Armature and armature manufacturing method

1. An armature comprising:

a core including a plurality of teeth extending in a radial shape with a slot formed between each adjacent pair of the plurality of teeth;

first winding coil sections formed in a plurality of layers by winding coil wire a plurality of times spanning different respective sets of at least two of the teeth, a winding start position of the coil of each of the plurality of layers being shifted by one slot each time, consecutively, toward a first direction in the circumferential direction of the core; and

second winding coil sections formed in a plurality of layers by winding coil wire a plurality of times spanning different respective sets of at least two of the teeth, a winding start position of the coil of each of the plurality of layers being shifted by one slot each time, consecutively, toward a second direction that is opposite to the first direction in the circumferential direction of the core,

wherein a winding start position of a first layer of the second winding coil sections is positioned at a slot where a first direction side end portion of a final layer of the first winding coil sections has been inserted, and

wherein the plurality of layers of the second winding coil sections are respectively shifted by one slot each time consecutively, toward the second direction.

2. The armature of claim 1 , wherein:

an end portion at one side in the core circumferential direction of a final wound layer among the plurality of the first winding coil sections is wound so as to be flat against one side face of one of the teeth, from a base end side to a leading end side of the one of the teeth.

3. The armature of claim 1 , wherein:

the plurality of teeth includes eighteen teeth;

the plurality of the first winding coil sections form 1 st layer to 4 th layer first winding coil sections, each wound a plurality of times spanning a different set of four of the teeth; and

the plurality of the second winding coil sections form 5 th layer to 9 th layer second winding coil sections that start winding at the slot where an end portion at the other side in the core circumferential direction of the 4 th layer first winding coil section has been inserted, the 4 th layer first winding coil section forming the final layer of the plurality of the first winding coil sections, and that are each wound a plurality of times spanning a different set of four of the teeth.

4. The armature of any one of claim 1 , wherein:

the plurality of the first winding coil sections and the plurality of the second winding coil sections are each wound across at least two of the teeth in a tightening direction.

5. The armature of any one of claim 1 , wherein:

the plurality of the first winding coil sections are each wound across a set of at least two of the teeth in a tightening direction; and

the plurality of the second winding coil sections are each wound across a set of at least two of the teeth in a loosening direction.

6. The armature of claim 1 , wherein:

the plurality of the first winding coil sections are each wound across a set of at least two of the teeth in a loosening direction; and

the plurality of the second winding coil sections are each wound across a set of at least two of the teeth in a tightening direction.

7. The armature of claim 1 , wherein:

the coil wire is wound in a clockwise direction in each layer of the plurality of layers of the first winding coil sections, and

the coil wire is wound in a counter-clockwise direction in each layer of the plurality of layers of the second winding coil sections.

8. The armature of claim 1 , wherein the first layer through the final layer of the first winding coil sections are disposed one after another from a lower side toward an upper side on the plurality of teeth and slots, and portions of the first layer through the final layer of the second winding coil sections are disposed one after another on the plurality of the layers of the first winding coil sections.

9. A method of manufacturing an armature comprising:

on a core including a plurality of teeth extending in a radial shape and with a slot formed between each adjacent pair of the plurality of teeth, forming a plurality of first winding coil sections with a plurality of layers by winding coil wire a plurality of times spanning different respective sets of at least two teeth, while shifting a winding start position of the coil wire of each of the plurality of layers one slot each time, consecutively, toward a first direction in the circumferential direction of the core; and

forming a plurality of second winding coil sections with a plurality of layers by winding coil wire a plurality of times spanning different respective sets of at least two teeth, while shifting a winding start position of the coil wire of each of the plurality of layers one slot each time, consecutively, toward a second direction that is opposite to the first direction in the circumferential direction of the core,

wherein a winding start position of a first layer of the second winding coil sections is positioned at a slot where a first direction side end portion of a final layer of the first winding coil sections has been inserted, and

wherein the plurality of layers of the second winding coil sections are respectively shifted by one slot each time consecutively, toward the second direction.

10. The method of manufacturing an armature of claim 9 , wherein:

the coil wire is wound in a clockwise direction in each layer of the plurality of layers of the first winding coil sections, and

the coil wire is wound in a counter-clockwise direction in each layer of the lurality of layers of the second winding coil sections.