Structure of rotors in stepping motors

A structure of a stepping motor, comprising:

• a stator;
• and
• a rotor comprising a magnetic component magnetized in its radial direction, said stepping motor being capable of forcing said rotor to rotate by magnetic force provided between magnetic poles of said rotor and excited salient poles of the stator, wherein
• a stator yoke of the stator is composed of a first stator yoke component and a second stator yoke component combined with each other in an axial direction,
• the first and second stator yoke components are arranged so that the two components are arranged with each other in a circumferential direction by an angle of either 90° or 80° and are made of a plurality of thin steel plates,
• a magnetic salient portion is provided inside the stator yoke, and a plurality of teeth are formed on the circumferential inner surface of the magnetic salient portion, and
• said magnetic component comprises:
• two magnetic component portions each shaped as an approximate gear, said two magnetic component portions have, on their circumferential surface, convex portions that extend in the axial direction and are disposed at appropriate spacing, said two magnetic component portions are either combined with each other or set up separately at appropriate spacing between them, and circular reentrant portions are formed at either side of the combined portion of said two magnetic component portions.