Quantum Corporation

Western Digital Technologies, Inc.

Seagate Technology Incorporated

Thomas A Tacklind

William G Moon

Robert P Ryan

Stephen Paul Williams

Lakshman Rathnam

Dean V Dang

Thomas R Stone

Ashok K Desai

Bruce R Peterson

Albert L Hartman

Ronald R Moon

Clifford M Gold

Michael G Machado

Michael K Liebman

Steven Nemshick

Antony Nguyen

Daniel E Barnard

James H Do

Louis G Pace

Amir Norton

Robert A Caldeira

August L Klerks

Timothy Boyle

Robert O Campbell

Gokhan Orakcilar

Lou Pace

A disk drive includes a spindle motor attached to a disk drive base. The spindle motor includes a hub that rotates about a spindle rotation axis. An annular disk is mounted on the hub. A clamp contacts a top surface of the hub. The clamp includes first and second pluralities of openings therethrough. The clamp is attached to the hub by a plurality of fasteners, each of the plurality of fasteners passing through one of the first plurality of openings. Each of the second plurality of openings has a closed outer periphery within the clamp. Each of the first plurality of openings is disposed directly between the spindle rotation axis and a corresponding one of the second plurality of openings.

Disk drive having a disk clamp with openings directly radially outboard of fasteners

A method to assemble a disk drive having a spindle that includes a hub. At least one disk is placed on the hub. A clamp is fastened to the hub by a plurality of threaded fasteners. Each of the plurality of threaded fasteners is initially tightened. After initial tightening, an initial couple imbalance of the spindle is determined. After the initial couple imbalance is determined, a first selected threaded fastener of the plurality of threaded fasteners is selected and rotated by a first amount of rotation that is significantly different from a second amount of rotation of a second selected threaded fastener of the plurality of threaded fasteners. The selection and rotation of the first selected threaded fastener of the plurality of fasteners is determined based on the initial couple imbalance of the spindle.

Method to assemble a disk drive

A dual stage, head stack assembly () for a disk drive () having a storage disk () is provided herein. The head stack assembly () includes an actuator arm (), a coarse positioner (), a transducer assembly (), a base plate () and a fine positioner (). The coarse positioner () moves the actuator arm (). The transducer assembly () includes a load beam (), a flexure () and a data transducer (). The base plate () includes at least one positioner cavity () which receives the fine positioner (). A control system () directs current to the coarse positioner () to move the actuator arm () to position the data transducer () at or near a target track () on a storage disk (). The control system () also directs current to the fine positioner () to precisely position and maintain the data transducer on the target track (). Because the fine positioner () independently moves only the transducer assembly (), a higher system band-width is achieved.

Dual stage, head stack assembly for a disk drive

A disk drive is disclosed comprising a disk and a voice coil motor (VCM) for rotating an actuator arm about a pivot in order to actuate a head over the disk. During a park operation, a latching characteristic associated with latching the actuator arm is measured and used to configure a latching parameter that reduces acoustic noise. The latching parameter is used to latch the actuator arm by seeking the head to a latching track, maintaining the head over the latching track for a predetermined interval, applying an acceleration pulse to the VCM for an acceleration pulse period, applying a braking pulse to the VCM for a brake pulse period, and applying a latching current to the VCM.

Disk drive employing a calibrated brake pulse to reduce acoustic noise when latching an actuator arm

An airlock latch assembly for restraining a disk drive actuator when the disk drive is subjected to rotary shock forces includes a first member and a second member rotatably mounted to the disk drive base. The second member engages the first member, preventing the first member from disengaging with the actuator assembly while the disk is not spinning. The two members are mechanically related such that one member can rotate in one direction only when the other member rotates in the opposite direction. The latch assembly also restrains the actuator in its proper position when the disk drive is subject to linear shock forces.

Air actuated latching mechanism rotationally resistant to rotational

An improved actuator apparatus is employed in a hard disk drive device for positioning read/write heads over tracks on a data storage disk of the disk drive. The actuator apparatus includes an all plastic C-block assembly providing the actuator apparatus with a reduced weight, lower inertia and better damping characteristic which enable improved dynamic performance. The C-block assembly includes a body portion and a pair of tapered support arms extending from the body portion in a parallel orientation. The support arms each have a suspension for a read/write head staked thereto within a mounting surface aperture at a distal end of the arm. The mounting surface aperture is configured to have a non-circular shape to facilitate staking of the read/write head to the support arm and enable construction of the C-block assembly out of plastic. The non-circular shape of the mounting surface aperture additionally enables swaging within the aperture of the plastic support without causing the plastic support arm to break or crack.

Actuator apparatus with plastic C-block

A low friction bearing is provided for a mass balanced rotary voice coil actuator of a disk drive including a base. The bearing comprises an upper pivot bearing assembly fixed to one of the actuator and the base and including a plurality of small bearing balls in an outer bearing race thereof, a lower pivot bearing assembly fixed to the same one of the actuator and the base and including a plurality of small bearing balls in an outer bearing race thereof, an upper main bearing ball for engaging the other of the actuator and the base and for making rolling contact against the plurality of small bearing balls of the upper pivot bearing assembly, and a lower main bearing ball for engaging the same other of the actuator and the base and for making rolling contact against the plurality of small bearing balls of the lower pivot bearing assembly.

