International Business Machines Corporation

Other

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Storage Technologies

Kiyoshi Satoh

Arun Sharma

Sri Muthuthamby Sri-Jayantha

Hien Phu Dang

Shingo Tsuda

Vijayeshwar Das Khanna

Gerard McVicker

Tetsuo Ueda

Naoyuki Kagami

Hiroyasu Tsuchida

David W Albrecht

Isao Yoneda

Hiroki Kitahori

Hideki Ohzeki

Nobuyuki Kitazaki

Yuzo Nakagawa

Tatsuo Nakamoto

Masakazu Sasaki

Eiji Soga

Sunao Nemoto

S M Sri-Jayantha

Kiochi Takeuchi

Nayouki Kagami

Tadahiro Ohmi

Toshiki Hirano

Fu-Ying Huang

Akihiko Aoyagi

Yoshio Uematsu

Hiroyuki Ono

Gregory Michael Frees

Toshiaki Wada

Sachiyo Baba

Shinichi Matsuzaki

Yoshimi Masuda

Koichi Takeuchi

Akihiro Ohyama

Tetsuo Senba

Hiroshi Mihira

Jerry T Coffey

Yasuhiko Kato

Takeshi Chawanya

Tsuyoshi Nagata

Kosuke Tamaru

Singo Tsuda

A system for mounting a hard disk enclosure (HDE), includes a casing pivotably mounted to minimize at least one of settle-out dynamics, external rotational vibration, and emitted vibration, the casing allowing the HDE to rotate substantially freely, wherein the center of gravity of the HDE is substantially the same as a pivot point of the casing. Further, a computer chassis includes a housing, at least one disk drive assembly for being housed by the housing, and a plurality of theta-mounts integrally built within the housing.

Mounting system for disk drive having a rotary actuator

A base plate of a stainless-steel body material formed by pressing is polished and cleared of burrs by means of an abrasive material that consists mainly of Fe O in a polishing process. The polished base plate is heated to a heat treatment temperature for solid solution in a reducing atmosphere in a heat treatment process. In this heat treatment process, an oxide in the constituents of minute fragments of the abrasive material in the surface of the body material of the base plate is reduced to leave iron, which is dispersed into the body material.

Iron component and a manufacturing method therefor

Rotationally free mount system for disk drive having a rotary actuator

In order to provide a suspension, a head suspension assembly, and a disk drive apparatus that can contribute to an increase of record and playback reliability, holes in ribs of the head suspension assembly are provided. This design decreases the displacement of a head slider that is caused by Karman vortex streets occurring near the ribs in company with the rotation of the magnetic disk

Suspension, head suspension assembly, and disk drive apparatus

To provide a piezoelectric sensor that never sacrifices work properties such as when a lead wire is to be soldered to one of a pair of electrodes of a piezoelectric sensor, and the other electrode is to be bonded and fixed to a predetermined member with an adhesive, and to bond the ground electrode of the piezoelectric sensor to the conductive portion of the object member with an adhesive so as to be fixed and connected electrically, thereby preventing a short-circuit that might occur between the two electrodes due to extruded and stuck adhesive, and to provide an easier method for testing whether or not the ground electrode is connected electrically to the conductive portion of the object member. A piezoelectric sensor has two electrodes that are formed with different materials appropriate for soldering and bonding by an adhesive. The ground electrode of the piezoelectric sensor is bonded to the object member with a non-conductive adhesive so as to be connected electrically. Furthermore, the capacity between the output electrode of the piezoelectric sensor and the object member is measured to check the electrical connection between the ground electrode and the object member.

Apparatus and method for fixing and checking connections of piezoelectric sensor, actuator, and disk unit

A motor having reduced deformation due to a temperature change. The motor is an outer ring type motor having a bearing cartridge, which integrates the shaft, ball bearings and sleeve. The outer periphery of the sleeve is attached to the inner periphery of the hub at a bonding region positioned axially between the ball bearing holding portions. The bonding portion includes a stress reducing region. The diameter of the hub within the stress reducing region is not uniform in order to reduce the stress generated between the outer periphery of the sleeve and the inner periphery of the hub due to thermal expansion.

Spindle motor-having improved bonding between its bearing cartridge and hub

In order to handle platter flutter in a hard disk operated at high speed (e.g. 10,000 RPM) and maintain tracking of read/write head, peak filters are added to a head tracking servo feedback loop. In some embodiments, several lag-lead type peak filters centered at a plurality of flutter mode frequencies are provided to process a Position Error Signal (PES) read from the read/write head. The several filter are preferably arranged in series (i.e. to operate on the PES sequentially), alternatively the filters can be arranged in parallel. Phase lags and leads caused by the several filters partially cancel at frequencies intermediate center frequencies of the several filters. According to another embodiment two or more, preferably three narrow band filters are used to cover the spectrum of each flutter mode. In a configuration mode, a spectrum of the flutter modes can be obtained and used to set the center frequencies, and bandwidths of filters used to filter out the flutter modes.

