Variable speed change gear

Variable speed change gear comprising:

• an input side rotator having an axis of rotation and arranged to be rotationally driven by an external driving force;
• an output side rotator arranged concentrically with said input side rotator;
• a main driving rotator arranged to turn on the axis of rotation of said input side rotator under the action of a rotational force of said input side rotator;
• a control shaft arranged to be driven by the external driving force;
• a worm wheel arranged to be driven by said input side rotator;
• an offset housing coupled to said worm gear, said worm wheel rotatable in accordance with the amount of rotation of said control shaft thereby causing said offset housing to be radially offset relative to said input side rotator;
• a plurality of movable blocks movable with said offset housing, each including a radially extending groove;
• a plurality of variable rings arranged on a predetermined circumference around the axis of rotation of said input side rotator, said driven rotators revolvable along said circumference under the action of a rotational force of said input side rotator, each of said variable rings having a rod engaged with a corresponding groove in one of said movable blocks, said rods being radially offset relative to grooves when said offset housing is moved to a radially offset position;
• an offset ring including an elliptical groove formed in the surface thereof, said movable blocks including pins for engaging in said elliptical groove, said movable blocks and said offset ring being arranged for correcting periodically varying angular velocities of said variable rings and for making the angular velocities of said variable rings substantially uniform within a predetermined phase range;
• a clutch cylinder having an inner peripheral surface positioned radially outwardly from a transmission member provided on each of said variable rings in a freely rocking manner, each of said transmission members serving to lock into an inner peripheral surface of said clutch cylinder of said output side rotator when the speed of revolution of said variable rings is higher than that of said output side rotator, said transmission member being slidable over said inner peripheral surface of said clutch cylinder when the speed of revolution of said variable rings is lower than that of said output side rotator to thereby permit the difference in speed of revolution between the variable rings and said output side rotator, said clutch cylinder being arranged for extracting from said variable rings only rotational forces having corrected angular velocities for transmission to said output side rotator.