The agricultural area requires precisely adhered to speeds, sometimes a very high torque, and of course, a high efficiency rate. All this cannot be offered either by a purely mechanical nor by a hydraulic system. If the flow-velocities in the hydraulics are kept low (hydro-statics), then the effeciency increases. The system explained here combines the possibility of high torque transfer with the advantages of a mechanical power transmission. It has however, taken quite some time to develop the suitable, swivelling hydro-statics.
Coming from the left of the engine, the torque is transferred to the planet-gear carrier on the right through a torsion damper. From there it divides the power through the ring-gear to the hydro-axial piston pump at the top (hydraulic drive) and further through the sun-wheel to the final drive below on the right. This is connected with an axial-piston motor (hydraulic output). There is a tube connecton between the hydro-pump and the hydro-motor. Click on the 'pulling off' button and you'll see that, in this case, only very little torque, at low RPMs is transferred via the mechanical section and a very high torque through the hydraulic section. This occurs through the infinitely variable incline of the axial pistons. The higher the demanded torque, the more the incline of the thrust-drive increases. To achieve a higher speed with less torque, the incline of the pump section is brought to the zero position. Through inclining the pump in the other direction, even infinitely variable changing to reverse gear can be realised. There are also hybrid systems in which, instead of a hydro-motor, an electric motor is installed. 11/10