Anode, process for anodizing, anodized wire and electric device comprising such anodized wire

• US 6,261,437 B1
• Filed: 07/01/1999
• Issued: 07/17/2001
• Est. Priority Date: 11/04/1996
• Status: Expired due to Fees

• Current Assignee: ABB AB (ABB Limited)
• Original Assignee: Asea Brown Boveri AB (ABB Limited)
• Inventors: Kalldin, Hans-Olof, Hernnaes, Bo, Imrell, Torbjorn
• Primary Examiner(s): Enad, Elvin
• Application Number:
  US09/297,631
• Time in Patent Office: 747 Days
• Field of Search: 204/286, 205/124, 205/139, 205/138, 205/324
• US Class Current: 205/324
• CPC Class Codes: C25D 11/024 Anodisation under pulsed or modulated current or potential
• CPC Class Codes: C25D 11/04 of aluminium or alloys based thereon
• CPC Class Codes: H01F 41/122 Insulating between turns or between winding layers
• CPC Class Codes: H02K 15/00 Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
• CPC Class Codes: H02K 3/34 between conductors or between conductor and core, e.g. slot insulation
• CPC Class Codes: H02K 3/40 for high voltage, e.g. affording protection against corona discharges
• CPC Class Codes: H02K 3/44 Protection against moisture or chemical attack; Windings specially adapted for operation in liquid or gas

Abstract

An anode, process for anodizing, an anodized wire and electric device having an anodized wire for use in high-voltage electric machines. A predetermined length of metallic conductor wire is wound around a holder, where respective windings are separated from one another with guide cams and guide slots. The metallic conductor wire and holder are then disposed in an electrolyte, where both ends of the metallic conductor wire are connected to a positive pole on a current source so as to implement the anodization operation. An oxide layer is formed as a result of the anodizing operation on a metallic portion of the metallic conductor wire. Properties of the oxide layer are such that the electrical insulation properties and adherence of the oxide layer to the wire are suitable for use in windings of electric machines for high-voltage applications.

Claims

1. A batch anodization device for anodizing a metallic conductor wire having a predetermined length, comprising:

a holder configured to support and hold the metallic conductor wire at contact points in a predetermined position during an anodizing operation, said holder including at least three cam guides each having guide slots, said metallic conductor wire being spirally wound in the guide slots so as to be fixedly held, a separation space between respective of the guide slots in each turn being a predetermined distance,

said holder with said metallic conductor wire configured to be immersed in an electrolyte during said anodizing operation; and

a current source having a positive pole, respective ends of said metallic conductor wire connected to the positive pole of the current source during said anodizing operation, wherein

said holder including a central shaft and three bars arranged parallel to the central shaft and fixed to the central shaft by radially oriented arms.

2. The anode of claim 1, wherein:

the at least three guide cams being made of an electrically conducting material.

3. The anode of claim 2, wherein:

respective of the at least three guide cams being connected to the positive pole of the current source.

4. The anode of claim 1, wherein:

said metallic conductor wire comprising aluminum.

5. The anode of claim 1, wherein:

said metallic conductor wire including copper.

6. A method for anodizing a metallic conductor wire having a predetermined wire length, comprising steps of:

spirally winding said metallic conductor wire onto a holder having at least three guide cams with guide slots, including

spirally winding the metallic conductor wire on the holder to form turns that are fixed held at contact points by the guide slots such that the turns of the metallic conductor wire being spaced apart by a predetermined distance, said holder having a central shaft and bars arranged in parallel to the central shaft, the bars being connected to the central shaft by radially oriented arms;

connecting both ends of said metallic conductor wire to a positive pole of a current source; and

immersing said metallic conductor wire on said holder into an electrolyte.

7. The method of claim 6, further comprising:

varying at least one process parameter during the anodizing operation for generating an oxide layer that fixedly adheres to an underlying metal portion of said metallic conductor wire, said oxide layer having a thickness less than 15 μ

m.

8. The process of claim 7, wherein:

said varying step includes controlling an electrochemical process parameter according to a predetermined cycle during the anodizing operation.

9. The process of claim 7, wherein:

said varying step includes varying a temperature during the anodizing operation.

10. An anodized conductor wire comprising:

a metallic conductor wire having a predetermined length;

an oxide layer disposed on said metallic conductor wire by batch anodizing of the metallic conductor wire, said oxide layer being thin and exhibiting a structure and adhesion to an underlying metal portion of said metallic conductor wire so as to be configured for continued adhesion to the underlying metal portion when said metallic conductor wire being shaped for use in at least one of a coil and a winding of a high-voltage electric machine;

said oxide layer having an electrically insulating property configured to electrically insulate respective strands of a winding in the high-voltage electric machine, wherein

said oxide layer being formed by batch anodizing when said metallic conductor wire being wound on a holder having at least three cam guides with guide slots, a central shaft and bars arranged in parallel to the central shaft and fixed to the central shaft by radially oriented arms, contact surfaces between said holder and said metallic conductor wire being contact points, said guide slots separating respective turns of said metallic conductor wire when spirally wound and immersed into an electrolyte and when both ends of said metallic conductor wire being connected to a positive pole of a current source.

11. The anodized conductor wire of claim 10, wherein:

said oxide layer being less than 15 μ

m.

12. The anodized conductor wire of claim 10, wherein:

said metallic conductor wire comprising aluminum.

13. The anodized conductor wire of claim 10, wherein:

said metallic conduct wire comprising copper.