Hydraulic system of industrial truck e.g. battery-electrically operated industrial truck, has bypass drain line which is guided from lifting device to container, for arrangement of lowering valve

摘要

The hydraulic system (1) has hydraulic displacement unit which is in connection with electrical machine and provided in pump drive, for separate or joint supply of lifting device (2) and load (4,4a,5). The displacement unit is used as the motor in lowering operation of the lifting device for energy recovery, and the associated electric machine (9,10) is used as a generator. A bypass drain line (40) is guided from lifting device to container (12), for arrangement of lowering valve (41).