An electric motor comprising: a yoke having four poles of magnetic poles; a rotation shaft rotatably installed inside the yoke; an armature core having six teeth attached to the rotation shaft and radially extending in a radial direction, and six slots formed between the teeth; a coil wound on each of the teeth through an concentrated winding method; a commutator installed at the rotation shaft adjacent to the armature core and having eighteen segments disposed in a circumferential direction; a connecting wire connecting the segments opposite to each other with the rotation shaft as a center and having the same electric potential, and three brushes including a low speed brush and a high speed brush configured to supply power to the coil via the segments, and a common brush used in common with the low speed brush and the high speed brush (21 b), characterized in that: the coil wound on each of the teeth comprises one forward wound coil formed to be wound forward, and two reverse wound coils formed to be wound in reverse, when the teeth are allocated in the circumferential direction in sequence of a U phase, a V phase and a W phase, the forward wound coil wound on each of the phases is provided as the coil of the U phase, the V phase and the W phase, and the reverse wound coil wound on each of the phases is provided as the coil of a -U phase, a -V phase and a -W phase, the coils are electrically connected between the neighboring segments in the order of the U phase, the -W phase, the -W phase, the V phase, the -U phase, the -U phase, the W phase, the -V phase and the -V phase, the connecting wire is formed in series along with the coils of the U phase, the -W phase, the -W phase, the V phase, the -U phase, the -U phase, the W phase, the -V phase and the -V phase, the coil drawn between the armature core and the commutator is drawn around the rotation shaft in the same direction, and the coil and the connecting wire are wound around a riser formed at the segment by an α turn in the same direction to connect the segment and the coil. a yoke having four poles of magnetic poles; a rotation shaft rotatably installed inside the yoke; an armature core having six teeth attached to the rotation shaft and radially extending in a radial direction, and six slots formed between the teeth; a coil wound on each of the teeth through an concentrated winding method; a commutator installed at the rotation shaft adjacent to the armature core and having eighteen segments disposed in a circumferential direction; a connecting wire connecting the segments opposite to each other with the rotation shaft as a center and having the same electric potential, and three brushes including a low speed brush and a high speed brush configured to supply power to the coil via the segments, and a common brush used in common with the low speed brush and the high speed brush (21 b), the coil wound on each of the teeth comprises one forward wound coil formed to be wound forward, and two reverse wound coils formed to be wound in reverse, when the teeth are allocated in the circumferential direction in sequence of a U phase, a V phase and a W phase, the forward wound coil wound on each of the phases is provided as the coil of the U phase, the V phase and the W phase, and the reverse wound coil wound on each of the phases is provided as the coil of a -U phase, a -V phase and a -W phase, the coils are electrically connected between the neighboring segments in the order of the U phase, the -W phase, the -W phase, the V phase, the -U phase, the -U phase, the W phase, the -V phase and the -V phase, the connecting wire is formed in series along with the coils of the U phase, the -W phase, the -W phase, the V phase, the -U phase, the -U phase, the W phase, the -V phase and the -V phase, the coil drawn between the armature core and the commutator is drawn around the rotation shaft in the same direction, and the coil and the connecting wire are wound around a riser formed at the segment by an α turn in the same direction to connect the segment and the coil.