Hard disk drive having a disk fluttering reducing unit

摘要

A hard disk drive having a disk fluttering reducing unit includes a lower air damper forming member provided on an upper surface of the base plate to face a bottom surface of an outer circumferential side of the disk, and an upper air damper forming member provided on a bottom surface of the cover plate to face an upper surface of an outer circumferential side of the disk. At least one air compression surface inclined in a circumferential direction of the disk so that a gap with the disk decreases along a rotational direction of the disk is formed at each of the surfaces of the air damper forming members facing the disk. The air compression surface can be inclined in a radial direction of the disk so that a gap with the disk decreases from an inner circumferential side to an outer circumferential side. When at least two disks are provided, a middle air damper forming member can be interposed between the two disks is provided. Thus, disk fluttering is reduced by an air damping operation of the disk fluttering reducing unit so that reliability of data recording and reproducing is improved. IMAGE