Grease composition for rolling bearing
AssigneeNsk Ltd.
InventorsKenichi Iso, Atushi Yokouchi, Hideki Koizumi, Michiharu Naka
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Abstract
The present invention provides a grease composition which is excellent in peel resistance, not to mention lubricity, as compared with the prior art products. A novel grease composition for rolling bearing is provided, comprising a base oil, an extender, an inorganic compound-based filler having an average particle diameter of not more than 2 μm and zinc dithiocarbamate.
Claims15
A grease composition for a rolling bearing used in an engine auxiliary machinery, comprising a base oil, an extender, an inorganic compound-based filler and zinc dithiocarbamate, wherein said inorganic compound-based filler is spherical, has an average particle diameter of not more than 2 μm and comprises at least one particulate material selected from the group consisting of Al2O3, MgO, TiO2 and diamond;
- the content of said inorganic compound-based filler is from 0.001% to 10% by weight based on the total weight of the composition;
- said zinc dithiocarbamate is a compound represented by the following formula (1):
- wherein R1 to R4 each represents a C1-18 hydrocarbon group, and is present in a content of from 0.05 to 10% by weight based on the total weight of the composition;
- and said extender is a diurea compound represented by the following formulae (2) to (4):
- wherein R5 represents C6-12 aromatic ring-containing hydrocarbon group;
- R6 represents a C6-15 divalent aromatic ring-containing hydrocarbon group;
- and R7 represents a cyclohexyl group or C7-12 alkylcyclohexyl group, and the content of said diurea compound is from 9 to 38% by weight based on the total weight of the composition.
A method for greasing a roller bearing, comprising the steps of:
- applying a grease composition to the roller bearing, wherein the greasing composition comprises a base oil, an extender, an inorganic compound-based filler and zinc dithiocarbamate, wherein said inorganic compound-based filler is spherical, has an average particle diameter of not more than 2 μm and comprises at least one particulate material selected from the group consisting of Al2O3,MgO, TiO2 and diamond;
- the content of said inorganic compound-based filler is from 0.001% to 10% by weight based on the total weight of the composition;
- said zinc dithiocarbamate is a compound represented by the following formula (1):
- wherein R1 to R4 each represents a C1-18 hydrocarbon group, and is present in a content of from 0.05 to 10% by weight based on the total weight of the composition;
- and said extender is a diurea compound represented by the following formulae (2) to (4):
- wherein R5 represents C6-12 aromatic ring-containing hydrocarbon group;
- R6 represents a C6-15 divalent aromatic ring-containing hydrocarbon group;
- and R7 represents a cyclohexyl group or C7-12 alkylcyclohexyl group, and the content of said diurea compound is from 9 to 38% by weight based on the total weight of the composition.
Dependencies are inferred from the claim text.