Rotary disk drive actuator

Abstract

An actuator assembly for a disk drive is presented which includes a voice coil motor having a top return plate which is held in place substantially only by the magnetic field of the voice coil motor magnet, and no extra screws or other fasteners are needed. Non-magnetic spacers position the top return plate above the voice coil motor magnet. Consequently, there are no magnetic portions to interfere with the desired return path of the magnetic field. The actuator assembly includes a preloaded crash stop which provides an elastic as well as a dampening resistive force in stopping a positioner arm assembly upon a crash. Additionally, the crash stop is comprised substantially of non-magnetic material so as to avoid interfering with desired magnetic return paths required for the operation of the actuator. Furthermore, the crash stop comprises an integral magnetic latch which holds the positioner arm assembly in a fixed location when the disk drive is not operating. The magnetic latch provides 'line contact,' rather than 'surface contact,' between the positioner arm and the magnetic poles of the latch, thus allowing for greater margin of error in positioning and assembling the components of the latch and positioner arm.