A hard disk drive has a motor mounting bracket with mounting screws that attach
from outside the drive and external to the seal with a screw bolt pattern diameter
that is larger than an outer diameter of the motor hub. This configuration greatly
reduces contamination inside the disk drive since all contaminants due to the screws
are sealed from entering the disk drive. Consequently, the bottom of the mounting
bracket is extended to the form factor limit to increase the internal space that
is provided for the stator/winding of the motor. In relatively high platter count
disk drives, the bottom disk is positioned very close to the motor bracket with
this approach, which normally would cause the air drag to increase drastically
and thereby impede the performance of the disk drive. Bosses may be used on the
bracket to accommodate blind tap hole depths from the external surface of the bracket.