Minebea Company, Limited

Minebea Kabushiki-kaisha

Shigenori Hoya

Sumio Sato

Yutaka Daikuhara

Takuya Yamamoto

Hideki Matsuoka

Takaaki Tsuda

Tokushichi Furuta

The churning type of grease of a viscosity of 15&#x2013;20 mm/s and a worked penetration of 200&#x2dc;230 is disposed at the rolling surface of the race portions and the channeling type of grease of 25&#x2dc;35 mm/s and a worked penetration of 240&#x2dc;270 is disposed at the retainer. By constituting as such, at rotation of the ball bearing, maintaining the lubricant oil film in the bearing the lubrication can be continued, and at non-rotation of the ball bearing the lubricant oil film is protected by the grease to prevent fretting.

Ball bearing and lubricating method thereof

A retainer for a ball bearing being characterized in that each pocket includes upper halves following the entrance, a pair of lower halves following the upper halves, and a bottom portion disposed between lower halves, wherein an inner peripheral surface of each upper half presents a curved surface of a radius of curvature slightly larger than that of the ball to be retained therein in both peripheral and width directions of the pocket, an inner peripheral surface of each lower half descending inwardly, the inner peripheral surface of each lower half and an inner surface of the bottom portion each presents a configuration which has a shape of curved surface in the width direction of the pocket and of a straight shape in the peripheral direction of the pocket so as to contact tangentially with the ball so as to contact tangentially with the ball to be retained.

Retainer for ball bearing, and ball bearing including the same

Strength and rigidity are provided to a retainer so as to prevent the retainer from being deformed by force and sliding friction generated by rolling elements thereby preventing occurrence of retainer noise of a rolling bearing and aggravation of NRRO. A retainer is entirely formed of synthetic resin, and a highly elastic synthetic resin is used for the claws which are required to be highly elastic. A part below a boundary L of a body portion is formed of resin with sufficient strength and rigidity to prevent deformation due to force and sliding friction of rolling elements, thus preventing decline in strength of the retainer as a whole which may occur because of the use of resin with high elasticity for the claws. The strength of the retainer as a whole is fully ensured by the body portion, thus improving various functions, contributed by the rolling bearing.

Retainer for rolling bearing

The present invention provides a rolling bearing that prevents retainer noise and NRRO deterioration thereof by imparting strength and rigidity to a retainer so as to prevent it from being deformed by force from rolling elements and sliding friction. An annular plate is connected to a retainer by bosses. Due to the rigidity of the annular plate, the strength and rigidity of the retainer can be improved. Additionally, since the bosses are fixed to grease reservoirs arranged at an equal spacing therebetween on the circumference of the retainer, the strength and rigidity of the retainer can be equally improved over the entire circumference thereof.

Rolling bearing with reinforcing member

A bearing and a method for fabricating a bearing. The bearing is intended to be used in office automation equipment and the like is improved in impact resistance and load capacity. Its rotational accuracy will not deteriorate in long-term use and its quietness can be maintained over a long period of time. The bearing is an anti-friction bearing located between portions supporting a load and in relative motion to each other. The anti-friction bearing has an outer ring of 30 mm or less in diameter, in which high carbon chromium bearing steel constituting the anti-friction bearing includes the following compositions: C of 0.90-1.30 wt %, Si of 0.40-1.20 wt %, Mn of 0.90-1.0 wt %, and Cr of 0.90-1.70 wt %. After quenching, the tempering temperature used for this bearing is maintained in the range of 170&deg; C. and 250&deg; C. so that the amount of retained austenite in the surface layer after heat treatment is stabilized at 6 by volume or less.

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Kitasaku-gun, Japan

Shigenori Hoya