Disk drive employing a voice coil motor comprising a yoke for generating a undirectional magnetic flux and a voice coil partially interacting with the undirectional magnetic flux

摘要

A disk drive is disclosed including a disk, an actuator arm including a head, and a voice coil motor for actuating the actuator arm to position the head radially over the disk. The voice coil motor includes a voice coil portion including a first side and a second side opposite the first side for conducting a current. The current conducted by the first side generates a first side magnetic flux in a first direction, and the current conducted by the second side generates a second side magnetic flux in a second direction different from the first direction. The voice coil motor further includes a rotary voice coil yoke including a first magnet for generating a unidirectional magnetic flux, and a magnetic flux conductor shaped to form an air gap with respect to the first magnet, the magnetic flux conductor for guiding the unidirectional magnetic flux through the air gap. The first side of the voice coil portion is located substantially within the air gap such that the first side magnetic flux substantially interacts with the unidirectional magnetic flux, and the second side of the voice coil portion is located substantially outside the air gap such that the second side magnetic flux does not substantially interact with any magnetic flux.