A rotor core has permanent magnets. Magnetic flux of the permanent magnet of an even-numbered rotor magnetic pole part is guided in an axial direction by an axial magnetic path member. Magnetic flux of the permanent magnet of an odd-numbered rotor magnetic pole part is guided into a soft magnetic inner cylindrical part. The axial end faces of the inner cylindrical part and the axial magnetic path member protrude from the rotor core in the axial direction and face a stationary magnetic path member with a small gap therebetween. The amount of magnetic flux of the magnet, which the permanent magnet applies to a stator core is adjusted by an excitation current of an excitation coil wound on the stationary magnetic path member.