BEARING STRUCTURE, SPINDLE MOTOR, AND HARD DISK DRIVE

摘要

A bearing structure in which static electricity accumulated in a rotation-side member rotatable in a noncontact way is safely discharged to a fixed-side member, and an HDD free from a failure due to static electricity are disclosed. The bearing structure has an electrical connection mechanism including, for example, a magnetic fluid (13) for electrically connecting a fixed-side member to a rotation-side member disposed on the rotary shaft of the rotation-side member rotatable in a noncontact way or near the rotary shaft. The rotary shaft and the space near the rotary shaft are almost free from the influence of the relative rotation between the fixed-side member and the rotation-side member and the influence of the air current for producing dynamic pressure. Therefore the position where the magnetic fluid (13) is disposed is stabilized and maintained, and the static electricity of the rotation-side member is completely discharged to the fixed-side member. Problems such as viscous resistance and heat generation hardly arise. Instead of use of magnetic fluid, an electrical connection mechanism such as a flexible tongue piece of a conductor can be used. The HDD includes a dummy disk and a dummy head so as to induce electric discharge between them, thereby preventing an electrostatic failure of the other parts of the HDD.