Abstract: A regulating device for the continuous phase-shifting of the angle of rotation of a camshaft controlling the gas exchange valves of an internal combustion engine with respect to a driving element, notably a chain or belt, includes an electric regulating motor coupled to a reduction gearbox with three inputs/outputs comprising an external ring gear, an input element and an outer disc, the external ring gear being carried by the drive element, the outfit disc being secured to the camshaft. This device includes a single shaft inside the stator of the electric motor, the single shaft supporting the input element of the reduction gearbox and the rotor of the electric motor.