Electronic torque transmission device without power battery

A thermal vehicle engine (10) is connected to road wheels (80), two electrical machines (20,30) and a mechanical assembly (40) by shafts (100,400,401,402). The electrical machines are connected by a linking unit (50) and electronic control unit (70) which ensure that power generated by one machine is immediately consumed by the other and that there is a response to the requirements of the traction chain. An Independent claim is made for a vehicle using the transmission system.