Nidec Corporation

Kyodo Yushi Co., Ltd.

Takayuki Oe

Junya Mizukami

Takehito Tamaoka

Yoichi Sekii

Takashi Yamamoto

Naoki Sabashi

Hideki Nishimura

Kazushi Miura

Mitsuhiro Takemoto

Shigeki Horiki

Kazuhiro Sato

Kunio Sakurada

Teiichi Hirono

Katsuya Takahashi

Hironori Ando

Iwaki Hirooka

Yoshiki Okayama

Satoru Sodeoka

Yuji Hagiwara

Kazunori Usui

Akira Mukai

Rentaro Kanzawa

Sayuri Tsubata

The invention provides a lubricating oil for fluid dynamic bearing including as a base oil a monoester oil free of unsaturated bond, and having an absolute viscosity of 2.0 to 3.0 mPa&#xb7;s at 100&#xb0; C. a viscosity index of 130 or more and a pour point of &#x2212;20&#xb0; C. or less.

Lubricating oil for fluid dynamic bearing and spindle motor equipped with the lubricating oil

A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion. The sleeve portion includes a communicating hole. A dynamic pressure bearing is defined in a first gap between a shaft portion and the sleeve portion. An upper seal portion and a lower seal portion are arranged radially outward of the dynamic pressure bearing. The upper seal portion and the lower seal portion are arranged in communication with each other through the communicating hole. The communicating hole and a space extending from the upper seal portion to the lower seal portion through the first gap are filled with a lubricating oil. A fixing region where an outer tubular portion and a base portion are fixed to each other is arranged to overlap with the dynamic pressure bearing in a radial direction in plan view.

Spindle motor with fluid dynamic bearing and storage disk drive

A dynamic pressure bearing is defined in a first gap between a shaft portion and a sleeve portion. An upper seal portion extending upward and a lower seal portion extending downward are arranged radially outward of the dynamic pressure bearing. Each of the upper seal portion and the lower seal portion includes a surface including a lubricating oil located therein. The upper seal portion and the lower seal portion are arranged in communication with each other through a communicating hole defined in the sleeve portion. The communicating hole and a space ranging from the upper seal portion to the lower seal portion through the first gap are filled with the lubricating oil. The axial distance between the surfaces of the lubricating oil in the upper seal portion and the lower seal portion is arranged to be shorter than the axial distance between an upper end and a lower end of the dynamic pressure bearing.

A spindle motor includes a stationary portion and a rotating portion. The stationary portion preferably includes a shaft portion, a lower plate portion, and an outer tubular portion. The rotating portion preferably includes an inner tubular portion and a flange portion including a communicating hole. An upper seal portion is arranged radially outward of a first gap, and a lower seal portion is arranged radially outward of a second gap. The upper and lower seal portions are arranged in communication with each other through the communicating hole. The communicating hole and a space extending from the upper seal portion to the lower seal portion through the first gap, the second gap, and a third gap are filled with a lubricating oil. The third gap includes a dynamic pressure generation portion arranged to produce a radially inward pressure acting on the lubricating oil.

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.

In a motor, a stationary portion includes a shaft portion and an upper thrust portion arranged to define a single continuous monolithic member together with the shaft portion, and arranged to extend radially outward from an upper portion of the shaft portion. The shaft portion includes a female screw portion recessed axially downward from an upper end thereof. An upper end of the single continuous monolithic member defined by the shaft portion and the upper thrust portion includes an upper end annular surface arranged to extend radially outward from the female screw portion perpendicularly or substantially perpendicularly to the central axis. An outside diameter of the upper end annular surface is greater than a diameter of an outer circumferential surface of the shaft portion.

Spindle motor including hydrodynamic bearing and storage disk drive including 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 includes a stationary portion and a rotating portion. The stationary portion preferably includes a shaft portion, an upper thrust portion, and an outer tubular portion. The rotating portion preferably includes an inner tubular portion, a flange portion, an upper hub annular portion, and a lower hub annular portion. The flange portion includes a communicating hole. An upper surface of a lubricating oil is located in a fifth gap defined between an upper thrust portion and an upper hub annular portion, while a lower surface of the lubricating oil is located in a sixth gap defined between an outer tubular portion and a lower hub annular portion. The communicating hole and a space extending from the fifth gap to the sixth gap through a fourth gap, a first gap, a second gap, and a third gap are continuously filled with the lubricating oil.

Spindle motor having dynamic pressure fluid bearing for use in a storage disk drive

A bearing apparatus includes a shaft, a thrust cup including an annular potion and a cylindrical portion, a rotating member including a through hole defined therein, and a lubricating oil. A second gap defined between a lower surface of the rotating member and an upper surface of the annular portion of the thrust cup includes a first region in communication with a capillary seal portion, and a second region positioned radially inward of the first region and having an axial dimension smaller than that of the first region. A lower end portion of the through hole is open at a location radially outwardly away from a boundary between the first and second regions, so that a local circulation of the lubricating oil arises within the first region during rotation of the rotating member.

Bearing apparatus, spindle motor, and disk drive apparatus

A chucking device comprises a retainer section for retaining a disc, a guiding section for guiding the disc to the retainer section, and a supporter for supporting the retainer section and the guiding section. The guiding section has a small enough angle for a guiding section side angle of inclination &#x3b8;so as not to make contact with a upward facing disc, of a multilayer disc, thereby reducing a disc loading force.

Chucking device, and motor and disc drive device having loaded thereon a chucking device

An oil dynamic bearing, a motor and a disk drive adapted to be reduced in both size and thickness are disclosed. The oil dynamic bearing (B) includes at least two bearing portions (B, B), each having a bearing near end nearer to the rotational axis or the bearing center of the bearing and a bearing far end farther from the rotational axis or the bearing center of the bearing. The near and bearing far ends are each connected to a taper seal portion, which in turn communicates with the atmosphere. The taper seal portion connected to the bearing near end of the bearing portion (B) and the taper seal portion connected to the bearing near end of the other bearing portion (B) make up a common taper seal portion.

Oil dynamic bearing, motor supported on oil dynamic bearing and disk drive carrying the motor

A gas dynamic pressure bearing is disclosed in which dynamic pressure generating grooves in a radial bearing pump out gas toward a thrust bearing, and dynamic pressure generating grooves in the thrust bearing pump in gas toward the radial bearings. This structure generates high pressure in the lubrication gas in the connecting portions of the radial bearings and thrust bearings. In order to compensate for the movement of gas by means of this pump-out and pump-in operation, a structure is provided that links the two portions of the radial and thrust bearings where the gas pressure is reduced, or connects these two portions with the space surrounding the bearing.

Gas dynamic pressure bearing, spindle motor comprising a gas dynamic pressure bearing, and recording disk drive device and polygon scanner comprising a spindle motor

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Kyoto, Japan

Takayuki Oe