Nidec Corporation

Sankyo Seiki Mfg. Co., Ltd

Kabushiki Kaisha Sankyo Seiki Seisakusho

Other

Western Digital Technologies, Inc.

Kazushi Miura

Masato Gomyo

Takehito Tamaoka

Mitsuhiro Takemoto

Takehiko Yazawa

Takayuki Narita

Shigeki Horiki

Tokio Tago

Yoichi Sekii

Takashi Yamamoto

Junya Mizukami

Takayuki Oe

Naoki Sabashi

Masayoshi Saichi

Hideki Kanebako

Masamichi Hayakawa

Katsuya Takahashi

Hironori Ando

Kazuhiko Fukushima

Kazuhiro Sato

Shingo Suginobu

Jonathan M Garbarino

Masaaki Sato

Akinobu Sumiji

Akio Tatsumi

Robert N Lion

Katsuki Yamaguchi

Yoshitsugu Hideshima

Takeo Mizutani

Momoyo Suzuki

Ryouichi Shin

Ryuhei Matsuda

A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion including one communicating hole arranged to extend completely there through from an upper surface to a lower surface thereof, and a cover portion including a hole portion. The axial extension range of the hole portion is arranged to overlap with the axial extension range of the communicating hole in a radial direction. A center of the hole portion is arranged on a plane including a central axis and a center of the communicating hole. The communicating hole and the hole portion are arranged on opposite sides of the central axis. The following inequality is satisfied: V&#x3c;(&#x3c3;/&#x3c3;)&#xb7;V, where &#x3c3;is the density of the sleeve portion, Vis the volume of the communicating hole, &#x3c3;is the density of the cover portion, and Vis the volume of the hole portion.

Disk drive spindle motor with hole volume and component density relationship

A method of manufacturing a bearing mechanism of a motor includes steps a)-e). In step a), a bearing assembly is assembled. In step b), an upper seal gap between an upper thrust portion and an upper hub annular portion is arranged to face downward to increase the width of a gap between an outer tubular portion and a flange portion, or a lower seal gap between the outer tubular portion and a lower hub annular portion is arranged to face downward to increase the width of a gap between the upper thrust portion and the flange portion. In step c), pressure in all gaps is reduced. In step d), lubricating oil is injected into the upper or lower seal gap which faces upward, and a predetermined time or longer is allowed to pass. In step e), pressure is returned to atmospheric pressure.

Method of manufacturing fluid dynamic bearing mechanism, motor, and storage disk drive

A motor includes a stationary portion and a rotating portion. The stationary portion includes a shaft portion and an upper thrust portion. The upper thrust portion includes a tubular first outer circumferential surface arranged radially outside the upper thrust portion, and a tubular second outer circumferential surface arranged above the first outer circumferential surface. The rotating portion includes a sleeve portion, a tubular portion, and an annular cover portion. The annular cover portion includes a plate portion and an inner annular projecting portion arranged to project upward or downward. An inner circumferential surface of the inner annular projecting portion is arranged above an inner circumferential surface of the tubular portion. An upper seal portion includes a surface of a lubricating oil located therein. The inner circumferential surface of the inner annular projecting portion and the second outer circumferential surface are arranged opposite to each other with an axially extending gap therebetween.

Spindle motor and storage disk drive

A motor includes a seal cap and a tubular portion. The seal cap includes a first seal cap lower surface which is an annular surface facing axially downward, and a second seal cap lower surface which is an annular surface facing axially downward and arranged radially outward of the first seal cap lower surface. The tubular portion includes a first tubular portion upper surface which is an annular surface arranged axially opposite to the first seal cap lower surface, and a second tubular portion upper surface which is an annular surface arranged radially outward of the first tubular portion upper surface and in contact with the second seal cap lower surface. The first tubular portion upper surface includes an oil-repellent film region covered with an oil-repellent film. A substantially annular radially extending gap is defined between the first tubular portion upper surface and the first seal cap lower surface.

A spindle motor includes a base portion, a rotor hub, a stator, and a circuit board. The base portion preferably includes a through hole and is arranged to spread out radially around a central axis. The rotor hub is arranged above the base portion to rotate about the central axis. The stator is arranged above the base portion, and includes coils each including at least one lead wire. The circuit board is arranged radially outward of the through hole, and arranged on a lower surface of the base portion. The base portion includes a communicating groove arranged to join the through hole and the circuit board to each other. The at least one lead wire of the coils is arranged to pass inside the through hole and the communicating groove to be electrically connected to the circuit board. The through hole is sealed with a sealant.

