BRUSHLESS MOTOR AND DISK DRIVE APPARATUS

摘要

A brushless motor includes a stationary unit and a rotary unit rotatably supported with respect to the stationary unit. The stationary unit includes an armature and a base member arranged to support the armature. The rotary unit includes a magnet, a hub made of a magnetic material and a rotor yoke made of a magnetic material. The armature includes a plurality of coil patterns arranged along a circumferential direction. The hub includes an inner lower surface, an outer lower surface and a recess portion. The recess portion is arranged between the inner lower surface and the outer lower surface and depressed upward. At least a portion of the magnet is accommodated within the recess portion. At least one of the inner lower surface and the outer lower surface is positioned above a lower surface of the magnet.

主权项

1. A brushless motor, comprising:
a stationary unit; and a rotary unit rotatably supported with respect to the stationary unit, wherein the stationary unit includes a flat armature arranged to extend in a direction orthogonal to a center axis extending in an up-down direction and a base member arranged to support the armature, the rotary unit includes a magnet positioned above the armature, a hub made of a magnetic material and arranged to hold the magnet, and a rotor yoke made of a magnetic material and provided with a portion positioned below the armature, the armature includes a plurality of coil patterns arranged along a circumferential direction, the hub includes a lower surface and a recess portion depressed upward from the lower surface, at least a portion of the magnet accommodated within the recess portion, the recess portion includes an inner side surface positioned radially inward of the magnet and an outer side surface positioned radially outward of the magnet, and a radial gap exists between a radial inner end surface of the magnet and the inner side surface and/or between a radial outer end surface of the magnet and the outer side surface.