Disk storage drive for maintaining precision during thermal variations

摘要

A disk storage drive is provided with a brushless drive motor having a stator (34) with a winding. An external rotor housing (32) including a permanent magnet (33) coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. A hub (31) is provided that is concentric to the rotor housing (32) and is connected to the rotor housing for rotation therewith. A bearing (47) above the stator rotatably supports an upper end of the rotor housing on a stationary shaft (46) and a bearing (37) below the stator braces the open end of the rotor housing by a ring element (35) having substantially the same heat expansion characteristics as the rotor housing (32).