Motor

A motor comprising:

• a static section;
• a rotation section;
• and
• a bearing portion which supports the rotation section rotatably around a central axis;
• wherein
• the rotation section includes:
• a shaft extending along the central axis;
• an armature core including m×n teeth (m is an odd number equal to or more than 3, and n is a natural number equal to or more than 2) which are attached on the shaft and radially extend in the radial direction;
• a plurality of coils respectively provided on the m×n teeth;
• and
• a commutator electrically connected to the plurality of coils;
• the static section includes:
• field magnets including 2n magnetic poles facing the m×n teeth in the radial direction;
• and
• a brush group including at least a first-potential brush and at least a second-potential brush;
• the commutator includes a segment group defined by 2m×n segments which are arranged in a circumferential direction and in contact with the brush group;
• in at least a conducting wire defining each coil, each end portion thereof is connected to any one of the segments;
• in the segment group, a potential is cyclically increased or decreased between a first potential and a second potential in regard to the circumferential direction, due to the contact of the brush group and the commutator;
• m−1 segments are provided between the first-potential segment and the second-potential segment;
• the coils are connected in series between the first-potential segment and the second-potential segment via the segments;
• only the coil defined by winding a continuous conducting wire in a predetermined winding direction is disposed in each of k teeth among the m×n teeth;
• and
• only the coil defined by winding the continuous conducting wire in a direction reverse to the predetermined winding direction is disposed in each of teeth disposed at a position separated from each of the k teeth at 360×i degrees (i is a natural number equal to or less than (n−1)) of electric angles.