Hitachi, Ltd.

Kazuhiko Kawakami

Hiroshi Nishida

Katsutoshi Nii

Masaru Muranishi

Kenji Tomida

Yuuichi Yanagase

Noboru Sugiura

Hisanobu Kanamaru

Noriyuki Kumasaka

Kouki Uefune

Shozo Saegusa

Takashi Kouno

Tsuyoshi Takahashi

Junichi Shimada

Shinobu Yoshida

Kazutoshi Kobayashi

Takashi Matsuki

Mitsuyuki Tsuyuki

Noriyoshi Urushiwara

Ryoichi Koshida

Norio Moriyama

Mitsukuni Tsutsui

Terumi Nakazawa

Kouji Harada

Hitoshi Minorikawa

Takashi Yoshinari

Toshiaki Iikubo

The manufacturing method for an electronic circuit device comprises attaching an electronic circuit assembly including a circuit substrate with electronic circuit elements attached to a base, joining lead terminals integrally with the base via frames before molding the lead terminals composed of a different material from that of the base with mold resin, electrically connecting the lead terminals to the electronic circuit assembly, molding the electronic circuit assembly, lead terminals, and flange with mold resin in a batch partially excluding the flange and lead terminals installed on the base, and separating and removing the frames from the lead terminals and base after the molding with the mold resin.

Electronic circuit device and manufacturing method thereof

A spindle motor for magnetic disc device includes a hub having an inside and an outer peripheral side on which a magnetic disc is mounted, a rotary shaft having an axial direction and coupled with the hub so as to be integrally rotated therewith, with the motor being arranged on the inside of the hub. The hub, the rotary shaft and a part of the motor constitute a rotary body. A radial bearing having a length in the axial direction of the rotary shaft, for supporting the rotary body in a direction crossing the rotary shaft, and a thrust bearing for supporting the rotary body in the axial direction of the rotary shaft are provided. The thrust bearing has an outer diameter greater than the length of the radial bearing, and is arranged at a position which is inside of the motor and diametrically inward of the hub.

Spindle motor and magnetic disc device using thereof having radial and thrust bearings

A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing, the rotary shaft being supported by a hydrodynamic pressure thrust bearing and the hydrodynamic pressure radial bearing. An inner diameter D and a width L of the hydrodynamic pressure radial bearing having a relationship of L/D<1.

Spindle motor and magnetic disc device with hydrodynamic bearings

A outer circumferential part of a body to be coupled having an annular groove formed in the outer periphery of a shaft is press-fitted into the inner circumferential part of a coupling hole in the central portion of a hub , the vicinity of the hole in the end of the hub is plastic-deformed over the whole periphery, and material for the hub is caused to plastic-flow so as to bury a recess of the shaft, and to apply compression stress to the shaft, whereby a coupling force between a thin hub and a small diameter shaft is obtained by shearing force and compressing force of the material for the hub.

Press-fit and plastic-flow coupling of a shaft to a hub of a disk device

A rotary shaft is rotatably supported by a hydrodynamic fluid radial bearing and a hydrodynamic fluid thrust bearing which are excellent in shock resistance, an bearing arrangement in which vibration in a translation mode of the shaft, among vibration components caused by unbalance force exerted to the rotary shaft, is supported by the radial bearing, and vibration in conical mode is supported by the thrust bearing, magnetic fluid is used as lubrication oil, and a permanent magnet is located between the radial bearing and the thrust bearing so as to apply a magnetic attracting force between the rotary shaft and the thrust bearing so as to carry out axial positioning in order to use the magnetic disc device in an arbitrary attaching posture. With this arrangement, the magnetic disc device using such a bearing arrangement can enhance portability, thinning and antishock ability, and reduce noise and power consumption, thereby it is possible to provide a note-type personal computer with a high degree of reliability.

