Patent ID: 7561377

Claim:
A magnetic disk drive comprising: a motor hub including a disk support portion and a flange portion, said disk support portion supporting a magnetic disk thereon, said flange portion being located higher than said disk support portion and protruding radially outward with respect to a rotational center of said magnetic disk; a clamp having a ring shape and including an inclined undersurface inclined downward from the outer circumference of said ring shape toward the inner circumference of said ring shape, said ring shape encircling said flange portion, said clamp being engaged around the outer circumference of said flange portion; and an O-ring engaged with said inclined undersurface of said clamp so as to press said clamp against said flange portion or clamp said clamp, said O-ring being further engaged with said magnetic disk so as to press said magnetic disk against said disk support portion, wherein: said clamp includes a stopper extending downward; and the distance between said magnetic disk and said stopper is smaller than the distance between said magnetic disk and an arm which supports a magnetic head in such a way that said magnetic head flies over said magnetic disk.