CONDUCTIVE BEARING DEVICE, PIVOT ASSEMBLY FOR HARD DISK DRIVE, AND HARD DISK DRIVE

摘要

PROBLEM TO BE SOLVED: To ensure stable conductivity in a conductive bearing device, to facilitate assembly and injection of a conductive magnetic fluid and to make a rotary portion lightweight.;SOLUTION: On a shaft member 2, a spacer 3 is supported in a rotatable manner by a pair of ball bearings 4. In an outer peripheral part of the shaft member 2, a holding groove 9 is formed from a pair of washers 12 and a permanent magnet 13, and a conductive magnetic fluid 10 is held within the holding groove 9 by a magnetic force of the permanent magnet 13. In a spacer 3, an opening 14 is provided oppositely to the holding groove 9, a cover member 15 is attached to the opening 14, and a conductive pin 11 that is fixed onto the cover member 15 is inserted into the conductive magnetic fluid 10 inside of the holding groove 9. Thus, stable conductivity is ensured and the spacer 3 that is a rotary portion can be made lightweight. Further, in the case of assembly, the conductive magnetic fluid 10 can be injected from the outside through the opening 14 into the holding groove 9, thereby facilitating assembly.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2019,JPO&INPIT