Abstract: A stator core having twelve stator poles, coils wound around the stator poles, and a hybrid type rotor are included. The stator poles inwardly and radially extended from an annular yoke portion. Each of the respective stator poles has the same number of inductors. The coils are connected so that a pair of the stator poles being substantially symmetric with respect to a point are excited in opposite polarities. The rotor is arranged with a predetermined air gap with respect to the inductors, the rotor has a pair of rotor cores each of which has rotor teeth facing to the inductors and a permanent magnet magnetized in the axial direction sandwiched therebetween. The angles between inductors at the corresponding positions of adjacent stator poles are defined by repeating three sets of angular distributions each of which includes three times of 29.1 degrees and one time of 32.7 degrees when a number of rotor teeth equals 100.

Abstract: A stator core having twelve stator poles, coils wound around the stator poles, and a hybrid type rotor are included. The stator poles inwardly and radially extended from an annular yoke portion. Each of the respective stator poles has inductors of the same number. The coils are connected so that a pair of the stator poles being substantially symmetric with respect to a point are excited in opposite polarities. The rotor is arranged with a predetermined air gap with respect to the inductors, the rotor has a pair of rotor cores each of which has rotor teeth facing to the inductors and a permanent magnet magnetized in the axial direction sandwiched therebetween. The angles between inductors at the corresponding positions of adjacent stator poles are defined by repeating three sets of angular distributions each of which includes three times of 29.1 degrees and one time of 32.7 degrees when a number of rotor teeth equals 100.

Abstract: A hybrid stepping motor in which each of two rotor yokes constituting a rotor is divided in its axial direction into at least two rotor yoke portions, the rotor yoke portions constituting one rotor yoke being made to abut on each other with their pole teeth shifted from each other in angular position by .theta..sub.0, the two rotor yoke portions belonging to the two rotor yokes respectively and sandwiching a permanent magnet therebetween being arranged with their pole teeth shifted from each other in angular position by 180/Nr degrees (.pi. radian in electric angle) under the condition that a relation of 0<.theta..sub.0 <90/Nr degrees is satisfied, and a rotor of a hybrid stepping motor in which two or more rotor units are arranged with their pole teeth shifted from each other in angular position by an angle smaller than 1/4 of the angular pitch with which the pole teeth are provided.