Electric machine and rotor with cooling channel

1. A rotor for an electric machine, the rotor comprising:

a laminated rotor core with a central longitudinal axis;

a filler body comprising an aluminum die-cast alloy cast onto the laminated rotor core;

the filler body including an inner shell surface with a first multiplicity of fins extending radially from the inner shell surface toward the central longitudinal axis, the first multiplicity of fins defining a multiplicity of air flow channels between each pair of adjacent fins, each of the multiplicity of air flow channels running parallel to the central longitudinal axis;

a first shaft journal having an air inlet opening;

a second shaft journal having an air outlet opening; and

a ventilation unit;

wherein the filler body connects the laminated rotor core rotationally conjointly to the first shaft journal and the second shaft journal;

the laminated rotor core includes a central axial bore partially filled by the filler body forming an axial cooling channel for cooling air within the central axial bore;

the shaft journals drive the ventilation unit; and

rotation of the ventilation unit draws an air stream in via the air inlet opening, conveys said air stream through the axial cooling channel, and discharges said air stream via the air outlet opening.

2. The rotor as claimed in claim 1 , wherein:

the electric machine comprises a synchronous motor;

the laminated rotor core includes receiving channels within which permanent magnets are received; and

free spaces between the permanent magnets and the receiving channels are filled by the filler body to fix the permanent magnets within the receiving channels.

3. The rotor as claimed in claim 1 , wherein the electric machine comprises an asynchronous motor; and

the rotor furthermore comprises:

a first short-circuiting ring comprising an aluminum die-cast alloy cast onto the laminated rotor core;

a second short-circuiting ring comprising an aluminum die-cast alloy cast onto the laminated rotor core; and

multiple short-circuiting bars comprising an aluminum die-cast alloy cast into axial grooves of an outer shell surface of the laminated rotor core such that the short-circuiting bars are connected in each case to both the first short-circuiting ring and the second short-circuiting ring.

4. The rotor as claimed in claim 1 , wherein:

the ventilation unit comprises a conveying spiral arranged within the axial cooling channel; and

a drive shaft of the conveying spiral is mounted rotationally conjointly within the first shaft journal and the second shaft journal.

5. The rotor as claimed in claim 1 , wherein the ventilation unit comprises fan impeller blades integrated into the shaft journals.

6. The rotor as claimed in claim 1 , wherein the ventilation unit comprises an axial fan impeller insert connected rotationally conjointly in positively locking fashion to the filler body and arranged within the axial cooling channel.

7. The rotor as claimed in claim 1 , further comprising multiple

second projections of the filler body projecting radially inward from the inner shell surface of the filler body;

wherein the shaft journals are fastened to the filler body with multiple connectors inserted in the multiple second projections.

8. The rotor as claimed in claim 1 , wherein an inner shell surface of the filler body comprises a first centering shoulder for the first shaft journal and a second centering shoulder for the second shaft journal.

9. The rotor as claimed in claim 1 , wherein the laminated rotor core is connected to the filler body in positively locking and non-positively locking fashion in the axial direction.

10. An electric machine for a vehicle, the electric machine comprising:

a rotor with a rotor shaft mounted in two rolling bearings, the rotor comprising:

a laminated rotor core with a central longitudinal axis;

the filler body including an inner shell surface with a first multiplicity of fins extending radially from the inner shell surface toward the central longitudinal axis, the first multiplicity of fins defining a multiplicity of air flow channels between each pair of adjacent fins, each of the multiplicity of air flow channels running parallel to the central longitudinal axis;

a filler body comprising an aluminum die-cast alloy cast onto the laminated rotor core;

a first shaft journal having an air inlet opening;

a second shaft journal having an air outlet opening; and

a ventilation unit;

wherein the filler body connects the laminated rotor core rotationally conjointly to the first shaft journal and the second shaft journal;

the laminated rotor core includes a central axial bore partially filled by the filler body forming an axial cooling channel for cooling air within the central axial bore;

the shaft journals drive the ventilation unit; and

rotation of the ventilation unit draws an air stream in via the air inlet opening, conveys said air stream through the axial cooling channel, and discharges said air stream via the air outlet opening;

a stator having a laminated stator core and stator winding heads arranged at opposite end sides of the laminated stator core; and

a housing surrounding the stator in a radial direction;

wherein the stator and the housing form, between them, an outer cooling channel running along the laminated stator core and the stator winding heads and connecting two opposite end sides of the stator winding heads to one another;

the ventilation unit forms a suction side on a first end side of the laminated rotor core and a pressure side on a second end side of the laminated rotor core, as the rotor shaft rotates, such that air is drawn in on the suction side and conveyed through the axial cooling channel of the rotor and the outer cooling channel; and

the housing comprises a liquid cooling channel of a circulation cooling circuit, within which a cooling liquid circulates and cools the housing.