Patent ID: 7755243

Claim:
A rotating electric motor comprising: a rotary shaft capable of rotation, a stator core formed in a cylindrical configuration, a rotor core fixed to said rotary shaft, a magnet set at said rotor core such that a pair of magnetic poles differing in magnetism are aligned in a radial direction of said rotor core, a field yoke provided at a perimeter of said stator core, and a winding that can control a magnetic flux density across said rotor core and said stator core by forming a magnetic circuit across said field yoke and said rotor core; wherein said rotor core includes a first rotor core of a cylindrical configuration, and a second rotor core provided in an inner circumference of said first rotor core, having a magnetic reluctance in an axial direction smaller than the magnetic reluctance of said first rotor core in the axial direction: wherein said first rotor core has a magnetic reluctance smaller in a circumferential direction and radial direction than in the axial direction, said stator core has a magnetic reluctance smaller in the circumferential direction and radial direction than in the axial direction.