| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power transmission device using a low strength material for an engagement member and cutting off transmission of power by rupture of the engagement part, when applied with a load exceeding a predetermined torque. <P>SOLUTION: This power transmission device 11 comprises a rotating shaft 19 having a rotating shaft body 21 and a male screw part 23 formed on the rotating shaft body 21; a cutoff part body 55; and a power cutoff member 53 having a tubular member 59 with a female screw part 57 screwed with the male screw part 23 and the engagement part 61 for engaging the tubular member 59 with the cutoff part body 55. The rotating shaft 19 comprises a step surface 25 facing an inner hub 45 secured to the power cutoff member 53. The inner hub 45 comprises an abutting surface 49 abutting on the step surface 25 of the rotating shaft body 21. A surface treatment to provide fine recesses and projections on the surface is applied to one or both of the abutting surface 49 and the step surface 25. <P>COPYRIGHT: (C)2008,JPO&INPIT |
