Spindle grounding device using magnetic fluid

摘要

The hub includes a cup attached to the hub or rotating portion of the disk drive. The cup has a top. Both the cup and top have openings therein which accommodate the fixed shaft. The cup is filled with ferrofluid. The portion of the shaft passing through the cup and top is magnetized so magnetic seals are formed at the openings. Electrical charge is transmitted to the shaft via the cup and the ferrofluid. A similar arrangement is shown for a disk drive having a rotating shaft in which the cup is incorporated into the hub and a magnetized pin attached to the housing is inserted into the cup.