D.C. BRUSHLESS MOTOR WITH MINIMIZED NET RADIAL FORCES AND LOW COGGING TORQUE

摘要

A ten pole/twelve slot brushless DCmotor for a disk drive spindle includesa base; a cylindrical rotor structure ro-tating relative to the base and a gener-ally symmetrically slotted stator structurefixed about an axis of rotation. The ro-tor structure includes a permanent mag-net ring structure (56) defining ten perma-nently magnetized alternating north-southmagnet segments (56a-56j). The statorstructure includes a ferromagnetic core(60) defining twelve slots (65) betweentwelve stator poles (64). Coils of insulatedwire are wound around the stator polesin one of a plurality of winding patternsand connected into a series of phases, e.g.three phases.