Grease compostion for automobile electrical equipment auxiliary device and prelubricated rolling using the grease composition

Abstract

To provide a grease composition for auxiliary machinery of automobile electrical component containing an aromatic ester oil-containing base oil having a specific diurea compound as a thickener blended therewith and a rolling bearing having the foregoing grease composition packed therein. The foregoing grease composition and rolling bearing do not generate abnormal noises even at an extremely low temperature of −40° C., have excellent seizure resistance even under a high temperature closed to 180° C., have excellent rust preventing performance, and are suitable especially for electrical parts and auxiliary machineries of engines, etc.

Description

TECHNICAL FIELD [0001] The present invention relates to a grease composition which is used especially under severe conditions of high temperature, high speed, high load and vibration in automobile electrical parts or auxiliary machineries of engines such as alternators, intermediate pulleys, and electromagnetic clutches for car air conditioners and further which is used for parts required to have fluidity at an extremely low temperature of −40° C., and to a rolling bearing having the foregoing grease composition packed therein. BACKGROUND ART [0002] In automobiles, by the spread of FF (front engine front drive) vehicles aiming at miniaturization and lightening and the demands of enlargement of an accommodation space, a reduction of the engine room space is unavoidable, miniaturization and lightening of the above-enumerated electrical parts and auxiliary machineries of engines are further being advanced, and respective parts to be integrated thereinto are required to have high perfor...

AI Technical Summary

Benefits of technology

[0006] In order to solve the foregoing problems, the present inventors made extensive and intensive investigations. As a result, it has been found that among diurea compounds, those having an alicyclic hydrocarbon group, when combined with a base oil containing an aromatic ester oil, exhibit an excellent lubricating performance over a wide temperature range of from an extremely low temperature to a high temperature, do not generate abnormal noises at a low temperature, and can improve greatly a seizure performance of a bearing, leading to accomplishment of the invention.

[0008] Also, the invention provides the foregoing grease composition for auxiliary machinery of automobile electrical component, which is characterized by containing at least one member of carbon black and carbon nano tube as a conductive powder for the purpose of imparting conductivity. Further, it is preferable that two or more members selected from rust preventives made of a carboxylic acid or a carboxylate, ester based rust preventives, and amine based rust preventives are contained as a rust preventive in an amount of from 0.2 to 10% by mass in total and from 0.1 to 9.9% by mass singly based on the whole amount of the grease composition, whereby sufficient rust preventing properties are imparted. Also, such rust preventives are free from adverse influences against the environment.

Problems solved by technology

However, a lowering of the output due to the miniaturization is inevitable.

However, greases which can fully meet these diverse requirements inclusive of the above-enumerated greases have not been obtained yet.

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