Lubricating oil composition, and precision reduction gear using same
AssigneeIdemitsu Kosan Co., Ltd.
InventorTakuya Ono
Life of this patent
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Abstract
Provided are a lubricating oil composition containing a base oil and a specific thiophosphate compound (A) and not substantially containing a molybdenum-based, and a precision reduction gear using the lubricating oil composition. The lubricating oil composition and the precision reduction gear using it exhibit excellent wear resistance and can prevent sludge generation in a broad range of contact pressures ranging from high to low.
Claims12
A lubricating oil composition, comprising, based on the total amount of the lubricating oil composition:
- a base oil;
- from 0.1% by mass or more to 1.0% by mass or less of a thiophosphate compound (A) of formula (I):
- wherein R1, R2 and R3 each independently represent an aryl group having 6 to 12 ring carbon atoms, and the aryl group may be substituted with an alkyl group having 1 to 3 carbon atoms;
- and
- from 0.1% by mass or more to 1.5% by mass or less of a phosphate compound (B) not comprising a sulfur atom, wherein the compound (B) is not an amine salt of a phosphate compound not comprising a sulfur atom,
- wherein the lubricating oil composition does not substantially comprise a molybdenum-based compound, and
- wherein the molybdenum atom-equivalent content of the molybdenum-based compound is less than 100 ppm by mass based on the total amount of the lubricating oil composition.
A method for producing a lubricating oil composition, the method comprising blending a base oil, a thiophosphate compound (A) of formula (I), and a phosphate compound (B) not comprising a sulfur atom, but not comprising blending a molybdenum-based compound:
- to obtain the lubricating oil composition,
- wherein, in formula (I), R1, R2 and R3 each independently represent an aryl group having 6 to 12 ring carbon atoms, and the aryl group may be substituted with an alkyl group having 1 to 3 carbon atoms,
- wherein the molybdenum atom-equivalent content of the molybdenum-based compound is less than 100 ppm by mass based on the total amount of the lubricating oil composition, and
- wherein the content of the thiophosphate compound (A) is, based on the total amount of the lubricating oil composition, 0.1% by mass or more and 1.0% by mass or less,
- wherein the content of the phosphate compound (B) is, based on the total amount of the lubricating oil composition, 0.1% by mass or more and 1.5% by mass or less, and
- wherein the compound (B) is not an amine salt of a phosphate compound not comprising a sulfur atom.
Dependencies are inferred from the claim text.