LUBRICATING OIL COMPOSITION, AND SLIDING MECHANISM USING LUBRICATING OIL COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a lubricating oil composition exhibiting an extremely low friction coefficient when used as the lubricating oil for a low-friction sliding material, and to provide a sliding mechanism having excellent low friction properties by combining the lubricating oil composition with a sliding mechanism having a film of a specific low-friction sliding material on a sliding surface.SOLUTION: A lubricating oil composition used for a low-friction sliding material containing in a lubricant base oil, based on the total amount of the composition, (A) 0.005 mass% to 0.12 mass% of organic zinc dithiophosphate in phosphorus concentration equivalent, (B) 0.05 mass% to 5 mass% of an amine-based friction-reducing agent, and (C) 0.05 mass% to 0.5 mass% of an alkaline-earth metal salicylate-based cleaning agent and/or an alkaline-earth metal sulfonate-based cleaning agent in alkaline-earth metal concentration equivalent is characterized by containing 0.005 mass% to 0.05 mass% of primary dialkyl zinc dithiophosphate in phosphorous concentration equivalent in the component (A). There is also provided a sliding mechanism obtained by interposing the lubricating oil composition between mutually sliding surfaces of two sliding members, and having at least one sliding surface of the two sliding members having a DLC film containing hydrogen in the amount of 5 atom% to 50 atom% formed thereon.