A rotor 55 having magnets 57 is assembled to rotate freely by bearings 58, 59 with respect to a stator which comprises coils 54 and stator cores 53. A current carrying device is formed from motor brushes 73, and slip rings 75 and commutator pieces 74 of a disk-shaped feeding unit 72, and the current carrying device is arranged on an outer side opposite to a side arranging the magnets 57 on a rotational axis X of the rotor 55 with respect to the bearing 58.