According to one embodiment, an actuator assembly includes a head actuator including an actuator block having a first surface, a second surface intersecting the first surface, and a first groove provided on the second surface, and a suspension assembly supporting a magnetic head and a wiring board including a plate arranged on the first surface, a flexible printed circuit board provided on the plate, and an IC chip provided on the flexible printed circuit board, wherein the plate comprises a first engaging portion engaging with the first groove.

A data storage device includes a first actuator and a second actuator rotatable around a common axis. The data storage device further includes a first electrical connector configured to communicate electrical signals to and from the first actuator via a first flexible circuit. The data storage device further includes a second electrical connector separate from but in a stacked arrangement with the first electrical connector. The second electrical connector is configured to communicate electrical signals to and from the second actuator via a second flexible circuit.

According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

According to one embodiment, a disk device includes a first actuator assembly and a second actuator assembly which are respectively supported by a first bearing unit and a second bearing unit to be rotatable about a support shaft. The first bearing unit includes a first sleeve and a ball bearing. The second bearing unit includes a second sleeve and a ball bearing. The first sleeve includes a first end surface opposed to the second sleeve and an annular first step projecting from the first end surface, and the second sleeve includes a second end surface opposed to the first step with a gap and an annular second step projecting from the second end surface. The second step is opposed to the first step and the first end surface with a gap.

An apparatus comprises a plurality of servo controllers and a plurality of motor control circuits. Each of the plurality of motor control circuits has a primary serial interface (SIF) coupled to one of the plurality of servo controllers and at least one secondary SIF coupled to others of the plurality of servo controllers. Each of a plurality of independently controllable actuators is coupled to one of the motor control circuits. Each of the plurality of motor control circuits is configured to generate a compensated control signal using an actuator command received from the primary SIF and an actuator command received from the at least one secondary SIF. Each of the plurality of motor control circuits is configured to control movement of one of the plurality of actuators using the compensated control signal.

An approach to a reduced-head hard disk drive (HDD) involves a load/unload (LUL) ramp subsystem that includes a ramp assembly that includes a rotatable latch link configured for mechanical interaction with a head-stack assembly (HSA) and a LUL ramp coupled with the latch link, configured such that in response to a force applied to the latch link by the HSA, the latch link rotates which disengages a magnetic latch and drives the LUL ramp to rotate into an operational state disengaged from any recording disk of a multiple-disk stack. The subsystem may further include a motor configured to drive rotation of a lead screw to which the ramp assembly is attached, to drive vertical translation of the ramp assembly, thereby providing for loading the vertically-translatable HSA onto and off of each of the disks of the disk stack.

An approach to a reduced-head hard disk drive (HDD) involves an actuator subsystem that includes a ball screw cam assembly wherein the number of starts of a multi-start screw equals the number of balls riding in a corresponding start. A stepper motor may be disposed within the screw, to drive rotation of the screw, which drives translation of an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack. The actuator subsystem may further include a cam locking mechanism for coupling and decoupling the actuator arm with a coil support structure and corresponding voice coil, so that the cam mechanism is able to move under the control of a voice coil motor when input/output operations are performed and is able to move the actuator arm assembly during translation operations.

An approach to a reduced-head hard disk drive (HDD) involves an actuator subsystem that includes a ball screw cam assembly wherein the number of starts of a multi-start screw equals the number of balls riding in a corresponding start. A stepper motor may be disposed within the screw, to drive rotation of the screw, which drives translation of an actuator arm assembly so that a corresponding pair of read-write heads can access different magnetic-recording disks of a multiple-disk stack. The actuator subsystem may further include a cam locking mechanism for coupling and decoupling the actuator arm with a coil support structure and corresponding voice coil, so that the cam mechanism is able to move under the control of a voice coil motor when input/output operations are performed and is able to move the actuator arm assembly during translation operations.

A method for writing data in a disk drive having actuators each controlling arms extending over disk surfaces, including: receiving a write command from a host; receiving from the host data; dividing the data into data blocks; determining: a first surface from the disk surfaces where data is written by a first head of an arm controlled by a first actuator of the actuators; and a second surface from the disk surfaces where data is written by a second head of an arm controlled by a second actuator of the actuators; determining storage blocks of each of the first and the second surface; and writing first data blocks of the divided data blocks to the determined storage blocks of the first surface using the first head while writing second data blocks of the divided data blocks to the determined storage blocks of the second surface using the second head.

A recording surface of a magnetic disk is divided into first and second zones. A first head of a first actuator arm assembly reads from and/or writes to the first zone exclusively. A second head of a second actuator arm assembly reads from and/or writes to the second zone exclusively. The first and second head are capable of simultaneously reading from and writing to the recording surface.