| 摘要 |
PURPOSE:To facilitate the adjustment of rotational frequency by selectively operating two electromagnetic clutches according to the running condition to rotate integrally input and output pulleys when the rotational frequency of an engine is less than a predetermined one while rotating the output pulley through a planet gear device when it is higher than the predetermined one. CONSTITUTION:When the rotational frequency of an engine is less than a predetermined value (about 1500rpm), only a second electromagnetic clutch 62 is turned in to press an armature 58 mounted to a second puller 50 on a first pulley 44 against a leaf spring 56 by the magnetic force of electromagnetic coil 24. Thus, the first and second pulleys 44, 50 can be rotated integrally. On the other hand, when the rotational frequency of engine is higher than the predetermined value, only the first electromagnetic clutch 33 is turned in to press an armature 32 mounted to a blade section 28 on a body 10 against a leaf spring 30 by the magnetic force of an electromagnetic coil 22 and fix a rotary shaft 20 to a body 10. Thus, the rotation of second pulley 52 is decelerated by a planet gear device (34, 36, 54) and then transmitted to the first pulley 44. |
