Driving device for automatically exerting a variable torque on an output shaft that rotates at a constant speed

A driving device, comprising:

• a power supply unit that outputs a constant power;
• and
• a torque converter, having;
• a flywheel;
• an input shaft;
• a first variable-diameter pulley mounted on said input shaft, and having first and second half portions, said second half portion having a control unit that causes said second half portion to move away from said first half portion when a rotational speed of said first variable-diameter pulley increases, thereby decreasing an effective diameter of said first variable-diameter pulley, and causing said second half portion to move toward said first half portion when a rotational speed of said first variable-diameter pulley decreases, thereby increasing the effective diameter of said first variable-diameter pulley;
• an output shaft;
• a second variable-diameter pulley mounted on said output shaft, and having third and fourth half portions that are movable toward and away from one another to respectively increase and decrease an effective diameter of said second variable-diameter pulley;
• a belt member disposed on and interconnecting said first and second variable-diameter pulleys, wherein when said first and second half portions of said first variable-diameter pulley move away from one another, said third and fourth half portions of said second variable-diameter pulley move toward one another, and when said first and second half portions move toward one another, said third and fourth half portions move away from one another, thereby maintaining said belt member under tension;
• and
• a gear train connected to said power supply unit and interconnecting said flywheel and said input shaft in order to respectively transmit a first portion of the power to said flywheel and a second portion of the power to said input shaft, said belt member transmitting the second portion of the power from said input shaft to said output shaft by way of said first and second variable-diameter pulleys, the second portion of the power exerting a torque on said input and output shafts to cause said input and output shafts to rotate at respective predetermined rotational speeds,
• whereby when a torque exerted on said output shaft by a load is increased, the rotational speed of said input shaft correspondingly decreases so that said second half portion of said first variable-diameter pulley automatically moves toward said first half portion of said first variable-diameter pulley by means of said control unit, and a rotational speed of said flywheel decreases to transmit power to said output shaft;
• and
• when a torque exerted on said output shaft by the load is decreased, the rotational speed of said input shaft correspondingly increases, so that said second half portion of said first variable-diameter pulley automatically moves away from said first half portion of said first variable-diameter pulley by means of said control unit, and the rotational speed of said flywheel increases to receive power from said output shaft;
• whereby the predetermined rotational speed of said output shaft is maintained constant without increasing or decreasing the power from said power supply unit.