Abstract: Disk drives including suspensions and head gimbal assemblies in which the load beam pitch angle is reduced exhibit a reduced disk flutter induced track mis-registration (TMR) at the disk outer diameter. The reduction in the load beam pitch angle may be achieved through variations in the load beam, hinge and/or mount plate configurations, relative positions and/or thickness.

Abstract: An actuator arm assembly for a disk drive includes first and second stamped actuator arms including first and second arm portions, first and second body portions defining first and second body surfaces, and first and second coil-supporting arm portions defining first and second pairs of coil supporting arms for supporting a coil portion of a voice coil motor. When the first and second stamped actuator arms are attached to one another, the first pair of coil supporting arms faces and is in contact with the second pair of coil supporting arms to define first and second coil attachment surfaces, and the first body surface faces and is in contact with the second body surface to define a third coil attachment surface.

Abstract: A chassis for receiving a plurality of disk drives includes a plurality of disk drive receiving stations. Each station is configured to carry out testing and/or servo writing operations on a received disk drive. Each station includes a base, a nest assembly and a plurality of elastomeric mounts that elastically couple the nest assembly to the base to enable movement of the nest assembly relative to the base. The nest assembly includes a nest configured to receive and mate with the disk drive and a printed circuit board. Each station includes a separate vibration isolating mass that is coupled to the nest. The vibration isolating mass at least partially isolates vibrations originating within the nest from being transmitted through the elastomeric mounts to other nests in the chassis and at least partially isolates vibrations originating outside the nest from being transmitted through the elastomeric mounts to the nest assembly.

Abstract: A disk drive includes a pivot-bearing cartridge configured to pivotally support the head stack assembly on the base of the drive. A tolerance ring is coupled to the pivot-bearing cartridge and includes a single sleeve defining an inner sleeve surface facing the pivot-bearing cartridge and an outer sleeve surface facing away therefrom, and a layer of dampening material disposed on the inner or outer sleeve surfaces so as to be in contact with the pivot-bearing cartridge or the bore surface of the through bore that is defined in the body portion of the head stack assembly, respectively.

Abstract: A disk drive includes a disk and a head stack assembly for reading and writing to the disk. The head stack assembly includes a body portion, a first actuator arm cantilevered from the body portion and a second actuator arm cantilevered from the body portion. A coil portion is cantilevered from the body portion in an opposite direction from the first and second actuator arms. An actuator arm spacer is disposed between the first and second actuator arms and away from the body portion, and mechanically links the first and second actuator arms.

Abstract: A disk drive has a spindle motor, a disk mounted for rotation on the spindle motor, and a head for reading from and writing to the disk. The disk includes a recording surface having a track that includes a first full servo wedge and a second full servo wedge, each of the first full and second full servo wedges defining a leading end and a trailing end and having, between leading and trailing ends, a preamble, a servo sync word, a track ID, and a plurality of servo positioning burst fields. The recording surface further includes user addressable data locations and a first partial servo wedge disposed between the trailing end of the first full servo wedge and the leading end of the second full servo wedge. The first partial servo wedge is devoid of preamble, track ID and wedge ID and includes a short servo sync mark that is different from the servo sync word. The servo sync mark defines a predetermined bit pattern that is immediately followed by a plurality of servo bursts.

Abstract: A disk drive has a sampled servo system controller and a disk. The disk has a plurality a plurality servo burst fields, each including a first normal burst field, a first quadrature burst field, a second normal burst fields and a second quadrature burst field. A portion of the first quadrature burst field is circumferentially contiguous with the first normal burst field and spans a portion of a radial extent of the first normal burst field. The second normal burst field is radially aligned with and away from the first normal burst field and spans a portion of a radial extent of the first quadrature burst field. The second quadrature burst field is radially aligned with and away from the first quadrature burst field and spans a portion of a radial extent of the second normal burst field.

Abstract: A disk drive has a sampled servo system controller and a disk. The disk has a plurality a plurality servo burst fields, the plurality of servo burst field including first and second normal burst fields, and first and second quadrature burst fields. A portion of the first quadrature burst field is circumferentially contiguous with the first normal burst field and spans a portion of a radial extent of the first normal burst field. The second normal burst field is radially aligned with and away from the first normal burst field and spans a portion of a radial extent of the first quadrature burst field. The second quadrature burst field is radially aligned with and away from the first quadrature burst field and spans a portion of a radial extent of the second normal burst field. The first normal burst field and the first quadrature burst field have a same first phase and the second normal burst field and the first quadrature burst field have a same second phase. The first phase is different than the second phase.

Abstract: An arm assembly of an actuator arm assembly of a disk drive is stamped from a single flat sheet of material and includes first and second actuator arm portions and one or more bendable portions integrally joining the first and second actuator arm portions. A method of making an arm assembly for a disk drive includes steps of providing a flat sheet of material and stamping an arm assembly from the sheet such that the stamped arm assembly includes first and second actuator arm portions and one or more bendable portions integrally joining the first and second actuator arm portions.

Abstract: A disk drive has a sampled servo system controller and a disk. The disk has a plurality a plurality servo burst fields, the plurality of servo burst field including first and second normal burst fields, and first and second quadrature burst fields. A portion of the first quadrature burst field is circumferentially contiguous with the first normal burst field and spans a portion of a radial extent of the first normal burst field. The second normal burst field is radially aligned with and away from the first normal burst field and spans a portion of a radial extent of the first quadrature burst field. The second quadrature burst field is radially aligned with and away from the first quadrature burst field and spans a portion of a radial extent of the second normal burst field. The first normal burst field and the first quadrature burst field have a same first phase and the second normal burst field and the first quadrature burst field have a same second phase. The first phase is different than the second phase.

