Actuator device

An actuator device for linear movement of an actuator output element along a movement axis having a first drive unit and a second drive unit, wherein the first drive unit has a first piston chamber and a first piston mounted so as to be linearly displaceable therein and also first hydraulic means for displacing the first piston in the first piston chamber, and wherein the second drive unit has the actuator output element which is linearly movable along the movement axis and which can be coupled to the first piston of the first drive unit for thrust, so that by movement of the first piston in an outward direction the actuator output element is likewise moved in the outward direction, wherein the second drive unit has a second piston chamber joined to the first piston chamber for conjoint movement therewith and a second piston mounted so as to be linearly displaceable in the second piston chamber and also second hydraulic or pneumatic means for displacing the second piston in the second piston chamber, the second piston being joined to the actuator output element for conjoint movement therewith, so that by movement of the second piston in the outward direction the actuator output element is movable out of the second piston chamber and by movement of the second piston in an inward direction opposite to the outward direction the actuator output element is movable into the second piston chamber, wherein the actuator device has a position-measuring device for detecting the positions of the first piston and the second piston relative to a reference position that is fixed with respect to the device for a position-controlled movement of the actuator output element.