Ntn Corporation

Kabushiki Kaisha Act One

Kenichi Mitani

Masafumi Okuma

Fuminori Satoji

Isao Komori

Kazuo Okamura

Ryouichi Nakajima

Natsuhiko Mori

Nobuyoshi Yamashita

Toshiyuki Mizutani

Kiyoshi Ishii

Masumi Okajima

Junji Ichikawa

It is an object of the present invention to provide a bearing member having a highly accurate dynamic pressure generating portion stably at low cost. Dynamic pressure grooves () and () are formed as the dynamic pressure generating portions on an inner circumferential surface of the electroforming portion () by an electroforming process, and injection molding is performed by using a resin while inserting the electroforming portion (), thereby forming a bearing member (). A shaft member () is inserted into an inner circumference of the bearing member.

Fluid dynamic bearing device

Assembly precision in a motor is improved and greater cost reduction is achieved. A fluid dynamic bearing apparatuscomprising a housingand bearing sleeveas fixed-side members, a shaft memberas a rotational-side memberhaving a portionfor mounting a rotor magnet, and a disk hub, the shaft memberbeing supported by the bearing sleevein the radial direction in a non-contact manner by the hydrodynamic effect of a lubricating oil produced in a radial bearing gap between the inner circumferential surfaceof the bearing sleeveand the outer circumferential surfaceof the shaft member while the shaft memberis in rotation, the apparatuscomprising a disk hubwhich is fixed on the shaft memberand has a portionfor mounting the rotor magnet, and the disk hubbeing a molded resin article formed by insert-molding using the shaft memberas an insert piece.

Fluid dynamic bearing apparatus and a motor using the same

Assembly precision in a motor is improved and greater cost reduction is achieved. A fluid dynamic bearing apparatus includes a housing and bearing sleeve as fixed-side members, a shaft member as a rotational-side member having a portion for mounting a rotor magnet, and a disk hub. The shaft member is supported by the bearing sleeve in the radial direction in a non-contact manner by the hydrodynamic effect of a lubricating oil produced in a radial bearing gap between the inner circumferential surface of the bearing sleeve and the outer circumferential surfaceof the shaft member while the shaft member is in rotation. The apparatus includes a disk hub which is fixed on the shaft member and has a portion for mounting the rotor magnet, and the disk hub is a molded resin article formed by insert-molding using the shaft member as an insert piece.

The ferrule of the present invention comprises a ferrule main body including an insert pipe defining an outer circumferential surface of the ferrule main body and a molded plastic member disposed inside the insert pipe integrally therewith and having an optical fiber receiving bore in an axial center thereof; and a tubular base portion molded onto a rear end of the ferrule main body. Because the outer diameter of the ferrule main body is defined by the insert pipe, the rigidity, circularity and dimensional precision of the outer diameter can be improved. Because the base portion is molded separately from the ferrule main body, the manufacturing process can be simplified and the production cost can be reduced.

Ferrule and metallic die assembly for making the same

An insert pipe is fitted on an outer circumferential surface of a front end of a ferrule provided with a core wire receiving bore in an axial center thereof, and a small-diameter tubular portion is insert molded coaxially with the insert pipe around the core receiving bore adjacent to the front end, a thin-walled plastic portion being formed inside the small-diameter tubular portion. A plastic reservoir may be provided in a part of the plastic ferrule remote from the front end of the core wire receiving bore. The provision of the thin-walled plastic portion and/or the plastic reservoir prevents the tapering of the core wire receiving bore due to thermal shrinkage following the injection molding process.

Growing community of inventors

Tokyo, Japan

Kenichi Mitani