Disk drive spindle motor

Abstract

An improved spindle motor is provided for rotatably driving one or more memory storage disks in a computer disk drive or the like. The spindle motor comprises a stator shaft having opposite ends anchored to a disk drive housing, and a cylindrical rotor hub supported by bearings from the stator shaft for relatively high speed rotation. The stator shaft carries an armature in magnetically coupled relation with a high strength unitary permanent magnet sleeve carried by the rotor hub, with the number of armature poles and permanent magnet poles being mismatched to achieve low cogging motor operation. The memory disks have central openings therein and are mounted about the rotor hub for rotation during motor operation. Axially elongated resilient shim strips disposed about the rotor hub insure initial disk alignment with their inner diameter edges spaced from direct contact with the rotor hub, thereby permitting the hub and/or disks to accommodate normal thermal gradients during operation without positional shifting of the disks with respect to each other.

Dependencies are inferred from the claim text.