Infinitely variable gear transmission with automatic gear coupling

1. An infinitely variable gear transmission system comprising: a differential gear unit coupled to a power input from a vehicle; a hydraulic pump, a single stage planetary gear unit drivably intercoupling a sun gear with a first output shall of said differential gear unit, and a planet carrier, a hydraulic motor, with a second output shaft, said planetary gear unit including the sun gear, a ring gear, the planet carrier, and at least one planet gear mounted on said planet carrier to rotate with and relative to said planet carrier and meshed with the sun gear and the ring gear, wherein a hydraulic circuit comprising a bypass valve, a flow control valve with a variable orifice, hydraulically intercoupling the hydraulic pump coupled to the first output shaft of said differential gear unit, an automatic gear coupling for the first and second output shafts, a hand brake for the second output shaft for reversing the ring gear, and a microprocessor unit selectively controlling the resistance exerted by the fluid pressure on the said sun gear to control the speed of the ring gear of said planetary gear unit coupled to a drive shaft of the vehicle, to provide the desired speed for the vehicle.

2. The infinitely variable gear transmission system of claim 1 wherein said hydraulic circuit includes a hydraulic motor coupled to the planet carrier shaft, hydraulically intercoupling the hydraulic pump and said flow control valve with the variable orifice, to accelerate the ring gear connected to the vehicle.

3. The infinitely variable gear transmission of claim 1 comprises an automatic gear coupling to be actuated by said microprocessor to couple the sun gear and the planet carrier in order to maintain the speed of the sun gear, the planet carrier, and the ring gear at the same level during normal drive.

4. The infinitely variable gear transmission of claim 1 includes a manually operated hand brake coupled to the second output shaft of the differential gear unit to reduce the speed of the planet carrier in order to reverse the direction of rotation of the ring gear, and thus to provide reverse movement for the vehicle, and also to stop the vehicle quickly on an emergency.

5. The infinitely variable gear transmission system of claim 1 , where in said microprocessor control unit continuously monitors accelerator pedal position of the vehicle, engine speed of the vehicle, and the lubrication oil temperature of the vehicle, to reduce the speed of said vehicle in case of overloading.

6. The infinitely variable gear transmission system of claim 1 , where in said microprocessor control system sets the speed of the sun gear at constant level when the vehicle is idling in neutral and thus prevent the accidental movement of the vehicle in the reverse direction.

7. The infinitely variable gear transmission system of claim 1 , where in said microprocessor control system sets the functional speed of the sun gear at a higher level as desired by the microprocessor control unit to reduce the speed of ring gear to build up additional torque while the vehicle moves up on a gradient.

8. The automatic gear coupling of claim 3 includes a manual switch which can withhold the action of said automatic gear coupling, and retain the sun gear and the ring gear coupled through, to enable the vehicle to continue in the normal drive with out moving to the gear drive, to save fuel.

9. The infinitely variable gear transmission system of claim 1 wherein said hydraulic circuit includes a hydraulic motor coupled to the ring gear instead of the planet carrier, hydraulically intercoupling the hydraulic pump and said flow control valve with the variable orifice, to accelerate the ring gear connected to the vehicle.