A data storage device comprises a lead actuator that actuates a first read-write head over a first disk and a support actuator that actuates a second read-write head over a second disk. A spindle motor rotates the first and second disks. In response to an emergency power off (EPO) event, a processing device retracts and parks the actuators using an internal supply voltage generated from a back electromotive force (BEMF) voltage of the spindle motor, and egresses data from a volatile to a non-volatile semiconductor memory. Egress is throttled before the actuators are retracted and parked when the internal supply voltage falls to or below a first egress throttling threshold voltage. Egress is throttled after the actuators are retracted and parked when the internal supply voltage falls to or below a second egress throttling threshold voltage.

In accordance with an embodiment a method includes: receiving a slow down command to slow down a speed of a voice coil motor (VCM) in a hard disk drive; in response to receiving the slow down command, operating the VCM in a discontinuous mode by switching on and off a current through the VCM with a duty-cycle, wherein operating the VCM in the discontinuous mode reduces the speed of the VCM; sensing the speed of the VCM while operating the VCM in the discontinuous mode; and varying the duty-cycle of the switching on and off the current through the VCM as a function of the sensed speed of the VCM operated in the discontinuous mode, wherein varying the duty-cycle comprises reducing the duty-cycle in response to a reduction of the sensed VCM speed.

A voice coil motor yoke having a magnet bonding surface includes an annular groove inside a bonding region on the magnet bonding surface, the bonding region having substantially the same shape as a contour of a magnet to be bonded on the magnet bonding surface of the yoke. A region surrounded by the annular groove on the magnet bonding surface is an adhesive application region. A voice coil motor includes: a pair of the voice coil motor yokes; an adhesive applied to the adhesive application region of each of the pair of yokes; and a pair of rare earth magnets bonded via the adhesive to the bonding region of each of the pair of yokes.

An approach to a reduced-head hard disk drive (HDD) involves an actuator elevator subsystem that includes a ball screw cam assembly with an axial flux permanent magnet (AFPM) motor affixed to a cam 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.

According to one embodiment, a disk device includes a base, a drive motor, disk-shaped magnetic recording media, a carriage supporting a magnetic head to be movable with respect to the magnetic recording medium, and a plurality of fixing members. The base includes a bottom wall and a side wall having a first corner and a second corner. The fixing member includes a support post erected on the bottom wall, and extending parts each extending from the support post between the magnetic recording media. The fixing members include a first fixing member provided between the magnetic recording medium and the first corner, a second fixing member provided between the magnetic recording medium and the second corner, and a third fixing member provided on a side facing the first fixing member.

A data storage device is disclosed comprising a plurality of disks each comprising a top disk surface and a bottom disk surface, and a plurality of actuator arms each comprising a first fine actuator configured to actuate a top head over one of the top disk surfaces and a second fine actuator configured to actuate a bottom head over one of the bottom disk surfaces. A first fine driver controls the fine actuators of an even interleave of the actuator arms, and a second fine driver controls the fine actuators of an odd interleave of the actuator arms.

Systems and methods are disclosed for resource allocation for multi-actuator systems. In some examples, a data storage device can include two or more independently moveable voice coil motor (VCM) actuators where the resources of the system to operate the VCM actuators are divided. The disclosure here describes methods to allocate or re-allocate the divided resources, such as unused resources, to a VCM actuator that has a need for more resources. The methods and systems herein can also be applied to other actuator systems.

A data storage device is disclosed comprising a first plurality of heads actuated over a first subset of disk surfaces by a first actuator, and a second plurality of heads actuated over a second subset of disk surfaces by a second actuator. A plurality of access commands is received, wherein each access command is associated with one of the heads. A scalar is configured for each access command based on at least one of a current radial location of the corresponding head or a target radial location of the corresponding head associated with executing the access command. The access commands are sorted based on the scalars, and one of the access commands is selected for execution based on the sort.

A data storage device comprises a lead actuator that actuates a first read-write head over a first disk and a support actuator that actuates a second read-write head over a second disk. A spindle motor rotates the first and second disks. In response to an emergency power off (EPO) event, a processing device retracts and parks the actuators using an internal supply voltage generated from a back electromotive force (BEMF) voltage of the spindle motor, and egresses data from a volatile to a non-volatile semiconductor memory. Egress is throttled before the actuators are retracted and parked when the internal supply voltage falls to or below a first egress throttling threshold voltage. Egress is throttled after the actuators are retracted and parked when the internal supply voltage falls to or below a second egress throttling threshold voltage.

A data storage device is disclosed comprising a first head connected to a distal end of a first actuator arm, a second head connected to a distal end of second first actuator arm, a first coupler configured to couple the first actuator arm to an actuator, and a second coupler configured to couple the second actuator arm to the actuator. Access commands stored in a command queue are sorted into an execution order based on a selective coupling of the first and second actuator arms to the actuator. At least one of the access commands is executed based on the execution order in order to access at least one of a first and second disk surfaces using at least one of the first and second heads.