FLUID DYNAMIC BEARING DEVICE AND MOTOR PROVIDED THEREWITH

摘要

Provided is a fluid dynamic bearing device (1), including: a bearing sleeve (8) made of sintered metal; a rotary member (2) including a shaft portion (21) inserted along an inner periphery of the bearing sleeve (8) and a hub portion (23) expanding radially outward from one end of the shaft portion (21) ; and first and second thrust bearing portions (T1, T2) that form thrust bearing gaps respectively on an upper end surface (8b) and a lower end surface (8c) of the bearing sleeve (8) along with rotation of the rotary member (2). At least an outer peripheral surface of the bearing sleeve (8) is subjected to pore sealing treatment. A sealing gap (S) for retaining an oil surface of lubricating oil is made along a tapered outer peripheral surface (8d1) of the bearing sleeve (8). A lid member (10) having a bottomed cylindrical shape being fixed to an outer periphery of a lower end of the bearing sleeve (8).