Abstract: An infinitely variable gear transmission system for vehicles includes a differential gear unit for input, a planetary gear unit, an automatic gear coupling, a hydraulic pump and a hydraulic motor, the hydraulic pump rotating with the first output shaft of the differential gear unit and one of the three gear elements of the planetary gear unit, the hydraulic motor rotating with one of the two remaining gear elements, the automatic gear coupling for coupling the two output shafts of the differential gear unit, and a Microprocessor unit to selectively control the fluid pressure in the hydraulic circuit by adjusting the flow control valve, and control the speed of the third gear element connected to the vehicle.

Abstract: An infinitely variable gear transmission system for vehicles includes a differential gear unit for input, a planetary gear unit, a hydraulic pump and a hydraulic motor, the hydraulic pump rotating with the first output shaft of the differential gear unit and one of the three gear, elements of the planetary gear unit, the hydraulic motor rotating with the second gear element and a control unit to selectively control the fluid pressure in the hydraulic circuit by adjusting the flow control valve, and control the speed of the third gear element in clockwise and anticlockwise direction. In another embodiment the prime mover is directly connected to one of the three gear elements of the planetary gear unit, and also connected to the second gear element through a conventional speed variator and controls the speed of the third gear element by automatically adjusting the speed variator.