Ball spindle for reduced friction rotary actuator in disk drive

A low cost, polyphase spindle motor for a hard disk drive comprises a base, a cup-shaped rotating hub for mounting at least one rotating data storage disk, a bearing assembly mounted between the base and the hub enabling rotation of the hub relative to the base, and a cylindrical permanent magnet mounted to an inside cylindrical wall of the hub and defining a plurality of circumferentially alternating magnetic poles. A single ferromagnetic sleeve is mounted to the base and forms one element of the bearing assembly. The sleeve defines a plurality of generally U-shaped stator armature assemblies fixed with respect to the base, each stator armature assembly comprising a top stator disk of ferromagnetic material, a bottom stator disk of ferromagnetic material and a cylindrical portion of the ferromagnetic sleeve magnetically coupling the top disk portion and the bottom disk portion, the stator armature further including a coil between the top stator disk and the bottom stator disk, each stator disk defining a plurality of circumferentially spaced apart stator pole ends being in number related to the number of poles of the permanent magnet, the pole ends of the bottom stator disk being angularly displaced from the pole ends of the top stator disk by a predetermined first electrical angle, the pole ends of the stator disks of each of the plurality of armature assemblies being electrically angularly displaced from the pole ends of at least one of the stator disks of the other of the plurality of armature assemblies by a predetermined second electrical angle.

Low cost permanent magnet disk spindle motor

A magnetic latch for a disk file actuator comprises a latch plate formed of a magnetic material of low magnetic hardness located on the actuator; a core ferromagnetic material of medium magnetic hardness mounted relative to the base and surrounded by a coil. A power supply is selectively coupled to the coil for applying magnetizing/demagnetizing energy to the core. As the latch plate moves in a direction toward the core and a magnetizing force is applied by the power supply, the latch plate becomes drawn to and restrained by the core. When a demagnetizing force is applied to the coil by the power supply, the actuator is released from the latched position.

Active electromagentic latch having no moving parts for disk file

A miniature fixed disk drive data storage and retrieval subsystem manifesting reduced acoustical noise during data storage and retrieval operations includes a flat, generally rectangular box-shaped base defining a substantially continuous bottom wall and a continuous peripheral sidewall ending in a continuous peripheral lip region. The base defines an interior chamber in which a mass balanced rotary actuator head positioner structure and an in-hub spindle motor assembly are positioned for rotating at least one data storage disk. A mechanical reinforcement structure is secured between an upper region of the rotary actuator structure and the base, and between an upper region of the spindle motor assembly and the base. A cover encloses the interior chamber and is secured at the continuous peripheral lip region by a mechanical isolation and sound dampening. The cover is also mechanically isolated from the mechanical reinforcement structure by a continuous airspace therebetween. With this arrangement acoustic noise otherwise emanating away from the cover is attenuated.

Disk drive with reduced acoustic noise

A miniature disk drive achieves storage densities of at least approximately 1700 tracks per inch per storage surface of a storage disk defining a series of radially extensive servo sectors embedded within circumferential zones of data tracks. The sectors are recorded at a constant data transfer rate while each zone has a data transfer rate adapted to disk radius. The drive includes a head and head positioner, a read preamplifier for amplifying analog signals read from, and for amplifying signals to be written to, a storage surface. A circuit board carries drive electronics including a read channel, a servo processing circuit for recovering head location information from the servo sectors, a data block sequencer for sequencing data blocks between a buffer and the storage surface, a buffer memory controller for controlling the buffer, a bus level interface circuit for transferring data blocks between the buffer and a host computer, and a programmed digital controller which functions within a head position servo loop and which also controls the sequencer, buffer controller and bus level interface circuit. As one feature, the servo sectors split data blocks into segments. Segment byte counts in each data block header are used by the sequencer automatically to assemble the segments into data blocks during read and to divide the blocks into segments during write. A single VLSI circuit including the sequencer, servo processing circuit, memory controller and an interface to the microcontroller is disclosed.

High capacity submicro-winchester fixed disk drive

Apparatus providing improved RFI/EMI shielding includes a base of conductive material, such as cast or forged aluminum alloy, the base defining a substantially continuous floor and integrally formed base sidewalls extending upwardly from the floor along the periphery thereof. The base sidewalls define an inset-stepped region above an upper outer peripheral ledge extending around the periphery of the base sidewalls. A plurality of closely spaced apart, knife-blade protrusions formed along the edge extend upwardly from the ledge and angle inwardly toward the base sidewalls within the inset-stepped region. A cover, substantially congruent with the base defines a ceiling and integral cover sidewalls extending downwardly to fit closely over the inset-stepped region so as to come into engagement with the knife-blade protrusions. A clamping arrangement, such as plural spaced apart screws passing through peripheral openings of the cover and entering threaded bores in the base for example, cause the cover securely to clamp down over the base such that facing portions of the cover are deformed over the knife-blade protrusions of the base, thereby establishing very low impedance, closely spaced apart contacts along the gap between the cover and base, for grounding out RFI/EMI.

Growing community of inventors

San Martin, CA, United States of America

Thomas A Tacklind