| 摘要 |
PURPOSE:To reduce the axial space occupied by a belt pulley, by employing such an arrangement that the belt winding diameter can be varied without changing the width of the belt pulley. CONSTITUTION:Outer disks 13, 13' of a crank shaft 2 are turned with increasing of the speed of rotation of the crank shaft 2 against the force of a spring 20, and rotation of the outer disks 13, 13' precede rotation of inner disks 11, 11'. By the relative circumferential shifting of the inner and outer disks, the points of intersection of urging grooves 18, 18' formed in the inner disks 11, 11' and guide grooves 19, 19' formed in the outer disks 13, 13' are shifted gradually from the inner end to the outer end, and block members 21 are moved toward the outer circumference of the inner and outer disks 11, 11' and 13, 13' until the above two grooves intersect with each other at the outer end, so that the belt winding diameter of a belt pulley 9 is increased. As to a driven pulley, on the other hand, the belt winding diameter is decreased since the block members are moved toward the central part of the two disks. |
