Squirrel-cage rotor for an asynchronous machine

1. A squirrel-cage rotor for an asynchronous machine, the squirrel-cage rotor comprising:

a first shaft journal comprising a first shaft journal bearing surface;

a second shaft journal comprising a second shaft journal bearing surface;

a laminated rotor core; and

a filler body cast onto the laminated rotor core connecting the filler body and the laminated rotor core in a rotationally fixed manner;

wherein the filler body is connected to the shaft journal bearing surfaces in a rotationally fixed manner and a torque applied to the shaft journals is transmitted to the laminated rotor core;

wherein the filler body comprises three spokes extending in a radial direction;

each of the three spokes includes two respective threaded bores at opposing ends; and

the first shaft journal bearing surface is attached to the laminated rotor core by three screws fastened into the threaded bores of the three spokes at a first end of the laminated rotor core and the second shaft journal bearing surface is attached to the laminated rotor core by three screws fastened into the threaded bores of the three spokes at a second end of the laminated rotor core.

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

the first shaft journal bearing surface includes a first axial bore;

the second shaft journal bearing surface includes a second axial bore;

the filler body includes a third axial bore;

the third axial bore connects the first axial bore to the second axial bore; and

the first bore, the second bore, and the third bore form a cooling duct running through the first shaft journal, the filler body, and the second shaft journal.

3. The squirrel-cage rotor as claimed in claim 2 , further comprising:

a first short-circuiting ring; and

a second short-circuiting ring;

wherein the first shaft journal includes a first radial bore; and

the second shaft journal includes a second radial bore;

the first radial bore is connected to the first axial bore;

the second radial bore is connected to the second axial bore;

the first short-circuiting ring radially surrounds the first radial bore;

the second short-circuiting ring radially surrounds the second radial bore; and

rotation of the shaft journals drive a cooling medium out of the radial bores radially to the outside in the direction of the short-circuiting rings and can cool the short-circuiting rings.

4. The squirrel-cage rotor as claimed in claim 1 , wherein the laminated rotor core is connected to the filler body in an interlocking and force-fitting manner in the axial direction.

5. The squirrel-cage rotor as claimed in claim 1 , wherein the shaft journal bearing surfaces each includes an attachment arranged on the end side for centering purposes.

6. The squirrel-cage rotor as claimed in claim 1 , wherein the shaft journal bearing surfaces each include an end plate including three through holes for fastening the screws to the filler body.

7. An asynchronous machine comprising:

a stator;

a first stator end winding;

a second stator end winding; and

a squirrel-cage rotor comprising:

a first shaft journal comprising a first shaft journal bearing surface;

a second shaft journal comprising a second shaft journal bearing surface;

a laminated rotor core; and

a filler body cast onto the laminated rotor core connecting the filler body and the laminated rotor core in a rotationally fixed manner;

wherein the filler body is connected to the shaft journals in a rotationally fixed manner and a torque applied to the shaft journals is transmitted to the laminated rotor core;

wherein the first stator end winding surrounds a first short-circuiting ring; and

the second stator end winding surrounds a second short-circuiting ring; and

rotation of the shaft journals drive a cooling medium out of radial bores radially to the outside in the direction of the stator end windings and can cool the stator end windings;

wherein the filler body comprises three spokes extending in a radial direction;

each of the three spokes includes two respective threaded bores at opposing ends; and

the first shaft journal bearing surface is attached to the laminated rotor core by three screws fastened into the threaded bores of the three spokes at a first end of the laminated rotor core and the second shaft journal bearing surface is attached to the laminated rotor core by three screws fastened into the threaded bores of the three spokes at a second end of the laminated rotor core.