Drive unit (I) comprises superposition device having a first input shaft to establish a drive connection with a primary drive source, a second input shaft, and an output shaft; and an electric motor as a secondary drive source having a rotor and a stator, ...

The adjuster has two control rings (23,26) centered on a common axis, one axially supported and the other axially movable, one rotationally fixed and the other rotatable. The rotatable ring is coupled to an electric motor (11); the axially adjustable ring ...