Hydrostatic/mechanical power-shift transmission with a continuously variable effect and with toothed selector clutches for shifts proprietary to gear changes and multi-plate clutches for the gear changes

摘要

The transmission consists of a four-shaft planetary gear mechanism, a continuously variable hydrostatic transmission, rear-mounted gear stages and selector clutches. The hydrostatic transmission includes two positive displacement machines. In the planetary mechanism, one shaft forms the input shaft, to which one positive displacement machine is connected. A second shaft of the planetary mechanism is connected to the other positive displacement machine. The third and fourth shafts of the planetary mechanism are coupler shafts, the speeds of which are infinitely variable and which, when rear-mounted stages are connected to the output shaft, form gears, a gear change being associated with a change of the coupler shafts. In the extreme positions of the hydrostatic transmission, selector clutches effect the gear changes at synchronous speeds of rotation, in a manner free from load and without interruption of the tractive effort, and do this without a jerk, i.e. provide a very smooth gear change. In addition, such transmissions have good efficiencies and a wide transmission-ratio adjustment range. They are therefore advantageously suitable for motor vehicles.