Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Shigeo Obata

Kenichi Miyamori

Hiromitsu Noda

Hideki Kuwajima

Kaoru Matsuoka

Hiromi Kita

Makoto Miyamoto

Koichi Shinohara

Hiroshi Inoue

Daisuke Ito

Takafumi Asada

Shinji Tanaka

Yoshihiro Ueno

Hiroaki Saito

Tatsuhiko Inagaki

Kenichi Sakamoto

Masashi Omura

Junichi Nakamura

Naoshi Kainoh

Akihito Shirai

Hisashi Takahashi

Tomohiro Haga

Atsushi Imai

Hiromichi Inomata

Kenji Kawamata

Youichi Nishimoto

Akihiko Wakitani

Yoshinobu Ono

Yoshiro Ueno

In a hydrodynamic bearing device with which the lubricant is prevented from leaking to the outside, and good seal performance can be maintained, and in a spindle motor equipped with this hydrodynamic bearing device, the hydrodynamic bearing device includes a shaft, a sleeve, a lubricant that fills a microscopic gap, a radial bearing portion, a thrust bearing portion, and a bearing seal portion. The value of a function P/V, where Vis a fluctuation volume of the sleeve in the axial direction and Pis a capillary pressure index at a vapor-liquid interface located near the opened end of the bearing seal portion, is at least a specific value.

Hydrodynamic bearing device, and spindle motor equipped with same

A disc driving motor of the invention includes a base, a hub having a ring-shaped disc receiving face on which a disc is placed, a hydrodynamic bearing rotatably supporting the hub, a motor unit mounted on the base, the motor unit having an outer diameter larger than that of the disc receiving face and applying a rotational force to the hub, and a magnetic shield plate disposed on an axial clearance formed between the disc and the motor unit when the disc is placed on the disc receiving face. The magnetic shield plate has an opposed face opposed to the disc when the disc is placed on the receiving face, the opposed face being inclined toward the disc receiving face.

Spindle motor with a magnetic shield plate having an inclined annular face

A disk apparatus includes a hub having a disk inserting portion having a cylindrical plane in the outer part of one end and a disk receiving portion having a flat part and being pivotably supported, a head having an inner hole through which the disk inserting portion is fitted, facing toward one face of a disk, levitating and scanning above the disk and reading a signal recorded on the disk or recording a signal on the disk, the disk being held by the disk receiving portion, and a clamp unit holding the disk with the disk receiving portion. In this case, the disk receiving portion has an inclined or declined plane. Thus, the amount and direction of deformation of the disk, which is caused by clamping, are defined, and obtaining a stable amount of head levitation independently of temperature changes can prevent the occurrence of a distortion of the disk.

Disk device

A spindle motor and a disk drive device are provided that have a high operation efficiency of the motor, that does not leak oil, and that has an improved stability by decreasing a runout component in the direction of the rotation axis. The spindle motor includes a rotor hub (20) composed of a disk-like flange (201) and a cylinder-shaped shaft (203); a ring-shaped rotating magnet (16) fastened on one main surface of the flange (201); an armature (14) facing the rotating magnet (16); a sleeve (80) rotatably supporting the shaft (203); and a chassis (15) fixing the armature (14) and the sleeve (80). The flange (201) and the shaft (203) are integrally formed with magnetic material; a protrusion is not provided between a mounting surface (204) for mounting the rotating magnet (16) thereon and a counter-face surface (205) facing the end surface of the sleeve; and the mounting surface (204) and the counter-face surface (205) are orthogonal to the direction of the central axis (A-A') of the shaft (203), and in a level plane; or the mounting surface (204) is recessed stepwise from the counter-face surface (205) toward the disk mounting portion (202).

Spindle motor and disk drive device using the same

A thrust dynamic pressure bearing with high inclination-resistant rigidity against axis runout and additionally low bearing loss torque is implemented. Herringbone grooves () having intermediate bends () are provided on rotating-side bearing surface () provided on the rotating-side bearing member. When rotating-side bearing surface () rotates in direction A (clockwise), lubricating oil generates dynamic pressure in an area centering on intermediate bend () along radially outer part () and radially inner part () of herringbone groove (). As a result that groove width (G) of a dynamic pressure generating groove and width (L) of a land adjacent to the dynamic pressure generating groove holds G&#x3e;L at an arbitrary radius () position, a thrust dynamic pressure bearing with high inclination-resistant rigidity and additionally low bearing loss torque is provided.

Thrust dynamic pressure bearing, spindle motor using thereof, and information recording/reproducing device using the spindle motor

A hydrodynamic bearing device which can improve workability of injecting a lube repellant and effectively prevent leakage of a lubricant, a method for manufacturing the same, a spindle motor, and a recording and reproduction apparatus are provided. A hydrodynamic bearing deviceincludes a lube repellantwhich is applied in a circular shape by a predetermined distance in a radial direction from a portion of an upper surface of a second thrust flangewhere it is connected to a shaftand a lube repellantwhich is applied in a circular shape on an outer peripheral surface of the second thrust flangebelow from an upper end in the radial direction by a predetermined distance. The lube repellantis applied near the upper end portion in a gap formed between the outer peripheral surface of the second thrust flangeand an inner peripheral surface of an outer sleeve

Hydrodynamic bearing device, method for manufacturing the same, spindle motor and recording and reproduction apparatus

The disclosed is a spindle motor most suitable for magnetic disk drives, optical disk drives or the like capable of constraining undesirable cogging torques to a low level and of winding a coil regularly. In particular, the inward periphery of magnetic pole of iron core for a stator includes of an arc shaped surface concentrically to the outward periphery of rotor magnet and a pair of flat surfaces, generally perpendicular to the centerline of magnetic pole, attached to both sides of the arc shaped surface peripherally. The configuration can reduce the cogging torques without any decrease in motor efficiency.

