Abstract: A cooling system for a drive device with several electric machines, the cooling system including a hydraulic circuit for a coolant including a cooling part in a gearbox of the drive device for cooling the gearbox, and an air/coolant heat exchanger including cooling walls forming channels for circulating coolant for the cooling thereof, an air cooling circuit including a plurality of fans, rotationally coupled to the gearbox, a cooling part between the cooling walls of the air/liquid heat exchanger, wherein the air sucked in and propelled by the fans circulates by sweeping over the cooling walls in order to cool them.