Abstract: A hydrodynamic bearing assembly comprises a bearing (10) defining a bearing hole (12) therein, a shaft (20) rotatably received in the bearing hole with a bearing clearance formed between a bearing surface of the bearing and an outer surface of the shaft, and a cover (40) attached to a top end of the bearing. The bearing clearance is filled with lubricant. A locking groove (22) is formed in an outer periphery of the shaft. The cover defines a through hole (42) receiving the shaft at the locking groove. Interlocking devices are formed on the cover and the bearing to join the cover and the bearing.

Abstract: 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.

Abstract: 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.

Abstract: A manufacturing tool (20) for forming a dynamic pressure groove (52) in an inner peripheral surface of a bearing sleeve (50) includes a tool shaft (21) for being rotated in a bore of the bearing sleeve while being moved in an axial direction thereof. Protrusions (25) are integrally and circumferentially arranged on an outer periphery of the tool shaft near a leading end (22) thereof. Machining tips (26) are integrally formed on outmost ends of the protrusions for machining the inner peripheral surface of the bearing sleeve to form the dynamic pressure groove therein.