To provide a hybrid stepping motor that has improved assemblability and motor characteristics by reducing the number of rotor cores in assembly of a multi-stage rotor.
A hybrid stepping motor includes: a first rotor core 4 that is assembled around a rotor shaft 1 and that has first rotor pole teeth 4a formed on an outer circumferential surface thereof; a first rotor magnet 6 that is assembled concentrically with the rotor shaft 1 in the vicinity of the first rotor pole teeth 4a; and second rotor cores 5 that are laminated through respective magnetic bodies 7 on two axial sides of the first rotor core 4, that are assembled around the rotor shaft 1, and that have respective second rotor pole teeth 5a formed on respective outer circumferential surfaces thereof. The first rotor core 4 is larger in axial thickness than each of the second rotor cores 5. A plurality of magnetic circuits are axially formed simultaneously in which magnetic flux of the first rotor magnet 6 flows from the first rotor pole teeth 4a through a stator pole teeth 8a facing the first rotor pole teeth 4a, the second rotor pole teeth 5a of each second rotor core 5 on each axial side, and each magnetic body 7, in that order, and returns to the first rotor magnet 6.
WANG DONG-HUI
SATO EISHIN
Takashi Okamura
Horimai Kazuharu
Yoshihiro Hirai
Masahiko Denda