Disk storage device with stator-rotor positioning providing improved

Abstract

A disk storage device that utilizes an inner rotor spindle motor in which the spindle shaft is fixed to the disk mounting hub and rotates therewith. Support for the spindle is provided by a bearing tube that has a greater diameter and greater rigidity than the stationary shaft or post typically employed to support the disk stack in an outer rotor arrangement. The bearing tube supports the bearings in which the spindle shaft is journalled and allows wider axial spacing between the bearings, reducing spindle run out. At the same time, the bearing tube functions to entrap contaminants from the bearings within the internal motor space and reduces contamination in the clean chamber. By configuring the inner rotor, including the disk support hub, to rotate around the outer diameter of the bearing tube, an elongated 'gap seal' is formed, allowing more efficient containment of contaminants from the bearings without need for expensive ferrofluidic seals. One end of the bearing tube extends into an internal cavity formed within the disk support hub. This arrangement requires the hub to have a hollow interior, providing for a rotor structure having further reduced mass, further improving acceleration and vibration characteristics of the spindle.