Hydrostatic transmission with after-coupled gearbox - has gear change valves operating according to differential speed of couplings, to ensure smooth gear change

摘要

The hydrostatic transmission is regulated according to the speed of the couplings that are changed over in the after-coupled gearbox when the gear is changed. A gear change valve, operated according to the differential speed of the coupling to be changed, controls a pair of adjustment pistons which regulate the hydrostatic transmission so as to give a smooth changeover. During the gear change, air is evacuated from the pressure chambers (4a, 5a) of the control cylinders (4, 5) through gear change valves (15, 19) simultaneously, the line (20) that leads from high-pressure circuit of the hydrostatic transmission (1) to the pressure chamber of the second control cylinder (5) is blocked.