Armature, dynamo-electric machine and manufacturing method of armature

1. An armature comprising:

a commutator;

an armature core that is rotatable together with the commutator and includes a plurality of teeth, which are arranged one after another at generally equal angular intervals; and

a plurality of windings, each of which is wound around corresponding two or more of the plurality of teeth and is connected to the commutator, wherein:

each circumferentially adjacent two of the plurality of windings partially circumferentially overlap with each other;

a total number of the plurality of windings is an even number;

the plurality of windings is divided into a first winding group and a second winding group;

the windings of the first winding group are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other; and

the windings of the second winding group are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other and are wound separately from the windings of the first winding group; and

each of the windings of the first winding group is diametrically opposed to and is generally parallel to a corresponding one of the windings of the second winding group.

2. The armature according to claim 1 , wherein:

the windings of the first winding group are wound starting from a first location; and

the windings of the second winding group are wound starting from a second location, which is different from the first location.

3. The armature according to claim 2 , wherein:

a total number of the windings in the first winding group is an odd number;

a total number of the windings in the second winding group is an odd number; and

the first location and the second location are displaced from each other by about 180 degrees.

4. The armature according to claim 1 , wherein the windings of the second winding winging group are wound after the windings of the first winding group are wound.

5. The armature according to claim 1 , wherein each of the windings of the first winding group and a corresponding one of the windings of the second winding group are wound at corresponding two different locations, which are most spaced from each other.

6. The armature according to claim 1 , wherein each of the windings of the first winding group and the windings of the second winding group is wound in two steps such that a first part of the winding, which is wound in a first step, and a second part of the winding, which is wound in a second step, are wound around common two or more of the plurality of teeth.

7. The armature according to claim 1 , wherein:

the windings of the first winding group are formed continuously from a first magnet wire; and

the windings of the second winding group are formed continuously from a second magnet wire.

8. The armature according to claim 1 , wherein the armature is part of a dynamoelectric machine.

9. A manufacturing method of an armature, comprising:

providing a commutator and an armature core, wherein the armature core is rotatable together with the commutator and includes a plurality of teeth, which are arranged one after another at generally equal angular intervals; and

forming a plurality of windings such that:

each of the plurality of windings is wound around corresponding two or more of the plurality of teeth and is connected to the commutator;

each circumferentially adjacent two of the plurality of windings partially circumferentially overlap with each other;

a total number of the plurality of windings is an even number;

the plurality of windings is divided into a first winding group and a second winding group;

the windings of the first winding group are wound with a first flyer of a double flyer armature winding machine and are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other; and

the windings of the second winding group are wound with a second flyer of the double flyer armature winding machine and are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other such that each of the windings of the first winding group is diametrically opposed to and is generally parallel to a corresponding one of the windings of the second winding group and are wound separately from the windings of the first winding group.

10. The manufacturing method according to claim 9 , wherein the forming of the plurality of windings includes forming the windings of the first winding group starting from a first location and forming the windings of the second winding group starting from a second location, which is different from the first location, and the forming of the windings of the first winding group at the first location and the forming of the windings of the second winding group at the second location are executed simultaneously.

11. The manufacturing method according to claim 10 , wherein:

a total number of the windings in the first winding group is an odd number;

a total number of the windings in the second winding group is an odd number; and

the first location and the second location are displaced from each other by about 180 degrees.

12. The manufacturing method according to claim 9 , wherein the forming of the plurality of windings includes forming the windings of the first winding group and thereafter forming the windings of the second winding group.

13. The manufacturing method according to claim 9 , wherein the forming of the plurality of windings includes forming each of the windings of the first winding group and a corresponding one of the windings of the second winding group at corresponding two different locations, respectively, which are most spaced from each other.

14. The manufacturing method according to claim 9 , wherein the forming of the plurality of windings includes forming each of the windings of the first winding group and the windings of the second winding group in two steps such that a first part of the winding, which is wound in a first step, and a second part of the winding, which is wound in the second step, are wound around common two or more of the plurality of teeth.

15. The manufacturing method according to claim 9 , wherein the forming of the plurality of windings includes:

forming the windings of the first winding winging group continuously from a first magnet wire; and

forming the windings of the second winding group continuously from a second magnet wire.

16. The manufacturing method according to claim 15 , wherein:

the forming of the windings of the first winding group includes feeding the first magnet wire from a first location; and

the forming of the windings of the second winding group includes feeding the second magnet wire from a second location, which is displaced from the first location by about 180 degrees.

17. An armature comprising:

a rotatable shaft;

a commutator that is fixed to the rotatable shaft;

an armature core that is fixed to the rotatable shaft, is adjacent to the commutator and includes a plurality of teeth, wherein the teeth are arranged one after another at generally equal angular intervals; and

a plurality of windings divided into a first winding group and a second winding group, wherein

each of the windings is wound around corresponding teeth and is connected to the commutator,

each of the windings of the first winding group is diametrically opposed to and is generally parallel to a corresponding one of the windings of the second winding group,

two circumferentially adjacent windings partially overlap with each other,

the windings of the first winding group are wound by a first flyer and are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other, and

the windings of the second winding group are wound by a second flyer, are wound separately from the windings of the first winding group, and are arranged one after another at generally equal angular intervals without circumferentially overlapping with each other.

18. The armature according to claim 17 , wherein

the windings of the first winding group are wound from a first starting location, and

the windings of the second winding group are wound from a second starting location, which is different from the first starting location.

19. The armature according to claim 18 , wherein

a total number of the windings in the first winding group is an odd number,

a total number of the windings in the second winding group is an odd number, and

the first location is located by about 180 degrees from the second location about the rotatable shaft.

20. The armature according to claim 17 , wherein the windings of the first winding group and the second winding group are wound in two steps such that a first part of the winding, which is wound in a first step, and a second part of the winding, which is wound in a second step, are wound around a common two or more of the teeth.