To solve the problem that a commutator is required in conventional DC rotary electric machines to convert the flowing orientation of a current in accordance with the rotation, and such a structure makes the DC rotary electric machine more complex and hard to manufacture, degrades its characteristics and increases its cost.

DC motors and DC generators excellent in structure, characteristics, cost and durability can be expected without using a commutator for changing the orientation of a current flow even though they are DC machines in principle, by changing the arrangement of a magnetic field in a stator and the disposition of wiring in a rotor to overcome defects in the conventional DC rotary electric machines.