| 摘要 |
PROBLEM TO BE SOLVED: To make change of the coefficient of friction between a ball screw and a bearing very little when the surface of the ball screw is exposed to halogen based gas for a long time, by covering the surface of the ball screw with a DLC film. SOLUTION: Material of a ball screw 32 is stainless (SUS 440C). A diamond like carbon film (DLC film) is formed 1 μm thick on the surface of the ball screw 32. Mean roughness of the DLC film is 5-30 Å, so that smoothness is high and the coefficient of friction is small. The DLC film uniformly covers the whole surface of the ball screw 32. Since Vickers hardness of the DLC film on the stainless steel, SUS 440C is high, wearing which is caused by rubbing against a bearing 33 hardly progresses, and stable sliding property can be maintained for a long time without using conventional grease. The DLC film has high anticorrosion characteristic to halogen based gas. |
