Seiko Instruments Inc

Sumitomo Cement Co., Ltd.

Sumitomo Osaka Cement Co., Ltd.

Tadao Iwaki

Yasuyuki Mitsuoka

Naoki Kawawada

Nobuyuki Kasama

Tsuneo Yamazaki

Hiromitsu Goto

Isamu Takehara

Koji Nitadori

Yoshikazu Kojima

Hiroaki Takasu

Kunihiro Takahashi

Takafumi Suzuki

Yukihiro Nakayama

Atsushi Ohta

Atsushi Ota

Yukiya Funanami

Toshiharu Kogure

Shuhei Yamamoto

Shigeru Senbonmatsu

Ryuichi Takano

Shigeru Ohki

Ryouji Yoneyama

Katsuki Matsushita

Takahumi Suzuki

Takashi Ishida

Atsushi Sakurai

Hiroshi Okano

Masaaki Kamiya

Naoki Kato

Kunio Nakajima

Hiroshi Kuroda

Kouji Kawaguchi

Toshiharu Takesue

Mizuaki Suzuki

Tatsuru Sato

Yasuhiro Takemura

Junko Yamanaka

Tomohiro Yoshikawa

Shinichi Hayashizaki

Ryoji Yoneyama

Mitsuharu Iwamoto

Rieko Sekura

Katsushige Konno

Hirotada Shimaguchi

Seiji Kuwabara

Kimio Komata

Satoshi Oohama

Hiroaki Namiki

Yasuyki Mitsuoka

A liquid dynamic pressure bearing has bearing portions provided at opposite ends of a rotor shaft. The bearing portions are spaced from the rotor shaft by a gap having only one opening portion to maintain lubrication oil therein. A capillary oil sealing portion is formed at the opening portion to prevent evaporation and leakage of oil. Inside the bearing portions, journal bearings are formed at the central axis of the rotor shaft to prevent precession of the rotor shaft. A driving mechanism for driving the rotor shaft and a load are formed between the bearing portions to provide a stable spindle motor resistant to external vibration.

Liquid dynamic pressure bearing and spindle motor, hard-disk driving unit, and scanner motor using the bearing

A motor has an armature disposed on one of a rotor and a stator and a permanent magnet disposed on the other of the rotor and the stator. The permanent magnet has skewed magnetic poles being magnetized so that a boundary between each pair of skewed magnetic poles is generally S-shaped and opposed areas of pole surfaces of the permanent magnet and the armature gradually increase when the pole surface of the permanent magnet enters a magnetic field region of the pole surface of the armature or gradually decrease when the pole surface of the permanent magnet leaves a magnetic field region of the pole surface of the armature.

Motor

A double sleeve type dynamic bearing comprises a fixed shaft having at least one end fixedly mountable to an apparatus in which the bearing is utilized, a rotary sleeve arranged coaxially with the fixed shaft so that a first fine gap is formed therebetween, a fixed sleeve arranged coaxially with the rotary sleeve so that a second fine gap is formed therebetween, and a lubrication oil filled in the fine gaps. The first fine gap and the second fine gap each have an open end exposed to air outside the bearing and an opposite end that is not exposed to the air, the opposite ends being in communication with each other. A holding member holds the fixed shaft and the fixed sleeve and is disposed adjacent to a lower end surface of the rotary sleeve to form a third fine gap between the holding member and the lower end surface of the rotary sleeve. The third fine gap is formed with a thrust dynamic pressure producing groove, and opposite ends of the first and second fine gaps meet each other through the third fine gap. A peripheral surface of at least one of the fixed shaft, the rotary sleeve and the fixed sleeve forming at least one of the first and second fine gaps has a dynamic pressure producing groove formed therein.

Hydraulic dynamic bearing and spindle motor and rotary assembly provided

A method for lubricating a part without leaving air bubbles includes the steps of assembling components so that an open end is formed for application of lubricating fluid and a fluid path is provided through which the lubricating fluid is to be circulated, introducing the lubricating fluid into the open end and applying a centrifugal force to the component by moving the component about a circular path so that the centrifugal force causes the lubricating fluid to be urged throughout the fluid path. The method is used in an embodiment to lubricate a dynamic pressure bearing having a gap between relatively moving parts. The gap has an open end into which the lubrication fluid is dripped and a closed end. During movement of the bearing about a circular path, the fluid is urged from the open end to the closed end.

