Actuating device, particularly for actuating locking differentials on vehicles

An actuating device, specifically to actuate locking differentials on vehicles, having an actuating shaft, a drive unit to drive the actuating shaft, where the drive unit comprises an armature core non-rotatably mounted on the actuating shaft and a commutator non-rotatably mounted on the actuating shaft, having an electromagnetic brake unit to brake and/or to hold the actuating shaft, where the brake unit includes a brake hub flange non-rotatably mounted on the armature, and having a single- or multi-piece housing tightly enclosing the drive unit and the brake unit, where the free end of the actuating shaft extends from the housing.