Spindle motor and magnetic disc device with hydrodynamic bearing

A disk drive unit includes a rotary member, which has a spindle, and has an information-recording disk fixedly mounted thereon, and a bearing unit rotatably supporting the spindle. The bearing unit includes a radial bearing device, provided in opposed relation to an outer peripheral surface of the spindle, and a thrust bearing device provided in opposed relation to a distal end surface of the spindle. The radial bearing device has a concentric arc-shaped bearing surface, which is concentric with the circular outer periphery of the spindle, and a non-concentric arc-shaped bearing surface which is non-concentric with the circular outer periphery of the spindle. The disk drive unit further includes a motor for imparting a rotational force to the spindle, and a lubricating fluid filled in the bearing unit.

Disk drive unit with hydrodynamic fluid bearing unit and disk device with said drive unit

A movement detecting device having a light transmitter 44 and a spaced light receiver 46, with a moving plate 32 containing slit apertures therein being positioned between the transmitter and receiver for interrupting the light path between the transmitter and the receiver in dependence upon the motion of the moving plate. So as to improve the clarity of light detection, stationary apertured plates 56U, 56D are unitarily formed and are positioned on respective sides of the moving plate and adjacent a respective one of the transmitter or receiver. The stationary apertured plates 56U, 56D may be formed from a single sheet of material (FIG. 18), or from two separate sheets connectingly joined by a flanged pin (FIG. 12), or a combination thereof. The unitarily formed stationary apertured plates 56U, 56D may be directly molded into a support housing (38, 60, 62 in FIG. 8) with locating holes 64, 66 for the light transmitter 44 and light receiver 46, or may be formed in a molded sub assembly (FIG. 5) prior to moulding into a support housing (FIGS. 4 and 7).

Movement detecting device

An ignition coil in which an ignition coil is incorporated in a distributor housing is characterized in that the ignition coil has an annular core, and is disposed in the distributor housing so that the annular core surrounds a distributor-shaft support portion of the housing.

Ignition coil-incorporated distributor for internal combustion engines

A distributor for an internal combustion engine has a housing, a shaft inserted in the housing, a head mounted on the shaft, a cap attached to the housing so as to cover the rotor head, a signal detector accommodated in the housing, a connector projecting outside the housing, and an ignition coil accommodated in the housing. The housing has a cut-out portion formed in a side wall thereof from an abutment between the cap and the housing and extending toward the bottom of the housing for receiving the connector, and the cap and the connector are tightly engaged with the housing through a gasket. Silicon rubber is charged in the gap between the housing and the ignition coil. A heat release plate may be provided between the housing and the signal detector so that a path formed by the plate and the housing and surrounding a section of the core is electrically cut off, whereby no current flows in the path.

Distributor for internal combustion engine

An electronic device for an automobile is roughly divided into individual parts and control circuit elements which are mounted in a casing divided into two compartments, according to the present invention. The individual parts are arranged in one compartment and are covered with silicone rubber to improve their water resistance. The control circuit elements are arranged in the other compartment and are covered with a silicone gel to prevent any stresses acting upon the control circuit elements, such as ICs, and provide these elements with moisture resistance. The control circuit elements are bonded by high-temperature solder to improve their heat resistance, but the individual parts are bonded by eutectic solder.

Electronic device for automobile

A rotational angle detecting apparatus comprises a rotary disc having first protrusions for an angle signal provided along the outer periphery of the disc and second protrusion for a reference signal arranged adjacent to the first protrusions in the thickness direction of the disc. A pick-up assembly is disposed to face the second protrusion to sense the rotationl position thereof. The sensed signal including noise components due to a magnetic coupling between the pick-up assembly and the first protrusions is subject to an integration and then applied to a level detector to generate a first pulse signal which occurs only during the integration signal being greater than a predetermined threshold level. On the other hand, a second pulse signal is produced by shaping the sensed signal. The first and second pulse signals are applied to an AND logic gate from which an output pulse is obtained in synchronism with the rotation of the disc.

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Hitachinaka, Japan

Kazuhiko Kawakami