A hydrostatic actuator of this type is known from German Patent No. 197 00 935 A1. In accordance with this document, a piston of a master cylinder is driven by an electric motor and the rotary movement of the electric motor is converted into an axial movement by a gearing mechanism in the form of a worm drive. The piston is driven by an eccentric pin arranged on the worm gear.
In addition, European Patent No. 0 320 621 A1 discloses a planetary rolling-contact gear system that includes a threaded spindle, a sleeve arranged coaxially with the threaded spindle, and planetary gears rolling off between the two. The planetary gearing mechanism is driven to rotate by an electric motor and converts a fast rotary movement into a slower axial movement.
Thus, there is a long-felt need for a hydrostatic actuator that is preferably used in a motor vehicle and has an increased efficiency, reduced required installation space, and increased operating pressure of the master cylinder.