Infinitely variable split-torque compound power-shift transmission with range changes

摘要

The transmission comprises two component transmissions. One is an infinitely variable split-torque coupled gear with four shafts. One shaft represents the main input shaft and a second shaft is connected to the main input shaft via, for example, intermediate stages and an infinitely variable hydrostatic transmission. The two remaining shafts are coupling shafts, one of which runs progressively faster and the other progressively slower during adjustment of the hydrostatic transmission from one extreme transmission ratio to the other (and vice versa in the case of adjustment in the opposite direction), in which ratios both coupling shafts run in synchronism. The other component transmission is a shift transmission with one gear range and a plurality of range-change gears which act on the main output shaft. The two coupling shafts drive the gears of the gear range alternately. The shift transmission makes possible a large number of speeds with a relatively small number of gears and shift clutches. The gear changes take place in a load-free manner at synchronous speeds of rotation and without an interruption in the tractive effort. The compound power-shift transmission with a relatively small hydrostatic transmission acts like an infinitely variable transmission with a large adjustment range and good levels of efficiency. In a vehicle, it allows the internal combustion engine to be operated along the curve for minimum fuel consumption and thus permits fuel savings. In addition, it ensures a good acceleration behaviour.