Spindle motor

The stop ring having a surface nearly vertical to the rotational center axis, which is projected at the inner periphery of the hollow cylinder of the rotor section, and the stepped surface of the fixed shaft secured on the chassis are opposed to each other with a predetermined slight clearance provided therebetween. The clearance is filled with magnetic fluid, and further, a permanent magnet is disposed on the chassis, opposing to the other surface of the stop ring.

Fluid bearing motor, and disk drive mounted with same

Disclosed is a spindle motor and a disk drive unit equipped with the same, having advantages of preventing hard collision between a disk and a signal conversion element due to lifting of rotating components, and avoiding the signal conversion element and swing means for positioning the signal conversion element from being damaged irreparably. Specifically, spindle motorcomprises rotor unit, stator, stator-side bearing memberin engagement with rotor-side bearing memberto form a shaft rotating type fluid bearing, and chassis. Rotor hubhas hollow cylinder portionnear central axisof rotation, and cylindrical portionof support columnsecured to chassisis positioned inside the hollow space of cylinder portionwithout being in contact thereto. Coveris placed with a bottom side of abutment portionkept in abutment upon an upper end of cylindrical portionof support columnwith a predetermined small clearance provided between upper endof rotor huband the bottom side of abutment portion

Spindle motor and disk drive unit

A spindle motor of small size, thin type, high reliability, and high performance suited to an information recording and reproducing apparatus is presented. Specifically, a rotary disk is composed by integrally forming a disk board, and a rotary shaft of spindle motor, and a bearing is composed by forming dynamic pressure generating grooves in the rotary shaft of the rotary disk. As a result, small size and thin structure are realized, surface deflection of the disk during rotation of the spindle motor, and its axial center deflection are substantially decreased, and moreover the recording density is enhanced, the number of constituent parts is curtailed, and the cost is saved.

Spindle motor, information recording and reproducing apparatus having a spindle motor, and manufacturing method of spindle motor

In order to prevent lubricating oil leakage due to bubbles in a thrust dynamic pressure bearing having herringbone grooves, and to stabilize the bearing performance, and enhance the reliability and durability, auxiliary grooves deeper than pump-in type herringbone grooves for generating dynamic pressure are provided. The bearing inner periphery and bearing outer periphery are linked by a pressure gradient descending slowly, and therefore bubbles present in the bearing inner periphery can be guided to the bearing outer periphery through the auxiliary grooves, and discharged outside of the bearing from the air-liquid interface, so that lubricating oil leakage due to bubbles can be prevented.

Thrust dynamic pressure bearing, spindle motor using the same, and information recording and reproducing apparatus using them

An actuator gripping device which prevents the actuator of the head support device from serious trouble such as damage to the surface of the recording medium due to external shocks. An actuatorcomprises actuator sub-unithaving a tabat one end and provided with a head, and a voice coilmounted at the other end, a pivot pedestalwith a pair of abutments, and a spring platehaving an activating force to push the headtoward the recording medium, and that the actuator gripping device for gripping the actuatorcomprises a rampformed with the first stepped side surfaceand the second stepped side surfacehaving a specified angle respectively at either side of the second planeon which the tabis abutted at the shunt position in stop mode of the recording medium

Disk drive

An information-recording/-reproducing device comprises a rotor assembly formed of a disc portion having information recording layer provided on the main surface and an axle portion, the disc portion being connected at the center of a surface opposite to the main surface with the rotating axle so that the rotating axis crosses at right angle with the main surface of disc portion at the center of rotation, a bearing for supporting the axle of disc portion freely rotatable, a rotating magnet fixed to a rotor yoke, a stator disposed opposing to the rotating magnet, and a motor for rotating the disc portion with the rotating axis of the axle as the center of rotation. Preferably, the disc portion with the rotating axle portion having a round column shape or a cylindrical shape, further may have a shallow hollow in the central part of the main surface which being a surface opposite to the surface having the rotating axle.

Rotor assembly, information-recording/-reproducing device using the rotor assembly and method of assembling the rotor assembly

A method of assembling a rotor structure for a spindle motor for use in an information recording and playback apparatus is provided in which pollution of the recording medium due to gases emitted from adhesives and the like used in the manufacturing process can be prevented. To be more specific, in an assembling process of securing a rotor yoke and a rotating magnet on a disc section, the rotor yoke, the rotating magnet, and the disc section is disposed one after another at predetermined positions of a centering jig used for centering the center of rotation of the rotating magnet and the center of rotation of the disc section. A pressing mechanism is then placed on the disc section to press the disc section, the rotor yoke, and the rotating disc so as to integrate them into one piece. At the same time, emitted gases are exhausted with an exhausting apparatus in a manner such that the direction of flow of the emitted gases is from the main surface of the disc section toward the rotor yoke. With this method, gases and particulates emitted from adhesives are prevented from reaching and adhering on or reacting with the surface of the recording medium, and malfunctioning such as head crash due to degradation and deterioration caused by pollution can be suppressed.

Growing community of inventors

Hyogo, Japan

Shigeo Obata