Hydraulic shaft with energy storage feature

A closed-circuit, self-contained hydraulic shaft includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that a cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic shaft includes a main accumulator connected to the pump via a first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic shaft is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator. 一种闭合回路的独立液压轴，包括电动马达、被构造成连接到负载的液压缸和由电动马达驱动以通过回路泵送液压流体的主泵。泵的压力连接件连接到缸的相应腔室，使得缸杆被构造成根据液压流体通过主泵的流动方向延伸和缩回。液压轴包括经由第一控制阀连接到泵的主累积器、经由第二控制阀连接到泵的储能累积器和供给泵。液压轴可在第一