초록 ▼

The use of bismuth-compounds in an extreme pressure grease lubricant composition for rolling bearing applications can extend the useful service life of rolling bearings. The bismuth can be used as an additive, preferably an EP additive, or as a soap or non-soap thickener. The invention further relat

The use of bismuth-compounds in an extreme pressure grease lubricant composition for rolling bearing applications can extend the useful service life of rolling bearings. The bismuth can be used as an additive, preferably an EP additive, or as a soap or non-soap thickener. The invention further relates to a method for preparing an extreme pressure lubricant composition in which a bismuth containing soap or thickener is mixed with an oil and optionally one or more EP- or other additives.

대표청구항 ▼

[ What is claimed is:] [1.] A method for extending the service life of a rolling element bearing comprising:preparing a first extreme pressure grease lubricant composition comprising an effective service life extending amount of at least one bismuth-containing compound and being substantially free o

[ What is claimed is:] [1.] A method for extending the service life of a rolling element bearing comprising:preparing a first extreme pressure grease lubricant composition comprising an effective service life extending amount of at least one bismuth-containing compound and being substantially free of sulfur compounds and substantially free of compounds that provide or release free reactive sulfur under bearing operating conditions;identifying effective service lives of said rolling element bearing treated with said first extreme pressure grease lubricant composition and of said rolling element bearing treated with a second extreme pressure grease lubricant composition, identical to said first extreme pressure grease lubricant composition, except wherein said at least one bismuth-containing compound of said first extreme pressure grease lubricant composition is replaced in said second extreme pressure grease lubricant composition by a non-bismuth-containing compound; andtreating said rolling element bearing with said first extreme pressure grease lubricant composition for a period of time at least longer than the effective service life of said second extreme pressure grease lubricant composition,wherein said at least one bismuth-containing compound is an organobismuth compound suitable for use in a grease lubricant composition and is selected from the group consisting of compounds having the formula (R--CO.sub.2).sub.3 Bi, wherein R is a branched, straight or cyclic alkyl group with 1-30 carbon atoms or an aryl, alkaryl or aralkyl group with 6-20 carbon atoms.