Hitachi Powdered Metals Co., Ltd.

Other

Minebea Company, Limited

Toshikazu Takehana

Katsutoshi Nii

Motohiro Miyasaka

Hidekazu Tokushima

Jun Hirose

Tadayoshi Yano

Yuji Yoshitomi

Hideo Shikata

Zenzo Ishijima

Tsutomu Nozaki

Yukihiro Nakayama

Takashi Matsumura

This invention provides a germanium-containing health promoting appliance which is used by making it into contact with the skin, which is produced at low cost without requiring the after-machining. The health promoting appliance is made of a sintered material composed of 2 to 20% by mass of germanium and the remainder of stainless steel, the fine pores of which are desirably sealed up by a resinous material and it is produced by sintering a green compact of desired shape of powder mixture of the above composition, under the rate of temperature rise of 10&#xb0; C. per minute or less from 800&#xb0; C. to the retaining temperatures of sintering at 1000 to 1300&#xb0; C.

Health promoting appliance

A bearing unit comprises a bearingformed of a sintered metal in which a magnetized magnetic powder is dispersed in its matrix and at least pores exposed on a bearing surface thereof are sealed by impregnation with a resin; a non-magnetic housingaccommodating the bearing; and a lubricating fluid M made of a magnetic fluid.

Bearing unit, production method therefor and spindle motor

A spindle motor having a bearing housing and a thrust bearing fitted in the bearing housing at the lower end of the latter, in which an inclined part is formed on the outer peripheral edge at the lower end of the thrust bearing, and the outer diameter part of the thrust bearing is fitted in a coupling bore formed in the end surface of the bearing housing, the end surface of the bearing housing being pressed uniformly in the axial direction over the entire circumference around the coupling bore to cause the bearing housing to plastically flow around the coupling bore in order to cover the above-mentioned inclined part of the thrust bearing. The above-mentioned covering part formed in the bearing housing through plastic flow can exhibit a high bonding strength between the bearing housing and the thrust bearing in the spindle motor without deteriorating the sealing ability of the spindle motor, due to a shearing force and a residual contact pressure of the covering part.

Spindle motor and manufacture thereof

A spindle motor comprises a housing including a through hole with a pair of apertures, one of the apertures being closed by a thrust plate and the other aperture being open; a bearing accommodated in the housing a rotating shaft inserted into the bearing a displacement restraining structure for restraining movement of the rotating shaft toward the open aperture by engaging the rotation shaft with the bearing a rotating member secured to the rotating shaft; and a motor generating electromagnetic function for rotating the rotating member. The through hole of the housing includes a large diameter portion A at the thrust plate side and a small diameter portion B at the open aperture side, and a stepped portion is formed at a transition portion between the large diameter portion A and the small diameter portion B. At least a portion of the bearing is located at the large diameter portion A side of the housing and engages with the stepped portion of the housing

Spindle motor

A conventional plain bearing, in which dynamic pressure is generated by means of lubricating oil, has been assembled in such a way that the whole bearing device is assembled and then the lubricating oil is poured in the interior. As a result, residual air bubbles are produced to cause lowering of the dynamic pressure. The present invention uses magnetic fluid as lubricating oil, and adopts, for enclosing the fluid, a method in which at the time of assembling a spindle motor, a permanent magnet is used, magnetic fluid of a specified amount is previously held in a bearing unit by the magnetic attraction force, and after the insertion of a shaft, the magnetic fluid is supplied into a narrow space of a bearing part by a capillary attraction.

Assembly method of motor using magnetic lubrication fluid

A cylindrical sintered material is placed in a cavity composed of die, a core disposed in the center of the die, and a pair of upper and lower punches provided within the die and compressed by the upper and lower punches. A gap is provided between an internal circumferential portion of the sintered material and an external circumferential portion of the core. Consequently, when the sintered material is compressed, plastic flow is produced at both ends of the sintered material so that an internal circumferential portions at corresponding portions protrude inward in a radius direction till the internal circumferential portions come into contact with the core, so that slide portions are formed.

Growing community of inventors

Ibaraki, Japan

Toshikazu Takehana