Fan motor with fluid dynamic bearing

摘要

A fan motor includes an integral bearing member ( 40 ') defining therein an axial inner bearing hole ( 21 ') and forming a ventilating path ( 25 ') in a wall portion thereof to communicate a bottom of the bearing hole with an exterior of the bearing member, a stator assembly ( 50 ) mounted to an outer periphery of the bearing member, and a rotor assembly ( 60 ) comprising a rotary shaft ( 68 ) extending into the bearing hole and a permanent magnet ( 66 ) confronting the stator assembly. Lubricating oil is filled between the rotary shaft and bearing member to establish dynamic pressure to separate the rotary shaft and the bearing member in radial direction when the rotary shaft rotates.