Drive unit

A drive unit for an electric vehicle, comprising:

• an electric motor for propulsion;
• and
• a cooling system,
• wherein the electric motor comprises a stator assembly and a rotor assembly,
• wherein the stator assembly comprises a stator housing, a stator core with grooves, and a winding assembly,
• wherein the winding assembly extends through the grooves,
• wherein the stator housing comprises a stator housing inlet and a stator housing outlet,
• wherein the grooves are fluidically connected to the stator housing inlet and with the stator housing outlet,
• wherein the cooling system comprises a first cooling circuit, a second cooling circuit, a third cooling circuit, and a pumping apparatus,
• wherein the first cooling circuit is connected to the stator housing inlet and to the stator housing outlet so as to enable a direct cooling of the winding assembly,
• wherein the first cooling circuit comprises an expansion tank assembly, the expansion tank assembly comprising an expansion tank, an expansion tank inlet, an expansion tank outlet, and a volume change assembly,
• wherein the expansion tank is connected to the first cooling circuit via the expansion tank inlet and the expansion tank outlet,
• wherein the volume change assembly has a first volume and is configured as a closed volume change assembly without fluidic connection to an outer environment of the drive unit,
• wherein the volume change assembly is configured to enable a change of the first volume and thus of a total volume of the first cooling circuit as a function of the pressure in the first cooling circuit such that, as the pressure in the first cooling circuit increases, the first volume is at least partially increased and, as the pressure in the first cooling circuit decreases, the first volume is at least partially reduced,
• wherein the volume change assembly comprises a displaceable element including a rod that is guided within a body of the volume change assembly,
• wherein the pumping apparatus comprises a first pump and a second pump,
• wherein the first pump is configured to convey a first coolant in the first cooling circuit,
• wherein the second pump is configured to convey a second coolant in the second cooling circuit,
• wherein the first cooling circuit comprises a first heat exchanger and the second cooling circuit comprises a second heat exchanger, and
• wherein the third cooling circuit is configured to cool the first heat exchanger and the second heat exchanger.