Gruppo motopropulsore ibrido per un veicolo, particolarmente per uno scooter

A hybrid drive assembly for a vehicle having at least one drive wheel,the drive assembly including an internal combustion engine; a transmission unit interposed between a drive shaft of the internal combustion engine and a propeller shaft connected angularly to the drive wheel, and in turn including a continuously variable transmission having a drive pulley connected angularly to the drive shaft and a driven pulley, and a centrifugal clutch having a hub connected to the driven pulley, and a driven bell connected to the propeller shaft; and an electric machine having a rotor integral with the bell of the centrifugal clutch. The drive assembly is controlled by a control unit, in response to a number of input signals (Ss, Sa, Sf), in a number of operating modes including an all-combustion propulsion mode, an all-electric propulsion mode, a first hybrid propulsion mode wherein the internal combustion engine and the electric machine are connected in series, and a second hybrid propulsion mode wherein the internal combustion engine and the electric machine are connected in parallel.