Method for lubricating a fluid dynamic pressure bearing

In order to alleviate mutual interference between axial dynamic pressure portions and a radial dynamic pressure portion in a ring-like hydraulic dynamic pressure bearing, in the case of a ring-like hydraulic dynamic pressure bearing constituted by supporting a shaft portion constituted by fixing a ring to an end portion A of a shaft main body by a bearing portion , ring-like spaces and for storing lubricant for generating dynamic pressure are provided along contiguous portions of the radial dynamic pressure bearing portion and the axial dynamic pressure bearing portions formed between the ring and the bearing portion , and the ring-like spaces and are maintained at atmospheric pressure via paths formed at the bearing portion to thereby prevent negative pressure from generating at boundary regions of the two dynamic pressure bearing portions.

Hydraulic dynamic bearing and spindle motor

The present invention is a double sleeve type fluid dynamic pressure bearing, comprising a fixed shaft having respective ends to be fixed to a utilized apparatus; a rotary sleeve arranged to provide a first fine gap between an inner peripheral surface thereof and an outer peripheral surface of the fixed shaft, a fixed sleeve arranged to provide a second fine gap between an inner peripheral surface thereof and an outer peripheral surface of the rotary sleeve, a holder member arranged to cooperate with a lower end surface of the rotary sleeve to provide a third gap, and wherein the first fine gap and the second fine gap are formed with radial dynamic pressure producing grooves while the third fine gap is formed with a thrust dynamic pressure producing groove, the first, second and third fine gaps being filled with lubrication oil, the first fine gap and the second fine gap having one ends made as opening ends contacting with the air and the other ends made as closed ends communicated with each other through the third fine gap.

A spindle motor comprises a base, a stator coil connected to the base, and a sleeve-and-bearing unit connected to a central portion of the base. The sleeve-and-bearing unit has a sleeve and a bearing section mounted in the sleeve having a linear expansion coefficient greater than that of the sleeve. The sleeve has a groove disposed in an outer peripheral surface thereof for receiving an adhesive material for connecting the base to the outer peripheral surface of the sleeve. A rotor unit is connected to the sleeve-and-bearing unit for undergoing rotation relative to the sleeve-and-bearing unit. The rotor unit has a shaft section supported by the bearing section for undergoing rotation, a hub connected to the shaft section for rotation therewith, and a rotor magnet connected to the hub and disposed opposite to and spaced apart from the stator coil.

Spindle motor

A hydraulic dynamic bearing has a rotational assembly and a bearing member for rotationally supporting the rotational assembly. The bearing member has a main body having a recess portion and a cover for covering an open end of the recess portion. The rotational assembly has a shaft main body having an end portion extending into the recess of the bearing main body for undergoing rotation relative thereto and a ring member disposed in the recess of the bearing main body. The ring member is connected to the end portion of the shaft main body for rotation therewith. Axial dynamic pressure generating grooves are formed in upper and lower surface portions of the ring member for generating axial dynamic pressure during rotation of the rotational assembly. Radial dynamic pressure generating grooves are formed in an outer peripheral surface portion of the ring member for generating radial dynamic pressure during rotation of the rotational assembly. Spaces are formed between the bearing member and the rotational assembly for storing a lubricant.

Hydraulic dynamic bearing and spindle motor utilizing hydraulic dynamic bearing

In a method for assembling a spindle motor having a liquid dynamic pressure bearing having a flanged shaft member formed by press-fitting a dynamic pressure ring member on a cylindrical member, a hub is press-fit on the flanged shaft member without causing deviation in the press-fit position of the dynamic pressure ring member. A hub press-fitting apparatus press fits a mount hole of the hub on a cylindrical end portion of the cylindrical member. The hub press-fitting apparatus comprises a hub holding member, a rotation shaft member, a coupling member, and an anti-rotation member. During assembly, a temporary coupling between the hub press-fitting apparatus and the liquid dynamic pressure bearing is made by screwing a threaded tap in a tap hole provided in an end face of the cylindrical member.

Spindle motor and method of formation

To provide a semiconductor substrate and a light-valve semiconductor substrate capable of preventing the threshold value of a MOS transistor on a single-crystal silicon device forming layer from increasing and forming a MOS integrated circuit with a high reliability even for a long-time operation. A semiconductor substrate and a light-valve semiconductor substrate comprising a single-crystal silicon thin-film device forming layer,formed above an insulating substrate,through an adhesive layer,and an insulating layer,formed on the single-crystal silicon thin-film device forming layer, wherein a heat conductive layers,and,made of a material with a high heat conductivity are arranged between the single-crystal silicon thin-film device forming layer and the adhesive layer and on the insulating layer.

