Electro-hydrostatic drive system

An electro-hydrostatic drive system comprising:

• a hydraulic machine which is driven by an electric motor and has a variable volume and/or rotational speed, for providing a volumetric flow rate of a hydraulic fluid,
• a differential cylinder with a piston surface and with an annular surface;
• and
• at least one equalization container,
• wherein during operation, the drive system has a closed hydraulic circuit and has an overpressure relative to the environment by means of the hydraulic machine and/or a pretensioning source,
• the drive system provides a movement of the cylinder in a first direction by means of a volumetric flow of the hydraulic machine and a volumetric flow from the equalization container, and
• provides a movement in a second direction, by means of a volumetric flow of the hydraulic machine and a volumetric flow into the equalization container, and the operating modes of a power operating mode or speed operating mode are provided with the differential cylinder;
• and
• wherein both sides of the hydraulic machine are connected with the pretensioning source for transmitting a pretensioning in the hydraulic fluid of the closed hydraulic circuit, and the piston chamber of the differential cylinder is connected with the hydraulic machine via a conduit and with the equalization container via additional conduits.