A motor includes a support member (40) having a bearing housing (20)
defining a bearing hole (21) therein, a stator assembly (50) mounted to
an outer periphery of the support member, and a rotor assembly (60)
having a rotary shaft (68) extending into the bearing hole and a
permanent magnet (66) confronting the stator assembly. A bearing pattern
(100) is formed on either of the bearing housing and the rotary shaft.
The bearing pattern includes a number of first and second grooves (13,
16) arranged circumferentially in an alternate fashion. Each of the first
grooves is in communication with one adjacent second groove at an edge of
the bearing pattern. Lubricating oil filled in the bearing pattern to
establish dynamic pressure to separate the shaft and the bearing sleeve
in radial direction when the shaft rotates.