Hitachi, Ltd.

Japan Servo Co.,ltd.

Hitachi Powdered Metals Co., Ltd.

Hitachi Electronic Devices Co., Ltd.

Takashi Kono

Hideaki Amano

Kenji Tomida

Tomoaki Inoue

Masaaki Nakano

Kenji Mori

Takashi Yoshida

Yasuhiro Yoshimura

Hiroshi Nishida

Katsutoshi Nii

Toshihiro Yamada

Takashi Yamaguchi

Yasuhiko Nonaka

Hiromu Hirai

Ryoji Okada

Satoru Yamaura

Toshiaki Makino

Yuichi Koizumi

Hideyuki Kimura

Marutomo Goto

Yuji Nishimura

Akio Takatsuka

Sachio Hatori

Toshio Matsushita

Yoshihiro Sato

Hiroshi Takakura

Makoto Kondoh

Seiichiro Terashima

Michihide Shibata

Takeru Sato

A recording disk apparatus comprises a clearance between a shaft and a thrust bearing portion tapered in a circumferential direction, a lubricant communication groove of a bearing covered by the shaft so that a lubricant on a radial bearing portion communicates with the lubricant on the thrust bearing portion through the lubricant communication groove, a lubricant circulating path which extends axially from the thrust bearing portion to the radial bearing portion to prevent the lubricant flowing out of the thrust bearing portion from returning directly to the thrust bearing portion without passing the radial bearing portion, and/or a clearance between a slide bearing and a magnetic fluid seal device substantially filled with a magnetic fluid lubricant.

Recording disk apparatus and rotational supporting structure therefor,

A bearing device where a sliding bearing rotatably supporting a shaft is molded with an inexpensive sintered material, three asymmetrical circular arc-shaped radial bearings are formed in the inner peripheral surface of the shaft, taper land-shaped thrust bearings are formed in the opposite end surfaces of the radial bearing surface, T-shaped bubble removing means which is constituted by axial and radial flow passages formed in the shaft opposed to the radial bearing is provided, and magnetic fluid is used as a lubricant. A magnetic disk unit using the bearing device is also disclosed.

Bearing device and spindle motor provided with the bearing device

Oil retaining bearing members 2a and 2b for supporting a rotative shaft 1 are arranged in a bearing housing 7 with an interval. The bearing housing 7 has a bottom portion, one end being opened and another end being closed. A porous spacer 3 for supplying a lubrication oil is closely inserted between the oil retaining bearings 2a and 2b. An oil thrower 8 is arranged at an upper portion of the bearing housing 7 and a thrust bearing 5 is arranged at a lower portion. The open end of the bearing housing 7 is arranged on the upper portion and the another end of the bearing housing 7 is arranged on the lower portion of the bearing housing 7, and state a lubrication oil 4a is enclosed in the housing to immerse a part of the porous spacer 3 to some degree. The pore diameter of the porous spacer 3 is larger than that of the oil retaining bearings 2a and 2b. By utilizing capillary tube action in by the porous spacer 3, the lubrication oil 4a is supplied to the oil retaining bearing 2a. Accordingly, an oil retaining bearing unit having an excellent performance and a superior mass productivity and a motor having a long service life and a high reliability using the oil retaining bearing unit can be provided.

Oil retaining bearing unit and motor having oil retaining bearing unit

A cathode ray tube has a cathode structure including a cathode body comprised of porous refractory metal impregnated with electron-emissive material, a metal cup for containing the cathode body therein, a metal sleeve having a closed end and mounting a heater therein, a cylindrical metal eyelet and a plurality of thin metal wires stretched across one end of the metal eyelet and suspending the metal cup and the metal sleeve concentrically with and in the cylindrical metal eyelet. The metal cup and the closed end of the metal sleeve are fixed with the plurality of thin metal wires interposed therebetween, and ends of the plurality of thin metal wires are welded to a metal flange formed at the one end of the metal eyelet. The metal cup can be welded to the closed end of the metal sleeve by an electron beam with the plurality of thin metal wires interposed therebetween. By virtue of providing the metal flange, the contact area for welding the metal wires is increased, thereby improving the welding strength and reliability.

Cathode structure for a cathode ray tube

Recording disk apparatus and rotational supporting structure therefor

A magnetic disk unit comprising a one-piece carriage structure having a small thermal off-tracking amount, with the carriage structure including a rotary shaft; guide arms integrally supported on a guide-arm retainer at their proximal ends and extending independently and parallely; bearing retainers formed on both ends of the guide-arm retainer; and bearings fixed on the bearing retainers rotatably connecting the guide-arm retainer to the rotary shaft. A center line in a direction of thickness of the outermost guide arm is located outside of that of the bearing in a direction of height thereof, and a concave portion is continuously formed on the bearing retainer. Thermal coefficients of expansion of the guide arms and the guide-arm retainer are substantially equal, with the carriage structure being fashioned of an alloy mainly containing Al and Si, eutectic crystal Si particles in the guide arm and/or the guide-arm retainer. The average value of the longest eutectic crystal Si particles therein is 1.6 .mu.m or less or the number of the eutectic crystal Si particles if 5.0 or more per 100 .mu.m.sup.2. In the carriage of manufacturing the carriage of the carriage structure is heated for five to fifteen hours at a temperature of 300.degree. to 500.degree. C. after die casting.

Magnetic disk unit and manufacturing method of carriage structure thereof

Growing community of inventors

Ibaraki, Japan

Takashi Kono