Disk storage device having spindle assembly with ring enclosure

摘要

A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor housing including a permanent magnet coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. A hub is provided that is concentric to the rotor housing and is connected to the rotor housing for rotation therewith. A bearing above the stator rotatably supports an upper end of the rotor housing on a stationary shaft and a bearing below the stator braces the open end of the rotor housing by a ring element having substantially the same heat expansion characteristics as the rotor housing.