Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Hiromitsu Noda

Shigeo Obata

Kenichi Miyamori

Shozoh Shiraga

Hiromi Kita

Hideki Kuwajima

Kaoru Matsuoka

Masahide Onishi

Yusuke Baba

Tetsuya Koma

Mayuko Okada

Yasunori Tomino

Tamotsu Ohta

Yoshiro Ueno

The present invention relates to a rotation angle detection device mainly used for rotation angle detection of a steering wheel of an automobile and the like. In the rotation angle detection device of the present invention, support portions for supporting lower surfaces of magnets and retention portions for retaining upper surfaces of the magnets are provided in respective accommodation portions of first and second detection bodies. The magnets are turned in the accommodation portions, and the magnets are press-fitted into lower surfaces of the retention portions so as to be retained and fixed between the support portions and the retention portions. Thereby, an inexpensive rotation angle detection device in which the magnets can be easily and reliably installed in the detection bodies with a simple configuration without individually using holders can be realized.

Rotation angle detection device

A rotation angle detection device includes rotary bodyrotating in linked motion with a steering wheel; detectorsandthat rotate in linked motion with rotary body; detecting partsandfor detecting rotation of detectorsand; control partfor detecting a rotation angle of rotary bodyfrom a detection signal from detecting partsand; latching bodyfor latching the rotation of rotary body; and casecontaining rotary body, detection partsand, control partand latching body. Latching bodyincludes latching partB urged by elastic bodyand brought into elastic contact with an outer periphery of rotary body; and releasing partC for releasing an elastic contact of latching partB to rotary bodyand a part of which is exposed to the outside of case

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 rotation angle detector includes a rotator, first and second detecting bodies, an auxiliary detecting body, first and second detectors, an auxiliary detector, and a controller. The first detecting body rotates in association with the rotator, and the first detector detects rotation of the first detecting body. The second detecting body rotates in association with the first detecting body at a different speed therefrom, and the second detector detects rotation of the second detecting body. The auxiliary detecting body is engaged with the rotator at a position symmetrical to the first detecting body with respect to a rotation axis of the rotator. The auxiliary detector detects rotation of the auxiliary detecting body. The controller detects a rotation angle of the rotator based on detection signals from the first, second, and auxiliary detectors.

Rotation angle detector

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 rotational angle detector has a rotary body, a first detecting unit rotating in cooperation with the rotary body, a second detecting unit rotating in cooperation with the first detecting unit, and an auxiliary detecting unit rotating in cooperation with the rotary body and the second detecting unit. The rotational angle detector has a first detecting element, a second detecting element, and a controller. The first detecting element detects rotation of the first detecting unit, and the second detecting element detects rotation of the second detecting unit. The controller detects a rotational angle of the rotary body based on a detection signal supplied from the first detecting element and a detection signal supplied from the second detecting element.

Rotational angle detector for detecting a rotational angle of a rotating body

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

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.

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Osaka, Japan

Hiromitsu Noda