Spindle motor

摘要

A spindle motor comprises a fixed journal, a hub for loading disks, a ball bearing for rotatably supporting the hub and an annular member fixed on one of the fixed journal and the hub. The fixed annular member is configured to create to create a small space with the hub or fixed journal which is opposite the one on which the annular member is fixed. When L1 is the dimension of a space between a top surface of a top disk and a surface of a member facing said top surface of said top disk, and L2 is the dimension of a space between a bottom surface of a bottom disk and a surface of a member facing the bottom surface of the bottom disk, the annular member has grooves for generating air flow directed toward the space of longer dimension, one of said dimensions L1 and L2.