Hydraulic actuator for orthotics or prosthetics and orthopaedic arrangement

A hydraulic actuator for orthoses or prostheses, comprising a control element with a housing in which a cylinder is arranged, in which a piston is mounted movably and divides the cylinder into a flexion chamber and an extension chamber, wherein a fluidic connection is arranged between the flexion chamber and the extension chamber, a control valve is arranged in the fluidic connection for influencing an extension movement and a flexion movement respectively, wherein a motor-driven pump is arranged in the fluidic connection, wherein hydraulic fluid is conveyed from a chamber selected from the flexion chamber and the extension chamber to the motor-driven pump through the control valve in a suction-side connection line, and two pressure-side check valves arranged in a pressure-side connection line from the motor-driven pump to an unselected chamber of the flexion chamber and the extension chamber and blocks a backflow of a pumped medium from this chamber to the motor-driven pump counter to a delivery direction of the motor-driven pump, wherein the pressure-side connection line, with which the motor-driven pump is connected to the fluidic connection, opens out between the two pressure-side check valves which act in a same direction and are arranged in series.