| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving shaft capable of preventing occurrence of rattling, seizure and the like caused by abrasion, by keeping good sliding of contact surfaces for a long period when grease shortage has occurred, in comparison with a case where the driving shaft is coated with a resin film.SOLUTION: In the driving shaft 1, the surfaces of the keys 21 of a male spline part 22, which include contact surfaces 21a as power transmission surfaces for transmitting power to the another, of the male spline shaft 2 among the male spline shaft 2 and a female spline shaft 3 are coated with a continuous diamond-like carbon coating (6) having a Vickers hardness Hv of 1,000 or higher and a friction coefficient μ of 0.25 or less after a silicon coating or a chromium coating is formed on the metal base of the surfaces. |
