A disk drive unit has a spindle motor for rotating a disk, a magnetic head for
processing data, a actuator for seeking the magnetic head with respect to the disk,
a voice coil motor for moving the actuator, and a base with an opening and a top
cover that seals the opening. A damper is disposed between the voice coil motor
and the top cover. The voice coil motor comprises first and second yokes, which
are placed opposite each other at a predetermined gap, and a permanent magnet disposed
between the first and second yokes. The first and second yokes respectively have
an inner perimeter edge facing the pivot axis, an outer perimeter edge facing the
base, and a pair of side perimeter edges combining the outer and inner perimeter
edges. The damper includes first dampers with a predetermined width along the pair
of side perimeter edges.