The present invention is a rotary actuator having segments, which are spaced apart and are connected by means of at least one support structure, and at least one actuator for exerting forces, characterized in that the support structure is substantially rotationally symmetrical about an axis and is composed of elements which are not oriented parallel to the axis or which are twisted through an angle in relation to the axis, and the elements can be changed by rotation about the axis and the actuator can exert forces to at least one of the segments and the support structure in the direction of the axis.