| 摘要 |
PURPOSE:To prevent elongation, slip and the like of a belt due to load fluctuations during coupling movement by performing a coupling operation in a coupling mechanism through a coil spring to absorb a shock. CONSTITUTION:A coil spring 13 mounted on the outer periphery of a load shaft 10, one end thereof being hooked on the shaft 10, the other end thereof being hooked on an armature 5 is adapted to have an urging force at the adsorption position of the armature 5, which is weaker than adsorption of an electromagnet and opposite to the adsorption so as to perform a coupling operation in a coupling mechanism. The electromagnet 2 is turned on electricity, which causes the armature 5 to be adsorbed to a rotating rotor 1 and start moving in a body. In such a transition stage, the armature 5 is adapted to start rotating in such a manner as to restore the spring 13 to be reduced-diameter coil. When the spring 13 is completely coiled round the shaft 10, power transmitted from the armature 5 is transmitted from a bent portion 15 of the spring 13 to the shaft 13. Thus, only static torque equal to return load of the spring 13 is gently worked on an inside bent portion 14 of the spring 13 engaged with a groove 11 of the shaft, and no inertial shock or the like is worked thereon. |
