Self starting multipole sync. or stepping motor - has anisotropic rotor with specified pole pair number

摘要

The rotor, for a multi-pole synchronous motor or stepping motor for two or more phases and with one or more stators, has the rotor magnets (2) made of anisotropic material whose preferred direction is radial perpendicular to the rotor shaft. Each half of the rotor circumference is thereby either a south or a north pole and the diametrically opposite poles have opposite polarity. With a single stator motor the number of stator pole pairs is equal to the number of rotor pole pairs multiplied by the number of phases. With a two-stator motor the stator pole pair number is equal to twice the rotor pole pair number minus one.