Electric machine, conductor guide and associated method

Patent metadata

Field	Value
Publication number	US-9812935-B2
Application number	US-201414463038-A
Country	US
Kind code	B2
Filing date	Aug 19, 2014
Priority date	Aug 19, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

An electric machine is provided. The electric machine includes a rotor and a stator. The stator includes a plurality of teeth and a plurality of windings. Each of the plurality of windings is positioned around at least one of the plurality of teeth. The electric machine further includes a leakage current shielding system. The leakage current shielding system includes a plurality of leakage current shields. Each of the current shields includes a body portion thereof which is positioned between the plurality of teeth and the plurality of windings. Each of the leakage current shields also includes a connecting portion that extends from the body portion. The leakage current shielding system also includes a plurality of connectors. Each of the plurality of connectors is adapted for receiving the connection portion of the leakage current shield. The leakage current shielding system also includes a connecting ring for securing the plurality of connectors.

First claim

What is claimed is:

1. An electric machine comprising:
a rotor;
a stator including a plurality of teeth defining a pocket between each adjacent tooth and a plurality of windings, each of said plurality of windings positioned around one of said plurality of teeth; and
a leakage current shielding system including:
a plurality of leakage current shields, each of said plurality of leakage current shields including a flexible body portion thereof, the body portion defining a body portion width thereof, the body portion being conformable from a planar shape to a body arcuate shape, the body portion of each leakage current shield positioned in one of the pockets and closely conforming to the adjacent teeth when in the body arcuate shape and a connecting portion integral with the body portion, the connecting portion defining a connecting portion width thereof the connecting portion width being substantially narrower than the body portion width of the body portion, the connecting portion extending from the body portion and conformable from a planar shape to a twisted shape in a connecting orientation substantially different from a body orientation of the connecting portion, the body orientation being the orientation of the connecting portion where the connecting portion connects to the body portion;
a connecting ring for securing a plurality of connectors; and
each of said plurality of connectors mounted to the connecting ring, positioned adjacent one of the plurality of windings and having a conductive portion that directly receives and secures the connecting portion of said leakage current shield when the connecting portion is in the twisted shape in the connecting orientation, the connecting portion being conformable to the connecting orientation while the body portion is in the body arcuate shape.

2. An electric machine in accordance with claim 1 , wherein said plurality of leakage current shields comprising a conductive layer coupled to a reference point having an electric potential that is not earth ground.

3. An electric machine in accordance with claim 2 , further comprising a terminal portion configured to couple said conductive layer to said reference point.

4. An electric machine in accordance with claim 1 , wherein each of said plurality of leakage current shields further comprises: a conductive layer; a first insulating layer positioned between at least one of said plurality of teeth and said conductive layer; and a second insulating layer positioned adjacent to said conductive layer, opposed to said first insulating layer.

5. An electric machine in accordance with claim 4 , wherein said conductive layer is coupled to a potential that is not earth ground and adapted to further facilitate reducing one or more of: a shaft voltage and a bearing current present in said electric machine, and electromagnetic interference (EMI) created by said electric machine.

6. An electric machine in accordance with claim 1 , wherein each of said plurality of leakage current shields is separated from each other.

7. An electric machine in accordance with claim 1 , wherein said leakage current shielding system further includes a conductor for connecting the leakage current shields to each other.

8. An electric machine in accordance with claim 7 , wherein said connectors are configured to receive the connecting portion of said leakage current shield in a first direction and to receive said conductor in a second direction, normal to the first direction.

9. An electric machine in accordance with claim 1 , wherein said electric machine is coupled to and controlled by a variable frequency drive circuit.

10. A leakage current shielding system for an electric machine, the electric machine having a stator having a plurality of stator teeth defining a pocket between each adjacent tooth, the machine includes a plurality of windings, each winding positioned around one of the plurality of stator teeth, said leakage current shielding system including:
a plurality of leakage current shields, each of said plurality of leakage current shields including a flexible body portion thereof, the body portion defining a body portion width thereof, the body portion being conformable from a planar shape to an arcuate shape, the body portion of each leakage current shield positioned in one of the pockets and closely conforming to the adjacent teeth when in the body arcuate shape and a connecting portion integral with the body portion, the connecting portion defining a connecting portion width thereof, the connecting portion width being substantially narrower than the body portion width of the body portion, the connecting portion extending from the body portion and conformable from a planar shape to a twisted shape in a connecting orientation substantially different from a body orientation of the connecting portion, the body orientation being the orientation of the connecting portion where the connecting portion connects to the body portion;
a connecting ring positioned adjacent the plurality of windings; and
a plurality of connectors, each of said plurality of connectors mounted to the connecting ring, positioned adjacent one of the plurality of windings and having a conductive portion that directly receives and secures the connecting portion of said leakage current shield when the connecting portion is in the twisted shape in the connecting orientation, the connecting portion being conformable to the connecting orientation while the body portion is in the body arcuate shape.

11. A leakage current shielding system in accordance with claim 10 , wherein said plurality of leakage current shields comprise a conductive layer coupled to a reference point having an electric potential that is not earth ground.

12. A leakage current shield in accordance with claim 11 , wherein the connecting portion of the leakage current shields include a terminal portion to facilitate the conduction of leakage current.

13. A leakage current shielding system in accordance with claim 10 , wherein each of said plurality of leakage current shields further comprises: a conductive layer; a first insulating layer positioned between at least one of said plurality of teeth and said conductive layer; and a second insulating layer positioned adjacent to said conductive layer, opposed to said first insulating layer.

14. A leakage current shielding system in accordance with claim 10 , wherein each of said plurality of leakage current shields is separated from each other.

15. A leakage current shielding system in accordance with claim 10 , wherein said leakage current shielding system further includes a conductor for connecting the leakage current shields to each other.

16. A leakage current shielding system in accordance with claim 15 , wherein said connectors are configured to receive the connecting portion of said leakage current shield in a first direction and to receive said conductor in a second direction, normal to the first direction.

17. A method for reducing leakage currents in an electric machine, said method comprising:
providing a plurality of individual leakage current shields, each of the plurality of leakage current shields made of a flexible sheet including a conductive core and opposed insulative coatings and including a body portion defining a body portion width thereof and a connecting portion defining a connecting portion width thereof, the connecting portion width being substantially narrower than the body portion width of the body portion;
removing the coatings from an end of the connecting portion of the plurality of leakage current shields to

Assignees

• Regal Beloit America Inc

Inventors

• Klopp Mark Lyon
• Stauffer Zachary Joseph
• Marks Michael Allen

Classifications

• H02K11/40

  Structural association with grounding devices · CPC title

• H02K11/022 Primary

  Electricity · mapped topic

• H02K11/014 Primary

  Shields associated with stationary parts, e.g. stator cores · CPC title