Abstract: Disclosed herein are disk drives and mobile host devices that include a resetable shock sensor. A mobile host device may include a memory device configured to receive a shock event signal and a shock sensor. The shock sensor may be coupled to the memory device and is configured to generate the shock event signal. The shock sensor includes a fixed portion, and a movable portion responsive to shock events. The movable portion is configured to remain out of contact with the fixed portion until the mobile host device is subjected to a shock event greater than a predetermined magnitude and to contact and remain in contact with the fixed portion and to generate the shock event signal after the mobile host device is subjected to a shock event greater than the predetermined magnitude.

Abstract: Disclosed herein are disk drive spindle motors and disk drives using same that include one of more structures that function as travel limit stops that are designed to transfer the load created by a shock impulse to non-essential mechanical features and bypass the bearing structures, thereby keeping the load imposed thereon by the shock impulse below damaging levels. The spindle motor may also include one or more compliant members between the bearing structures and facing surfaces. Such compliant members may be combined with pre-load keepers that preload the bearings by axially compressing the compliant members.

Abstract: A disk drive, includes a disk and a head stack assembly for reading and writing to the disk. The head stack assembly includes a body portion defining a through bore that defines a pivot axis; an actuator arm cantilevered from the body portion, the actuator arm defining a thickness, the actuator arm defining at least one through slot in the thickness thereof through which air can flow, each through slot defining a slot surface that is generally perpendicular to the pivot axis; a coil portion cantilevered from the body portion in an opposite direction from the actuator arm, and a head gimbal assembly coupled to the actuator arm.

Abstract: A disk drive includes a disk, a latch assembly including a magnet and a head stack assembly for reading and writing to the disk. The head stack assembly includes a body portion defining a through bore that defines a pivot axis; an actuator arm cantilevered from the body portion; a head gimbal assembly coupled to the actuator arm; a coil portion cantilevered from the body portion in an opposite direction from the actuator arm, the coil portion defining first and second actuator fork members, one of the first and second actuator fork members defining a tang-supporting surface, the tang-supporting surface defining at least one cleating feature configured to increase a surface area of the tang-supporting surface, and a tang configured to interact with the magnet, the tang being attached to the tang-supporting surface by a layer of adhesive disposed on the tang-supporting surface.

Abstract: A disk drive has an enclosure that includes a first portion and a second portion that is configured to mate with the first portion. A spindle motor is attached to the first portion and a disk is mounted to the spindle motor. A head stack assembly is pivotally coupled to the second portion prior to the first and second portions being mated to one another. The head stack assembly includes a read write head that is configured to read from and write to the recording surface of the disk after the first and second portions are mated to one another.

Abstract: A disk drive selectively provides either higher-performance seek operations or reduced-audible noise while effecting seek operations. A higher performance seek operating mode and a quiet seek operating mode are defined. The servo controller controls seek operations and may store and/or access a number of seek profiles including a first seek profile defined to provide relatively short average seek times and a second seek profile defined to provide quieter operation on average in comparison with the first seek profile. The servo controller and associated circuitry causes the drive to effect a seek operation subject to the first seek profile in response to the higher performance seek operating mode and effect a seek subject to the second seek profile in response to the quiet seek operating mode.

Abstract: The base of a disk drive defines an interior shroud surface. The interior shroud surface is configured to follow a portion of the curvature of the disk at a distance from the outer diameter of the disk. The interior shroud surface of the base may define one or more channels for modifying the airflow developed as the disk rotates. The interior shroud surface defines an opening to enable the head stack assembly to pivot over the disk, which opening is bounded by a leading shroud portion and a trailing shroud portion. The leading shroud portion and/or the trailing shroud portion may also define a channel or channels for modifying the airflow that is developed as the disk rotates.

Abstract: A disk drive and methods for preventing a coil in a voice coil motor from overheating due to the application of excess current. The disk drive comprises a servo control system. The servo control system is adapted for applying a current to a coil of the voice coil motor thereby causing the voice coil motor to move the head according to a seek distance. The servo control system generates a plurality of seek profiles for each of a plurality of seek distances and a plurality of current limits for the plurality of seek profiles. Each of the plurality of seek profiles defines a plan for controlling the current to be applied to the coil while the voice coil motor is operated over the seek distance. The plurality of current limits each define a maximum current allowed while controlling the current to be applied to the coil.

Abstract: A disk drive includes a voice coil motor (VCM) having a narrow coil angle and a magnet magnetized with two or three pole pairs. The VCM magnet may define first, second and third sections, the second section being magnetically polarized in an axial direction that is opposite to that of the first and third sections. The first radial leg of the VCM coil faces the second section and the second radial leg faces the third section when the head is positioned at a non-operational position. The first radial leg faces the first section and the second radial leg faces the second section when the head is reading and/or writing to the data portion of the disk. Alternatively, the VCM magnet defines first and second sections that are magnetized in opposite axial directions.

Abstract: A disk drive includes a disk drive base and a disk stack, the disk stack comprising a first disk including a first recording surface and a second recording surface. A spindle motor attached to the disk drive base rotates the disk stack about a spindle motor rotation axis. A ramp load engages at least the first and second lift tab of a head stack assembly. The ramp load includes a shaft coupled to the disk drive base, the shaft defining a shaft axis that is parallel to the spindle motor rotation axis. The ramp load also includes a first ramp defining a first lift tab engaging surface for engaging the first lift tab and a first facing surface configured to face the first recording surface of the first disk at a first distance, and a second ramp defining a second lift tab engaging surface for engaging the second lift tab and a second facing surface configured to face the second recording surface of the first disk at a second distance.