Abstract: A dynamoelectric machine intended for use as a three-phase spindle motor in a computer disc drive. The motor includes a stator having nine poles, only six being provided with coils. A rotor has eight permanent magnet poles that coaxially surround in operative relation the nine poles. The six windings are connected to define three discrete electrical phases.

Abstract: A motor structure and energization scheme provides a high efficiency electronically commutated reluctance motor that is characterized by less iron loss than conventional switched reluctance motors. The motor operates without the reversal of the flow of flux in the stator. Also, the flux switching frequency in the stator is minimized. By eliminating flux reversals and minimizing the flux switching frequency, the electronically commutated reluctance motor is operable over a wide range of speeds with improved efficiency. Structurally, the stator includes unevenly spaced poles which are grouped into pairs separated by a space related to the even spacing of the poles on the rotor. Adjacent pairs of poles on the stator are separated by a spacing which is not equal to the spacing between the poles of a pair. To provide for rotation of the rotor, each pair of poles on the stator is polarized to form poles of opposite polarity such that a magnetic circuit joins the two adjacent poles of the pair.

Abstract: A Motor structure and energization scheme provides a high efficiency electronically commutated reluctance motor that is characterized by less iron losses than conventional switched reluctance motors. The motor operates without the reversal of the flow of flux in the stator. Also, the flux switching frequency in the stator is minimized. By eliminating flux reversals and minimizing the flux switching frequency, the electronically commutated reluctance motor is operable over a wide range of speeds with improved efficiency. Structurally, the stator includes unevenly spaced poles which are grouped into pairs separated by a space related to the even spacing of the poles on the rotor. Adjacent pairs of poles on the stator are separated by a spacing which is not equal to the spacing between the poles of a pair. To provide for rotation of the rotor, each pair of poles on the stator is polarized to form poles of opposite polarity such that a magnetic circuit joins the two adjacent poles of the pair.