Magnetic read/write head actuator assembly having asymmetric stator

Abstract

An improved magnetic read/write head actuator assembly for use within a storage disk system that reduces average access time. The actuator assembly includes an actuator arm mounted on pivotal hub. A read/write head is supported at a distal end of the actuator arm such that the head is positioned in close proximity to a rotating magnetic storage disk. An actuator motor cooperates with the actuator arm to provide pivotal motion to the actuator arm about a central pivot axis. The actuator motor includes an asymmetric rotor winding connected to the actuator arm at an end opposite the distal end and an asymmetrical stator magnet structure that is statically mounted in close proximity to the asymmetric rotor winding. The actuator motor, further includes a flux conductive member that forms a closed flux path through the rotor winding and the asymmetrical stator magnet structure. The asymmetric geometry of the stator magnet structure generates an increased magnetic field strength and magnetic field density in a region of the magnet structure that comprises a greater portion of magnetic material. Therefore, when the asymmetric rotor winding reacts with the region of the stator magnet that has the greater portion of magnetic material, an increased torque vector force is realized by the asymmetric rotor winding. The increased torque vector force realized by the rotor is transposed to the actuator arm for increasing the pivotal speed of the actuator arm about the central pivot axis during access of outer diameter tracks of a magnetic storage disk.