According to one embodiment, a magnetic disk includes a disk, first and second heads which write data to the disk and read data from the disk, a first actuator includes the first head, a second actuator includes the second head, first and second controllers which control the first head, the second head, the first actuator and the second actuator, an auxiliary power supply which supplies power when power from a power supply is shut off, and a power supply detection unit which makes power supplied from the auxiliary power supply to the first controller higher than the power supplied from the auxiliary power supply to the second controller when shutoff of power from the power supply is detected.

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 plurality of recording media each including a recording layer and an actuator assembly including an actuator block rotatably supported around a rotation shaft, a plurality of arms extending from the actuator block, and suspension assemblies respectively attached to the arms and supporting respective magnetic heads. Of the plurality of arms, at least one arm has vibration characteristics different from those of the other arms.

Each disk drive in an array includes a housing that encloses a motor and at least one magnetic disk. The housing also encloses first and second actuators each with respective first and second heads that independently access the magnetic disk. The first actuator is mapped to a first logical unit and the second actuator is mapped to a second logical unit. A host interface of each disk drive facilitates access to the first and second logical units. A system includes a first storage controller attached to all of the first logical units as a first active server and attached to all of the second logical units as a first passive server. A second storage controller operates redundantly with the first storage controller. The second storage controller is attached to all of the second logical units as a second active server and attached to all of the first logical units as a second passive server.

A disk drive has a recording head slidably coupled to a rail and in magnetic communication with a disk surface. The recording head has an optical power interface and an optical data interface. An optical transceiver is fixably mounted proximate an end of the rail and optically coupled to the optical power interface and/or the optical data interface of the recording head. The coupling between the optical transceiver and the interfaces facilitates writing data to the disk surface and/or reading data from the disk surface via the recording head.

A disk device includes a plurality of magnetic disks, a plurality of magnetic heads, a first actuator assembly having a plurality of arms and a plurality of suspension assemblies for the magnetic heads and supported to be rotatable about a support shaft, a second actuator assembly having a plurality of arms and a plurality of suspension assemblies for the magnetic heads and supported to be rotatable about the support shaft, and a protective member formed from a material different from a material for the arms. The protective member is provided on a tip end portion of at least one of a first arm closest to the second actuator assembly among the of arms in the first actuator assembly and a second arm closest to the first actuator assembly among the arms in the second actuator assembly.

A hard disk drive includes a drive case and a cover plate, the storage media platers and a spindle, the recording heads and actuators, the connection port, the control logic board and one or more voice coil motor, where the actuators are operated via a voice coil motor; wherein the voice coil motor magnets comprise of a pair of composite permanent magnets on both sides of the voice coil, where each piece of composite permanent magnet comprising: a first core magnet M1, a cladding magnet Mc12 and a second core magnet M2; the magnetization direction of M1 and M2 are opposite to each other; the magnetization direction of Mc12 is substantially perpendicular to the magnetization direction of M1 and M2; the ratio of the width of Mc12 to the thickness or the height of Mc12 is 4:1 or less as seen from the back view.

A data storage device includes a stack of data storage disks mounted on a spindle, a first arm and a second arm. The stack comprises a first plurality of upper disks and second plurality of lower disks. The first arm is movably attached to an actuator shaft, the first arm having a first head end that supports a first head, the first arm configured to move along a first portion of the actuator shaft to enable the first head to interact with data storage surfaces of the first plurality of upper disks. The second arm has a second head end that supports a second head, the second arm attached to and configured to move along a second portion of the actuator shaft, independently of the first arm, to enable the second head to interact with data storage surfaces of the second plurality of lower disks.

There is provided a bearing device including: a tubular sleeve; a shaft held inside the sleeve; and a first bearing, a second bearing, a third bearing, and a fourth bearing, rotatably holding the shaft with respect to the sleeve and arranged in this order in an axial direction. An outer circumferential surface of an outer ring of each of the first to fourth bearings is fixed to an inner circumferential surface of the sleeve, a gap is provided between inner circumferential surfaces of inner rings of the second and third bearings and the shaft, and a spring applying a constant pre-load is provided between the inner rings of the second and third bearings.

According to one embodiment, a suspension assembly includes a support plate, a wiring member disposed on the support plate, and a head supported on the support plate through the wiring member. The wiring member includes a distal end portion electrically connected to the head, a connection end portion extending outside the support plate, and a plurality of wirings extending between the distal end portion and the connection end portion. The connection end portion includes an opening with predetermined length and width and thirteen or more connection terminals disposed in the opening and arranged at intervals in a direction of the length. A percentage of an area of the opening occupied by areas of the thirteen or more connection terminals is 40% to 65% inclusive.