US Patent 7703283 Automotive air blowers

An automotive air blower, in particular a supercharger, comprises an air pump, such as an air impeller (2) connected to the output shaft (4) of a transmission system, the input shaft of which is connected, in use, to the engine of a motor vehicle. The input and output shafts (6, 4) are connected to respective branches of a three-branch epicyclic differential gearset. The third branch of the gearset and the input shaft (6) are connected to the rotor (20, 22) of respective electrical machines, the electrical connections of the stators (24, 26) of which machines are connected together via a controller (27) arranged to control the flow of electric power between them.