System and method of constraining vibration in a disk drive unit and motor device

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.