The hydraulic cylinder has a rod cavity, and the oil port of the accumulator is connected with the non rod cavity of the hydraulic cylinder through the hydraulic pump / motor and another hydraulic pump / motor to form a closed oil circuit. When the boom rises, the hydraulic oil is output from the rod cavity of the accumulator and the hydraulic cylinder to the non rod cavity of the hydraulic cylinder. On the contrary, the oil is output from the rodless cavity of the hydraulic cylinder, and part of the oil is recharged to the accumulator, and the other part is recharged to the rod cavity of the hydraulic cylinder, so that the oil in the rod cavity comes from the rodless cavity, that is, the boom flow regeneration.
The energy-saving system uses the accumulator pressure to balance part of the load weight. When the boom is lowered, the potential energy of the load part is stored in the accumulator in the form of pressure energy. When the boom is raised, the accumulator provides additional driving force for the motor hydraulic pump / motor shafting. The system controls the DC motor and realizes the variable speed and volume speed regulation of the hydraulic power system. The input power of the system is completely matched with the power required by the load, and there is no throttling loss and overflow loss.