Servo system for disk-flutter in rotating storage systems

A hard disk drive that can suppress an increase of fluttering and power consumption at high rotation speed by increasing the seek speed of a magnetic head is disclosed. An enclosure case has a 3.5 inch form factor, and a magnetic disk has an outer diameter of, for example, 84 mm. A center of the magnetic disk is shifted from a center of the enclosure case in the width direction. Owing to this, by designing a larger voice coil, it is possible to increase the driving speed of the actuator.

Disk drive apparatus and hard disk drive

A stator magnet according to a first embodiment of the present invention forms a voice coil motor with a closed coil. The closed coil is supported by an actuator arm in a rotatable manner and at a predetermined rotation angle. The closed coil has first and second side edges that extend along different lines in radial directions whose center is a center of rotation of the actuator arm. It also has an outer edge that connects edges of outer sides of the first and second side edges with viewed from the radial direction, and extends along an arc whose center is the center of rotation. A first magnetic pole region is located within a moving area of the first side edge to act on the first side edge. A second magnetic pole region is located within a moving area of the second side edge to act on the second side edge. The polarity of the second magnetic pole region is opposite to the polarity of the first magnetic pole region. A third magnetic pole region is located within a moving area of the outer edge to act on the outer edge. The polarity of the third magnetic pole region is the same as the polarity of the first magnetic pole region.

Magnet design for active damping of disk drive actuator

An arrangement structure of the printed circuit board and the interface cable connector of a magnetic disk drive for increasing the degree of freedom of the arrangement of a spindle motor, and for minimizing the size of a printed circuit board. An interface cable connector is disposed on the side opposite to the spindle motor, and the printed circuit board is sized so as not to contact with the spindle motor in the height direction. This allows the degree of freedom of the arrangement of the spindle motor to increase. Further, the distance between the interface cable connector and the preamplifier connector on the printed circuit board is short. Thus, the size of the printed circuit board can be made as small as possible.

Arrangement structure of the printed circuit board and the interface cable connector of a magnetic disk drive

A method and system for reducing positioning noise in a data storage system are provided. An access device is positioned over a data storage medium using a stream of bursts stored on the medium. The bursts are sensed at a frequency determined by the rate at which the medium is moved relative to a sensing device. Output positioning values are provided to position the access device at a frequency higher than the frequency at which the positioning bursts are sensed, and/or at random times. The random times may be calculated as random advances or delays from time points occurring at a fixed frequency.

Increased and randomized output sampling to reduce positioning noise in a data storage system

A bearing mechanism of the present invention has a first bearing and a second bearing disposed at different positions in an axial direction. Each bearing has an inner race, an outer race, and balls. A shaft holds the inner races of both bearings in an axially separated manner, while a supporting member holds the outer races of both bearings in an axially separated manner. The balls of the bearings have a different coefficient of linear expansion than that of the inner and outer races. The inner and outer races of each of the bearings are fixed in an axially shifted manner, whereby pre-loaded pressures are applied between both the inner race and the balls, and between both the outer race and the balls. As the temperature changes, the supporting member has a compensation member that can change a distance between the outer races in a changing ratio different from a changing ratio of the distance between the inner races.

Spindle motor structure using ceramic ball bearing for hard disk drive

A hard disk has a servo loop and a rotating storage medium. The rotating storage medium has one or more significant flutter modes at frequencies below a zero cross frequency of a rejection transfer function of the servo loop. The effect of the forgoing is to allow the servo loop to better track a rotating medium that is subject to significant flutter. Peak filters with frequency bands that substantially overlap frequency bands of the significant flutter modes can also be added to the servo loop to further improve tracking. Multiple narrow band filters with frequency bands overlap can be used to cover the spectrum of a single flutter mode. Two lag-lead filters, the frequency responses of which overlap can be used to cover two adjacent significant flutter modes. At frequencies intermediate to the two adjacent flutter, modes, the lead caused by one filter, will be cancelled by the lag caused by the second.

Disk-flutter servo control in rotating storage system with optimum disk thickness

An attachment structure and method for a disk drive apparatus for making the coupling resonance frequency of a hard disk drive the same whether one disk is loaded or a plurality of disks are loaded based upon parameters obtained from a simulation model. The modeling of a coupling vibration for one disk and for two disks is performed using a coupling vibration model of a linear two degree-of-freedom system. The component parts of a spindle motor providing a spring constant K,are adjusted so that the resonance frequency determined by coupling that of a spindle motor with that of the disk(s) is made much the same whether one disk or two disks are loaded. This adjustment enables stable track following to be secured without the need for adding dummy disks and other parts.

Disk drive apparatus, attachment structure, and attachment method

Growing community of inventors

Fujisawa, Japan

Kiyoshi Satoh