Koyo Seiko Company, Ltd.

Nippon Grease Co., Ltd.

Other

Jtekt Corporation

Hiroshi Komiya

Seiji Okamura

Hiroki Iwamatsu

Ryuji Nakata

Youzou Taniguchi

Toshihiro Kawaguchi

Masayuki Kitamura

Hiroyoshi Yasui

Teruo Yoshida

Atsushi Yao

Ken Adachi

Nao Ito

Toshikazu Kouno

Koji Yoshizaki

Noriko Suekuni

Toshitaro Oguchi

Bismuth dithiocarbamate (BiDTC) is added to a urea grease containing a lubricating base oil having a poly-&#x3b1;-olefin synthetic oil or a diphenyl ether synthetic oil and a diurea thickening agent, or a fluorine grease containing a lubricating base oil having fluorinated synthetic oil and a polytetrafluoroethylene thickening agent. By taking such constitution as described above, a surface film is formed on a surface of a raceway of any one of inner and outer rings or a surface of a rolling element of a bearing. Therefore, the rolling bearing in which a grease composition having the constitution is packed can maintain an excellent lubricity for a long period of time even under severe conditions such as a high rotation, a high temperature and a heavy load. Further, the grease composition for the rolling bearing is low in harmfulness to a human body and gives little load to the environment.

Grease composition for rolling bearing and rolling bearing using the same

A film composed of grease, or a film composed of a thickener for grease, is formed on a portion of the surface of each of components constituting a bearing, the portion being opposed to a polymeric lubricant, whereby sliding frictional resistance between the bearing components and the polymeric lubricant is reduced. In the formation of the film, the assembled bearing in which the film has not yet been formed is immersed into a liquid which is obtained by diluting the grease or the thickener for grease with a solvent, and the solvent is then dried, thereby to highly reproducibly form the film of uniform thickness. In an assembled double-row self-aligning roller bearing wherein an outer race is swingable in a direction perpendicular to the center axis of the bearing, raw materials of a polymeric lubricant are poured into and solidified in two regions of an annular space between the inner and outer races.

Polymeric lubricant packed bearing and method of producing the same

In a grease composition which essentially comprises a base oil and a thickener, a mixture of a urea compound and lithium soap is blended as the thickener. The content of the urea compound in the thickener is preferably set to 20 to 80 wt %. As the urea compound, an alkyl group- or cyclohexyl group-terminated diurea compound, or, particularly, a diurea compound in which the diisocyanate component is 4,4&prime;-diphenylmethane diisocyanate is preferably used. In a rolling bearing which is lubricated by the grease composition, the acoustic performance is largely improved by a synergistic action of the lithium soap and the urea compound, and simultaneously also the anti-fretting property is enhanced by an action of the urea compound.

Grease composition and rolling bearing lubricated by the grease composition

A rolling bearing has first and second races that define an annular space therebetween. A plurality of rolling elements roll on the races. The space is filled with a solid lubricant composition containing a resin polymer. The space is preferably sealed with a pair of sealing members which are interposed between the races and a region between the lubricant composition and the corresponding sealing member in the space is filled with grease.

Rolling bearing

The present invention is directed to a grease for a rolling bearing containing poly-&agr;-olefin synthetic oil or diphenyl ether synthetic oil, a diurea thickening agent, and an organic antimony compound or an organic molybdenum compound. The present invention is also directed to a rolling bearing in which the grease for a rolling bearing is sealed. The organic antimony compound or the organic molybdenum compound reacts with a metal composing inner and outer bearing rings and a rolling element to form a compound film contributing to the reduction of the force in the tangential direction on a raceway surface of the bearing rings and a surface of the rolling element, thereby preventing an excessively large force in the tangential direction under high-speed rotation. This enables to lengthen the life of the rolling bearing used under particularly severe conditions such as high temperature, high-speed rotation and high road.

Grease for rolling bearing and grease-sealed rolling bearing

There is provided is a conductive lubricant for a fluid dynamic bearing being able to ground static electricity occurring at the fluid dynamic bearing without impairing the performance of the fluid dynamic bearing. This conductive lubricant for a fluid dynamic bearing is provided by an ester base oil such as dioctyl sebacate that concurrently has heat resistance, a small quantity of evaporation, low cost and wettability to metal, which are necessary for a fluid dynamic bearing. The conductive lubricant contains 0.1 to 5 percent by weight of antistatic additive such as alkyl aryl sulfonate having an affinity for this ester base oil. Therefore, this antistatic additive imparts conductivity to the base oil, by which the static electricity occurring at the fluid dynamic bearing can be grounded without impairing the lubrication performance.

Conductive lubricant for fluid dynamic bearing

A rolling bearing has a pair of races, rolling elements and a cage. A region defined between the pair of races is filled with a solid lubricating composition. A film including a lubricating component is formed in a clearance between the cage and the rolling elements, whereby the solid lubricating composition is prevented from being interposed therebetween. The film including a lubricating component is formed prior to the process of filling the region with the lubricating composition to solidify the lubricating composition. It is preferable that the film including a lubricating component is formed on the respective surfaces in contact with the solid lubricating composition of the races, the rolling elements and the cage.

Rolling bearing and method of fabricating the same

The present invention provides a grease composition comprising a lubricating oil and a thickener, characterized in that the thickener is a diurea compound prepared by reacting a diisocyanate compound with cyclohexylamine and monoalkylphenylamine wherein the alkyl portion has 8 to 16 carbon atoms.

Growing community of inventors

Kashihara, Japan

Hiroshi Komiya