Electrohydrostatic Actuator System with an Expansion Reservoir

Abstract

An electrohydrostatic actuator system comprising: a volume- and/or speed-variable hydraulic machine which is driven by an electric motor, for providing a volumetric flow of a hydraulic fluid; a differential cylinder with a piston side and a ring side; and at least one pretensioning source. The actuator system has a closed hydraulic circuit, wherein, during operation, the hydraulic fluid in the hydraulic circuit is pressurized by means of the hydraulic machine and/or the pretensioning source. Furthermore, according to the invention, the differential cylinder provides a power motion operating mode and a rapid motion operating mode. In order to balance a volume of the hydraulic fluid in the closed hydraulic circuit, according to the invention an expansion reservoir is connected to the piston side of the differential cylinder via a valve.

Dependencies are inferred from the claim text.