Minebea Company, Limited

Minebea Kabushiki-kaisha

Hideki Matsuoka

Hiroyuki Yajima

Shigenori Hoya

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 double row bearing includes a shaft and an inner ring mounted on the shaft. A preloading collar is fixedly mounted on the shaft and an elastic member is disposed between the inner ring and the preloading collar so that the preloading collar applies a predetermined preload to the inner ring through the elastic member. This structure compensates the reduction of the preload due to the temperature rise of the bearing and axial displacement of the inner ring of the bearing.

Double row bearing

An anti-frictional bearing which is reduced in its asynchronous rotational run out so that the cumbersome analyzing operation of the raceway surface and selecting operation of inner and/or outer races are not required. The bearing will contribute for the high packaging density and high speed operation of the hard disk device. An anti-frictional bearing including an inner raceway is formed on an outer peripheral surface of an inner race 1, an outer raceway 2 formed on an inner peripheral surface of an outer race 2, and a plurality of rotating bodies 3 interposed between the raceways and retained by retainers 4 in a predetermined distance with each other, wherein an out of roundness of a raceway surface 1 , 2 of at least one of said inner and outer races 1, 2 is equal to or less than 0.05 &mgr;m.

Anti-friction bearing and a motor including such a bearing

A roller bearing retainer comprising a substantially ring-shaped member having a plurality of ball pockets formed thereon to hold rolling members. Each ball pocket has a flat portion formed at its bottom portion and an opening portion extending from the flat portion of the retainer's ball pockets for receiving a rolling member. Each rolling member is held by a ball pocket having the flat portion whereby movement of the rolling member is suppressed. At the same time, a sufficient gap may be formed between the rolling member and a concave surface other than the flat portion. Thus, lubrication oil may readily be placed into the gap.

Growing community of inventors

Nagano-ken, Japan

Hideki Matsuoka