Motor stator having transposed winding layers

• US 20060017347A1
• Filed: 07/20/2004
• Published: 01/26/2006
• Est. Priority Date: 07/20/2004
• Status: Active Grant

• Current Assignee: BluWav Systems LLC (Magna International Incorporated)
• Original Assignee: WaveCrest Laboratories LLC (Magna International Incorporated)
• Inventors: Rahman, Ziaur
• Granted Patent: US 7,365,468 B2
• Time in Patent Office: Days
• US Class Current: 310/208
• CPC Class Codes: H02K 3/18 Windings for salient poles
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An electric motor is provided with a multi-layered winding stator core configuration. A plurality of individual layers of wire strands are successively formed on each stator pole of a pole pair. Each winding layer is fabricated of the same relatively thin wire gauge. A first layer is applied directly on a pole and each successive layer is assembled on top of the last previous layer. Each layer of one pole of the pole pair is connected in series with a layer of the other pole of the pole pair to obtain a number of individual series coil connections equal in number to the number of layers. As inductance and resistance characteristics of the layers differ from each other as the layers increase in distance from each pole, layers from one pole of the pole pair are connected to respective layers different in order from that of the other pole pair.

Claims

1. A method of winding a stator core of an electric machine having at least one pole pair, the method comprising the steps of:

forming in successive order a predetermined number of individual layers of coiled wire strands on each pole of the pole pair segment; and

connecting in series each of said layers of a first pole of the pole pair with a layer of a second pole of the pole pair to obtain individual series coil connections on the pole pair equal in number to said predetermined number, wherein the order in which the layers in each series coil connection were formed are different from each other.

2. A method as recited in claim 1, wherein the machine stator comprises a plurality of pole pair segments that are separated and ferromagnetically isolated from each other, and said steps of forming and connecting are applied to each of the plurality of pole pairs segments.

3. A method as recited in claim 1, wherein:

said forming step comprises assembling a first layer directly on a pole and assembling each successive layer on top of the last previous layer, and said connecting step comprises joining the first layer formed on each pole of the pole pair to the last layer formed on the other pole to obtain a transposition of layer connections.

4. A method as recited in claim 3, comprising the additional step of connecting all of the series connections of the pole pair in parallel.

5. A machine stator comprising:

a core having a pair of poles;

a plurality of coil layers wound on each pole of said core, said layers successively overlaying each other in position about the pole, the layers of a first said pole connected to layers of a second said pole in inverse order to the position of the respective layers about the poles.

6. A machine stator as recited in claim 5, wherein the number of layers on each pole is the same and the connected layers form individual series circuits equal in number to the number of layers.

7. A machine stator as recited in claim 6, wherein each of the plurality of winding layers of both poles comprises the same number of coil turns.

8. A machine stator as recited in claim 6, wherein each of the series circuits comprises a layer from each pole and the series circuits are connected in parallel.

9. A machine stator comprising a plurality of pole pairs, each pair having a plurality of coil layers configured and connected as recited in claim 5.

10. A machine stator as recited in claim 9, wherein each of the plurality of pole pairs comprises a ferromagnetic core segment that is ferromagnetically isolated from each of the other pole pairs.