sliding layers on each of the two plies face one another; and
each of the sliding layers has a plurality of cutouts, the two conductive layers are mechanically and electrically connected to one another through the cutouts by a permanently elastic, electrically conductive connection, wherein the elastic, electrically conductive connection is formed by an adhesive joint between the facing sliding layers.

2. The arrangement as claimed in claim 1 , wherein the adhesive joint comprises a conductive adhesive.

3. The arrangement as claimed in claim 2 , wherein the adhesive comprises an electrically conductive silicone or an electrically conductive epoxy adhesive.

4. The arrangement as claimed in claim 1 , wherein each of the sliding layers has a large number of the cutouts;
the two conductive layers are connected to one another through the cutouts by a large number of permanently elastic, electrically conductive connections.

5. The arrangement as claimed in claim 1 , wherein at least one of the conductive layers comprises a strip fabricated from a woven material.

6. The arrangement as claimed in one of claim 1 , wherein at least one of the sliding layers is fabricated from polytetrafluoroethylene.

7. The arrangement as claimed in one of claim 1 , wherein at least one of the cutouts is produced by an etching operation.

8. The arrangement as claimed in one of claim 1 , wherein the plies together have a total thickness of approximately 0.3 mm.

9. A corona shielding strip for producing the external corona shielding of an arrangement as claimed in claim 1 , comprising:
a first ply, and a second ply which rests flat on the first ply;
each of the plies comprises a conductive, impregnatable layer;
a sliding layer on each of the conductive impregnatable layers, wherein the sliding layers face one another;
each of the sliding layers has at least one cutout and a permanently elastic, electrically conductive connection between the two conductive layers through the cutouts.

10. An electric machine comprising at least one arrangement as claimed in claim 1 .

11. The electric machine as claimed in claim 10 , wherein the external corona shielding comprises a corona shielding strip around the conductor bar, the shielding strip comprises:
a first ply, and a second ply which rests flat on the first ply;
each of the plies comprises a conductive, impregnatable layer;
a sliding layer on each of the conductive impregnatable layers, wherein the sliding layers face one another;
each of the sliding layers has at least one cutout and a permanently elastic, electrically conductive connection between the two conductive layers through the cutouts.

Assignees

• Siemens Ag

Inventors

• Brockschmidt Mario
• Kempen Stefan
• Pholmann Friedhelm
• Schmidt Guido
• Staubach Christian

Classifications

• H02K3/40 Primary

  for high voltage, e.g. affording protection against corona discharges · CPC title