Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Hiroyuki Kiriyama

Hiroaki Saito

Takafumi Asada

Takao Yoshitsugu

Daisuke Ito

Keigo Kusaka

Yukio Honda

Noriyoshi Nishiyama

Shinichiro Kawano

Daisuke Itou

Hiroshi Sawada

Koji Hirata

Makoto Hasegawa

Yoshinari Asano

Toshiyuki Tamamura

Takahisa Kurahayashi

Yoshihito Watanabe

Kenji Terai

Hiroshi Nishiyama

Takao Sawahata

Tomoharu Takeda

Yuji Ozeki

Kouji Nakai

Daisuke Yoshikawa

The cross sectional shape of an axial direction communicating path when viewed in the axial direction is flat in the circumferential direction, and the cross sectional area of the communicating path gradually decreases moving from the center of the cross section toward the both ends in the circumferential direction. When a sleeve and a cover member are bonded with an adhesive, the adhesive is actively made to flow into an adhesive inflow portion.

Hydrodynamic bearing device, and spindle motor and information apparatus equipped with same

In order to prevent oil leakage in a hydrodynamic bearing device comprising an opening section in close proximity to a radial bearing and a lubricating fluid reservoir, a shaft, thrust flange, sleeve, seal plate, and stopper plateare provided, a radial dynamic pressure bearing is formed in a radial clearance between the shaftand sleeve, and a thrust dynamic pressure bearing is formed in a thrust direction clearance between the sleeveand thrust flange. A connecting holeis formed that connects a gap between the sleeveand seal plateand a thrust direction gap between the sleeveand thrust flange. The relationship A&#x3c;B&#x3c;C is satisfied, where A is a radial clearance, B is a clearance between an outer peripheral surface of the shaftand an inner peripheral surface of the seal plate, and C is a clearance between a lower surface of the seal plateand an upper end face of the sleeve

Hydrodynamic bearing device, spindle motor, and recording and reproducing apparatus

A hydrodynamic bearing type rotary device is configured to prevent air from being trapped inside a bearing and causing the bearing to have oil film rupture and NPPR to deteriorate. In the device, a flange having a shape substantially like a disc is provided integrally with a shaft near its lower portion. A sleeve having a bearing hole is fitted to the shaft so as to be relatively rotatable. Hydrodynamic grooves are provided on at least one of an outer periphery of the shaft and an inner periphery of the sleeve. The flange forms a thrust bearing surface with a lower end surface of the sleeve. Hydrodynamic grooves are provided on at least one of the lower surface of the sleeve and an upper surface of the flange. During rotation of the bearing, the hydrodynamic grooves circulate the lubricant. Capillary pressures at respective portions in the lubricant circulation path have different magnitudes. The principle that air tends to move toward the portion having a smaller capillary pressure is utilized to make it difficult for the air to be trapped inside the bearing and to smoothly discharge the air.

Hydrodynamic bearing type rotary device and recording and reproducing apparatus including the same

A hydrodynamic bearing rotary device which can reduce rotation friction, and recording and reproducing apparatus including the same is provided. In the hydrodynamic bearing rotary device, such as hard disc devices, a rotary shaft having a hub on one end is provided in a bearing of a sleeve so as to be rotatable. Thrust hydrodynamic grooves are provided on the other end surface of the rotary shaft, to form a thrust bearing with the thrust plate. A communication path is provided in the sleeve. The second gap between the hub and the sleeve end surface is used as a flow channel and is connected to the communication path. In this way, the rotation friction torque of the thrust bearing can be made sufficiently small, and internal pressure in bonded portions of the rotary shaft or the bottom plate can be suppressed. Thus, the oil can be prevented from oozing out from a small space of the bonded surfaces. Furthermore, the hydrodynamic bearing can be made thin. These effects can be combined to realize an optimal hydrodynamic bearing rotary device.

