High speed ten pole/twelve slot D.C. brushless motor with minimized net radial force and low cogging torque

摘要

A ten pole/twelve slot brushless DC motor for a disk drive spindle includes a base; a cylindrical rotor structure rotating relative to the base and a generally symmetrically slotted stator structure fixed about an axis of rotation. The rotor structure includes a permanent magnet ring structure defining ten permanently magnetized alternating north-south magnet segments. The stator structure includes a ferromagnetic core defining twelve stator slots between twelve stator poles. Coils of insulated wire are wound around the stator poles in one of a plurality of disclosed winding patterns and connected into a series of phases, e.g. three phases.