DD motor in magnetic disk drive

摘要

A DD motor in a magnetic disk drive is disclosed. The DD motor comprising a sheet of metal plate formed in a two-stage disk-shaped, which includes an upper stage portion having an opening at the center thereof and a lower stage portion provided continued from the upper stage portion, a spindle shaft served as a central axis of the DD motor and inserted into the opening of the upper stage portion, and a resin portion formed integrally on a top face and a back face of the upper stage portion, in which magnetic material powder is mixed, wherein the resin portion connects the spindle shaft and the metal plate uniformly. Central axes of the small diameter disk-shaped upper stage portion and the large diameter disk-shaped lower stage portion are located coaxially. A peripheral edge of the upper stage portion is bent downwards to form a rim.