The present invention relates to a system wherein a pair of relatively movable, facing DLC contact surfaces at least one of which is coated with a DLC film, are further lowered in friction, and the low friction property is stably maintained. The present invention also relates to a lubricant for the system, and a lubricating method. The lubricant for the system having the DLC contact surfaces contains lubricant base oil (A) mainly composed of base oil (X), and sulfur-containing molybdenum complex (B). The base oil (X) is at least one of hydrocracked mineral oils, wax-isomerized mineral oils, and poly-α-olefin base oils, and has a kinematic viscosity of 2 to 20 mm2/s at 100 °C, a total aromatic content of not higher than 5 mass%, and a total sulfur content of not higher than 0.005 mass%.
本发明涉及一种系统,在该系统中,一对相对可移动、面对面的 DLC 接触表面(其中至少一个表面涂有 DLC 薄膜)可进一步降低摩擦,并稳定地保持低摩擦特性。本发明还涉及一种用于该系统的润滑剂和一种润滑方法。具有 DLC 接触表面的系统润滑剂包含主要由基础油 (X) 和含
硫钼络合物 (B) 组成的润滑基础油 (A)。基础油 (X) 至少是加氢裂化矿物油、蜡异构化矿物油和聚α-烯烃基础油中的一种,在 100 °C 时的运动粘度为 2 至 20 mm2/s,总
芳烃含量不高于 5 质量%,总
硫含量不高于 0.005 质量%。