Hydrodynamic bearing rotary device and information apparatus

In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Hydrodynamic bearing device and disk rotation apparatus

An object of the present invention is to provide a hydrodynamic bearing type rotary device which can improve rotation performance, suppress a friction torque, and reduce power consumption of motor, and a recording and reproducing apparatus including the same. A shaft having a flange on one end and a hub on the other end is provided with a bearing of a sleeve so as to be rotatable. The sleeve includes a communication hole. A third gap between the hub and the sleeve end surface is a flow path, and is connected to the communication hole. Provided that a first gap between a thrust plateand the flangeis S, a second gap between the flangeand a lower end surface of the sleeveis S, and a third gap between the upper end surface of the sleeveand the hubis S, widths of the gaps satisfy the relational expression, S(S+S).

Hydrodynamic bearing rotary device

The present invention aims to improve the efficiency of a clamping step for combining a flange with a shaft and to improve productivity. The shaft and the flange are tentatively combined in the tentative clamping step. In the tentative clamping step, a concave part at the end of the shaft is pressurized by a metal mold such as a ball to be enlarged in an outer circumferential direction, thereby pressurizing this concave part against the inner circumference of the flange so as to fix the concave part. The combined body made by tentatively combining the shaft and the flange is strongly combined in a proper clamping step. In order to correct a distortion such as a warpage of the flange that has been solidly combined by the proper clamping step, sandwiching the flange by the upper and lower metals, the flange is pressurized and a flash molding is carried out.

Hydrodynamic bearing member and manufacturing method thereof

Hydrodynamic bearing device and disk rotating apparatus

A hydrodynamic bearing device with high reliability, with which reductions in size, weight, and thickness can be achieved, as well as a motor and a disk driving apparatus that make use of this hydrodynamic bearing device. The hydrodynamic bearing device comprises a shaft, a thrust flange, a sleeve, a seal plate, and a retaining plate. A radial dynamic pressure bearing is formed in the radial direction gap between the shaft and the sleeve, and a thrust dynamic pressure bearing is formed in the thrust dynamic bearing gap between the sleeve and the thrust flange. A communicating hole is formed for communicating between the gap between the sleeve and the seal plate and the thrust direction gap between the sleeve and the thrust flange. The radial dynamic pressure bearing and/or the thrust dynamic pressure bearing are formed such that a lubricating oil circulates in the gap between the sleeve and the seal plate from the inner peripheral side of the sleeve toward the outer peripheral side.

Hydrodynamic bearing device, motor, and disk driving apparatus

A motor has a stator having a plurality of teeth for receiving windings, a yoke connected to each tooth, and a rotor having permanent magnets facing the stator. An inner wall surface of each tooth faces the rotor with an air-gap therebetween. Each tooth is separated from an adjacent tooth by a slot-open-section extending between a tailing end of the tooth and a leading end of the adjacent tooth. The inner wall surface of each tooth has an arc extending from a center of the slot-open-section toward the tailing end. The air-gap at the tailing end of each tooth is greater than the air-gap at the leading end of each tooth. The inner wall surface of each tooth includes a straight-line tailing section extending from the center of the slot-open-section toward the leading end. The straight-line tailing section extends tangentially from the arc.

Motor with permanent magnet

This invention pertains to a rotor core (,) in which a plurality of core sheets (,) are laminated on one another on a rotor shaft (,). A plurality of slits (,) and a plurality of strips (,) are alternately arranged in a radial direction of each of the core sheets (,) so as to convexly confront a center of each of the core sheets (,) such that an outer peripheral rim (,) is formed between an outer peripheral edge of each of the core sheets (,) and each of opposite ends of each of the slits (,). A stress concentration portion (,) which is provided at a portion (,) of the outer peripheral rim (,) and has a width (L,) larger than that of the remaining portions of the outer peripheral rim (,).

Rotor core for reluctance motor

This invention pertains to a rotor core (,) in which a plurality of core sheets (,) are laminated on one another on a rotor shaft (,). A plurality of slits (,) and a plurality of strips (,) are alternately arranged in a radial direction of each of the core sheets (,) so as to convexly confront a center of each of the core sheets (,) such that an outer peripheral rim (,) is formed between an outer peripheral edge of each of the core sheets (,) and each of opposite ends of each of the slits (,). A stress concentration portion (,) which is provided at a portion (,) of the outer peripheral rim (,) and has a width (L1) larger than that of the remaining portions of the outer peripheral rim (,).

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Ehime, Japan

Hiroyuki Kiriyama