DC motor with concentrated windings having connecting wires run through armature slots

A dc motor comprising:

• a stator that comprises a plurality of field magnet poles;
• an armature core that comprises a plurality of teeth and slots formed between two adjacent teeth;
• an armature coil that comprises a plurality of concentrated winding coil units each individually wound on a different one of the teeth in the slots and a plurality of connecting wire units each electrically connecting two of the plurality of concentrated winding coil units;
• a commutator that is formed of a group of segments, and
• a brush that is in sliding contact with the segments for feeding the armature coil with electric power,
• wherein the group of segments of the commutator include first segments connected, respectively, with first ends of the concentrated winding coil units, second segments connected, respectively, with second ends of the concentrated winding coil units, and third segments connected only with the connecting wire units,
• wherein a pair of first and second segments connected to the same concentrated winding coil unit are placed adjacent to each other, and one of the third segments is disposed between two adjacent pairs of the first and second segments,
• wherein an mechanical angle of 45 degrees exists between adjacent two first segments, between adjacent two second segments and between adjacent two third segments, and
• wherein the plurality of connecting wire units include a connecting wire unit connected in such a manner that the connecting wire unit:
• (1) starts from one of the first segments;
• (2) passes through a slot formed between a first coil unit connected to the one of the first segments and a second coil unit adjacent to the first coil unit;
• (3) winds generally a half turn around the second coil unit;
• (4) connects to one of the third segments that is located a 120-degree mechanical angle away from the one of the first segment;
• (5) starts from the one of the third segments;
• (6) passes through a slot between a third coil unit adjacent to the second coil unit and a fourth coil unit adjacent to the third coil unit, the one of the third segments being located between second and first segments of the third and fourth coil units;
• (7) winds generally a half turn around the fourth coil unit and a fifth coil unit adjacent to the fourth coil unit;
• and
• (8) connects to one of the second segments located a 120-degree mechanical angle away from the one of the third segments.