Spindle motor having connecting mechanism connecting lead wire and circuit board, and storage disk drive having the same

In a motor, an annular radially extending gap is defined between an outer annular surface and a lower surface of an annular cover portion. The radially extending gap has an axial width smaller than a maximum width of an upper seal portion defined between an outer circumferential surface of an upper thrust portion and an inner circumferential surface of a tubular portion. An annular axially extending gap is defined between an inner cylindrical surface and a radially inner edge of the annular cover portion. The axially extending gap has a radial width smaller than the maximum width of the upper seal portion.

Spindle motor including fluid bearing and storage disk drive including the same

A spindle motor according to an embodiment of the invention includes a rotor hub formed of a ferromagnetic material and a rotor magnet held by the rotor hub. The rotor hub has a flange having a shield surface that faces an upper end surface of the rotor magnet via a clearance in the axial direction and formed of a ferromagnetic material. On the outside in the radial direction of an outer peripheral surface of the rotor magnet in the flange, a rim projected downward from the shield surface of the flange is formed.

Rotor hub, spindle motor, and recording disk driving apparatus

A dynamic pressure bearing apparatus provides a configuration in which the label on which desired data is visibly printed is arranged in a manner that the label does not overlap with a cover plate at least in the area where the label faces the rotary shaft in the shaft direction where the cover plate covers the opening of the bearing sleeve. Deformation of the cover plate that may occur during attachment of the label onto the cover plate is thus prevented. The position of the cover plate is leveled with the position of the label, which makes height reduction of the bearing apparatus possible. Subsequently, even when a relatively thick label is attached onto the frame, the dynamic pressure bearing apparatus can still be made thinner without adversely affecting performance or life thereof.

Dynamic pressure bearing apparatus

The present invention provides a composition comprising an untreated or treated culture of a mixed microorganism and a functional food comprising said composition. A composition comprising an untreated or treated culture of a mixed microorganism comprising at least three lactic acid bacteria selected from the group consisting of and , mixed with , and a functional food comprising said composition.

Compositions comprising saccharomyces cerevisiae and lactic acid bacteria

A pair of thrust hydrodynamic bearing portions are made to communicate with each other to form fluid circulating passages for equalizing a pressure imbalance between both thrust hydrodynamic bearing portions. Even in a case where a pressure imbalance has occurred in a lubricating fluid inside the thrust hydrodynamic bearing portions due to such a cause as the deformation of a thrust plate, the lubricating fluid is allowed to move between the pair of upper and lower thrust hydrodynamic bearing portions through the fluid circulating passages so as to overcome the pressure imbalance, thereby making it possible to stably obtain the amount of floatation in the thrust hydrodynamic bearing portions.

Hydrodynamic bearing device

A method for manufacturing a tool to form a dynamic pressure bearing in which at least one of the bearing surfaces has a plurality of pressure generating grooves defined by projections and in which lubricating fluid is contained in the grooves to provide lubrication between the bearing surfaces when they rotate relative to one another. A flat bevel is created at one or more of the corners of each of the projections that define the grooves thereby generating a wedge-shaped space that communicates between the grooves and the gap between the bearing surfaces. This wedge-shaped space facilitates passage of lubricating fluid from the groove to the gap when movement, normally rotation, occurs between the two bearing surfaces thereby minimizing wear between the surfaces.

Method for manufacturing a tool that is used to form dynamic pressure generating grooves in dynamic pressure bearing devices

A thrust dynamic pressure bearing apparatus includes a shaft member and a thrust plate having a fixing hole that is provided with chamfered sections Ca and Cb at the fixing hole. The shaft member is shrink fitted or pressure inserted in the fixing hole of the thrust plate. The chamfered sections Ca and Cb have axial lengths La and Lb in the axial direction. Dimensional relations of the axial lengths La and Lb in the chamfered sections Ca and Cb are set to be within a specified range to evenly distribute the bonding force of the thrust plate applied to the shaft member along the axial direction.

Thrust dynamic pressure bearing apparatus and method for manufacturing the same

In a dynamic pressure bearing device which has a shaft ( ), a bearing ( ) rotatable relative to the shaft ( ), and capillary seal portions ( ) for holding a lubricating fluid ( ) in a bearing clearance and in which the shaft ( ) and the bearing ( ) are relatively rotatably supported by dynamic pressure of the lubricating fluid ( ) in the bearing clearance is scattered by centrifugal force so that the lubricating fluid ( ) is kept in a constant quantity by the capillary seal portions ( ).

Method of producing fluid bearing device

A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Growing community of inventors

Nagano, Japan

Kazushi Miura