Patent ID: 7315099

Claim:
An electric drive unit for a motor vehicle, comprising: (a) an electric motor comprising a non-rotating stator, a rotatable rotor, and a motor enclosure; (b) a planetary gear system comprising a rotatable input connected to the rotor for torque transmission, a rotatable output, and a gear system enclosure; (c) a rotatable wheel carrier that is connected to the output of the planetary gear system for torque transmission from the planetary gear system to the wheel carrier; (d) a stub axle component supporting the electric motor, the planetary gear system and the wheel carrier, the stub axle component comprising a cantilever member including: a mounting portion for mounting the drive unit to the motor vehicle, the mounting portion defining a first, supported end of the stub axle component, and a non-rotating stub axle portion extending from the mounting portion of the stub axle component into an interior region of the electric motor, an interior region of the planetary gear system, and an interior region of the wheel carrier, the non-rotating stub axle portion defining a second, unsupported end of the stub axle component; (e) wherein the rotor of the electric motor, the input of the planetary gear system, the output of the planetary gear system, and the wheel carrier are rotatably supported by the non-rotating stub axle portion; (f) a partition wall between the electric motor and the planetary gear system, said partition wall being part of both the motor enclosure and the gear system enclosure; (g) a liquid cooling system providing cooling of the stator, wherein the stator comprises an outer circumference, and the liquid cooling system comprises a plurality of axially-oriented coolant distributing tubes arranged around the outer circumference of the stator; (h) an air cooling system operating by air circulating inside the motor enclosure and not being in flow connection with ambient air, said circulating air providing cooling of the rotor and being in contact with the partition wall; and (i) an air/liquid heat exchanger provided as a heat sink in the electric motor for taking up heat from the circulating air thereby re-cooling the circulating air, the air/liquid heat exchanger being incorporated into the liquid cooling system of the stator.