Semiconductor device

A semiconductor substrate is utilized to integrally form a drive circuit and a pixel array to produce a transparent semiconductor device for a light valve. The semiconductor device for a light valve is constructed of a semiconductor substrate composed of a bulk single crystal silicon having an opaque thick portion and a thin transparent portion. A pixel array is formed in the transparent portion. A drive circuit is formed in a top face of the opaque portion. A transparent support substrate is laminated to the top face of the semiconductor substrate for reinforcement. A bulk portion of the semiconductor substrate is removed from a back face thereof by selective etching to provide the transparent portion.

Method of forming a semiconductor device for a light valve

A spindle motor has a rotor, a stator and an air dynamic pressure bearing for supporting the rotor for rotation about a rotational axis relative to the stator. The air dynamic pressure bearing comprises a first dynamic pressure bearing portion and a second dynamic pressure bearing portion. The first dynamic pressure bearing portion comprises a convex side bearing member having a conical convex portion, a concave side bearing member having a conical concave portion receiving the conical convex portion, and dynamic pressure generating grooves formed on one of a surface of the conical convex portion and a surface of the conical concave portion. The second dynamic pressure bearing portion comprises a shaft having a first end fixed to the concave side bearing member and extending along the rotational axis, a bore formed in the convex side bearing member for receiving a second end of the shaft to permit rotation of the convex side bearing member relative to the concave side bearing member about the shaft, and dynamic pressure grooves formed on one of an outer circumferential surface of the shaft and an inner circumferential surface of the bore.

Spindle motor having air dynamic pressure bearing and rotating device

A recording unit has an illuminating device for projecting light on an original to form an original image, and an optical device which focuses the original image formed by the illuminating device. A light control plate has a slit for allowing a portion of the original image focused by the optical device to pass through. The light which passes through the slit of the light control plate is guided onto a print head which ejects ink on a recording medium when exposed to the light.

Recording systems and recording units employed in the recording systems

A spindle motor having a simplified construction with reduced axial and radial deflection while avoiding the half whirl phenomenon includes a motor frame, a rotating shaft supporting a rotor, a stator and stator coil, a permanent magnet opposing the stator, and a liquid dynamic pressure bearing. Magnetic centers of the permanent magnet and stator coil, in the axial direction of the rotating shaft, are substantially matched. The liquid dynamic pressure bearing comprises opposing surfaces of the rotating shaft and the housing. The rotating shaft has a disk-shaped thrust bearing portion disposed in a first portion of a cylindrical hole of the housing, and a radial bearing portion disposed in a second portion of the cylindrical hole. Lubricating oil fills a space between the cylindrical hole and the thrust bearing portion and radial bearing portion, and a presser ring is pressed and fixed into a third portion of the cylindrical hole to seal the bearing. A boss portion of the rotor is fixed to a rotor supporting portion of the rotating shaft so that an inner peripheral surface of the boss portion mates with an outer peripheral surface of the rotor supporting portion. The rotating shaft has three axially-spaced portions, with the disk-shaped thrust bearing portion formed between and having a larger diameter than the other portions. A stage is provided between the thrust bearing portion and the rotor supporting portion to serve as a seat for installation of the boss portion.

Spindle motor and rotator device

A polarizing type optical apparatus has a first polarizing element disposed in a path of an incident luminous flux produced by a light source and a second polarizing element disposed in the path of a luminous flux reflected from the first polarizing element. The first polarizing element has a p polarized light component transmitting characteristic which varies less with respect to an incident angle of a luminous flux than that of the second polarizing element and has a p polarized light component transmittance which is higher than that of the second polarizing element, and the second polarizing element has an s polarized light component transmitting characteristic which varies less with respect to an incident angle of a luminous flux than that of the first polarizing element and has an s polarized light component transmittance which is lower than that of the first polarizing element, such that the incident luminous flux produced by the light source is irradiated onto the first polarizing element, the luminous flux reflected by the first polarizing element consists mainly of an s polarized light component, and the luminous flux reflected by the second polarizing element consists of a substantially pure s polarized light component.

Polarizing type optical apparatus

Growing community of inventors

Chiba, Japan

Tadao Iwaki