Electric vehicle

1. An electric vehicle with an electric motor wherein the electric motor comprises

a plurality of electric motor modules, comprising

a first electric motor module, comprising a first rotor which has a first rotor shaft, wherein the first rotor shaft has a first shaft coupling structure, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft, wherein the second rotor shaft has a second shaft coupling structure, and

a rotational bearing by which the first rotor shaft is mounted,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures,

wherein the first and second shaft coupling structures are at least partially surrounded by the rotational bearing, and

wherein the first and second electric motor modules are capable of functioning independently of one another.

2. The electric vehicle according to claim 1 , wherein

at least two electric motor modules of the plurality of electric motor modules are structurally identical.

3. The electric vehicle according to claim 1 , wherein at least two electric motor modules of the plurality of electric motor modules are synchronous motors.

4. The electric vehicle according to claim 1 , wherein

the first shaft coupling structure comprises a projection that extends in an axial direction,

the second shaft coupling structure has a recess that extends in the axial direction; so that the first shaft coupling structure and the second shaft coupling structure abut one another in the axial direction along a contact surface, and

the contact surface forms an angle of at most 5° with an angle measurement plane which contains a rotational axis of the first or second rotor.

5. An electric vehicle with an electric motor wherein the electric motor comprises

a plurality of electric motor modules, comprising

a first electric motor module, comprising a first rotor which has a first rotor shaft, wherein the first rotor shaft has a first shaft coupling structure, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft, wherein the second rotor shaft has a second shaft coupling structure, and

a rotational bearing by which the first rotor shaft is mounted,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures, and

wherein

the rotational bearing comprises a first pivot bearing which comprises a first set of rolling elements arranged annularly, and

the rotational bearing comprises a second pivot bearing which comprises a second set of rolling elements that are arranged annularly and at an offset to the first set of rolling elements, and

the first and second shaft coupling structures are at least partially surrounded by the first pivot bearing and the second pivot bearing.

6. An electric vehicle with an electric motor wherein the electric motor comprises

a plurality of electric motor modules, comprising

a first electric motor module, comprising a first rotor which has a first rotor shaft, wherein the first rotor shaft has a first shaft coupling structure, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft, wherein the second rotor shaft has a second shaft coupling structure, and

a rotational bearing by which the first rotor shaft is mounted,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures, and

wherein

the electric motor further comprises a rotary encoder which comprises a rotary encoder coupling structure with a projection that extends in an axial direction, and

the rotary encoder is positively connected to either the first or second shaft coupling structure of an electric motor module.

7. The electric vehicle according to claim 6 , wherein

the electric motor has a brake which comprises a brake coupling structure with a projection that extends in an axial direction, and

the brake is positively connected to the first or second shaft coupling structure of an electric motor module or the rotary encoder.

8. The electric vehicle of claim 6 , wherein the first and second shaft coupling structures are at least partially surrounded by the rotational bearing.

9. An electric vehicle with an electric motor wherein the electric motor comprises

a first electric motor module comprising

a first rotor which has a first rotor shaft, and

a rotational bearing by which the first rotor shaft is mounted, and

wherein the first rotor shaft has a first shaft coupling structure, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft, wherein the second rotor shaft has a second shaft coupling structure,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures,

wherein the first and second shaft coupling structures are at least partially surrounded by the rotational bearing,

wherein the first rotor shaft and the second rotor shaft have a cooling duct, and

wherein the cooling duct extends through the first rotor and the second rotor.

10. An electric vehicle with an electric motor wherein the electric motor comprises

a plurality of electric motor modules, comprising

a first electric motor module, comprising a first rotor which has a first rotor shaft, wherein the first rotor shaft has a first shaft coupling structure, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft, wherein the second rotor shaft has a second shaft coupling structure, and

a rotational bearing by which the first rotor shaft is mounted,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures, and

a stator,

wherein at least one of the first rotor shaft and the second rotor shaft comprises

a central cooling duct that extends in an axial direction,

a feed branch duct that extends radially outwards and is connected to the central cooling duct, and

a discharge branch duct that extends outwards and is connected to the central cooling duct, and

wherein the stator comprises

a cooling fluid feed for supplying cooling fluid to the feed branch duct, and

a cooling fluid discharge for discharging cooling fluid from the discharge branch duct.

11. The electric vehicle according to claim 10 , wherein the cooling fluid feed has

a first shaft seal and a second shaft seal which form a shaft annular duct, and

a feed line that is configured to feed cooling fluid to the annular duct.

12. The electric vehicle according to claim 10 , wherein the first rotor comprises

a magnet carrier,

a plurality of permanent magnets fixed to the magnet carrier, and

a secondary duct which extends in the axial direction through the magnet carrier and is connected to the central cooling duct.

13. The electric vehicle according to claim 12 , wherein

the stator comprises stator electromagnets,

the permanent magnets of the first rotor are arranged radially outside of the stator electromagnets,

the rotor shaft has

a first sleeve section that extends in a first axial direction and

a second sleeve section that extends in a direction opposite to the first axial direction,

the first and second sleeve sections are symmetrical, and

the first and second sleeve sections contain cooling ducts.

14. The electric vehicle according to claim 13 , wherein

the first and second sleeve sections are configured on a tubular component,

the tubular component is fixed to a web, and

the web has a connection duct that extends radially outwards which connects the central cooling duct to an external duct in the tubular component.

15. The electric vehicle according to claim 10 , wherein the cooling fluid is coolant.

16. The electric vehicle of claim 10 , wherein the first and second shaft coupling structures are at least partially surrounded by the rotational bearing.

17. An electric vehicle with an electric motor wherein the electric motor comprises

a first electric motor module comprising a first rotor which has a first rotor shaft that comprises a first shaft coupling structure and a first cooling duct, and

at least a second electric motor module, comprising a second rotor which has a second rotor shaft that comprises a second shaft coupling structure and a second cooling duct,

wherein the first rotor shaft and the second rotor shaft are positively coupled with one another via the first and second shaft coupling structures, and

wherein the first and second cooling ducts are connected to one another.

18. The electric vehicle according to claim 17 , wherein

the first electric motor module has a first module housing comprising a first housing coupling structure,

the second electric motor module has a second module housing comprising a second housing coupling structure,

the first and second electric motor modules are positively connected to one another via the first and second housing coupling structures, and

the first and second housing coupling structures radially surrounds the first pivot bearing.

19. The electric vehicle according to claim 18 , wherein

the first housing coupling structure is at least partially formed by a first tapered housing ring,

the second housing coupling structure is at least partially formed by a second tapered housing ring, and

the first and second tapered housing rings are connected via a coupling clamp which has an at least partially tapered inner surface.