Rotary electric machine

1. A rotating electrical machine comprising:

a rotor having a laminated rotor core arranged on a rotor shaft;

at least one end winding cover that terminates the laminated rotor core in an axial direction of the rotor shaft;

wherein the end winding cover comprises at least one inner face that faces the laminated rotor core in the axial direction of the rotor shaft; and

a balancing ring arranged concentrically along an inside of a perimeter of the at least one inner face of the end winding cover and remote from both the rotor shaft and the rotor core;

wherein the balancing ring is attached to the at least one inner face of the end winding cover by a rolling undulation formed in a side wall of the end winding cover and which firmly clamps the balancing ring against the inner face.

2. The rotating electrical machine of claim 1 , further comprising an end winding cover at each of a first end and a second end of the rotor, and a balancing ring arranged concentrically around the rotor shaft on the inner face of each of the end winding covers.

3. The rotating electrical machine of claim 1 , comprising a plurality of rolling undulations in the side wall of the end winding cover.

4. The rotating electrical machine of claim 1 , wherein the balancing ring has an undercut in the axial direction of the rotor shaft configured for engagement with the end winding cover.

5. The rotating electrical machine of claim 1 , wherein the balancing ring comprises an alloy that contains iron, chromium, and nickel, wherein chromium is contained in the alloy in a percentage by weight of between 18 and 19, and nickel is contained in the alloy in a percentage by weight of between 12 and 13.

6. The rotating electrical machine of claim 5 , wherein the balancing ring comprises an alloy composition Fe remainder Cr a Ni b Mn c C d Si e P f S g N h , where each of the subscripts a, b, c, d, e, f, g and h indicates a percentage by weight, wherein 18≤a≤19; 12≤b≤13; 0≤c≤1.4; 0≤d≤0.055; 0≤e≤0.6; 0≤f≤0.04; 0≤g≤0.008 and 0≤h≤0.1.

7. The rotating electrical machine of claim 1 , wherein the end winding cover comprises an alloy that contains iron, chromium and nickel, wherein chromium is contained in the alloy in a percentage by weight of between 18 and 19, and nickel is contained in the alloy in a percentage by weight of between 12 and 13.

8. The rotating electrical machine of claim 7 , wherein the end winding cover comprises an alloy composition Fe remainder Cr a Ni b Mn c C d Si e P f S g N h , where each of the subscripts a, b, c, d, e, f, g and h indicates a percentage by weight, wherein 18≤a≤19; 12≤b≤13; 0≤c≤1.4; 0≤d≤0.055; 0≤e≤0.6; 0≤f≤0.04; 0≤g≤0.008 and 0≤h≤0.1.

9. The rotating electrical machine of claim 1 , wherein the end winding cover is produced in a deep-drawing process.

10. A motor vehicle, comprising:

a drive train including an electric motor comprising:

a rotor having a laminated rotor core arranged on a rotor shaft;

at least one end winding cover that terminates the laminated rotor core in an axial direction of the rotor shaft;

wherein the end winding cover comprises at least one inner face that faces the laminated rotor core in the axial direction of the rotor shaft; and

a balancing ring arranged concentrically along an inside of a perimeter of the at least one inner face of the end winding cover and remote from both the rotor shaft and the rotor core;

wherein the balancing ring is attached to the at least one inner face of the end winding cover by a rolling undulation formed in a side wall of the end winding cover and which firmly clamps the balancing ring against the inner face.

11. The motor vehicle of claim 10 , comprising an end winding cover at each of a first end and a second end of the rotor, and a balancing ring arranged concentrically around the rotor shaft on the at least one inner face of each of the end winding covers.

12. The rotating electrical machine of claim 10 , comprising a plurality of rolling undulations in the side wall of the end winding cover.

13. The motor vehicle of claim 10 , wherein the balancing ring has an undercut in the axial direction of the rotor shaft configured for engagement with the end winding cover.

14. The motor vehicle of claim 10 , wherein the balancing ring comprises an alloy that contains iron, chromium, and nickel, wherein chromium is contained in the alloy in a percentage by weight of between 18 and 19, and nickel is contained in the alloy in a percentage by weight of between 12 and 13.

15. The motor vehicle of claim 14 , wherein the balancing ring comprises an alloy composition Fe remainder Cr a Ni b Mn c C d Si e P f S g N h , where each of the subscripts a, b, c, d, e, f, g and h indicates a percentage by weight, wherein 18≤a≤19; 12≤b≤13; 0≤c≤1.4; 0≤d≤0.055; 0≤e≤0.6; 0≤f≤0.04; 0≤g≤0.008 and 0≤h≤0.1.

16. The motor vehicle of claim 10 , wherein the end winding cover comprises an alloy that contains iron, chromium and nickel, wherein chromium is contained in the alloy in a percentage by weight of between 18 and 19, and nickel is contained in the alloy in a percentage by weight of between 12 and 13.

17. The motor vehicle of claim 16 , wherein the end winding cover comprises an alloy composition Fe remainder Cr a Ni b Mn c C d Si e P f S g N h , where each of the subscripts a, b, c, d, e, f, g and h indicates a percentage by weight, wherein 18≤a≤19; 12≤b≤13; 0≤c≤1.4; 0≤d≤0.055; 0≤e≤0.6; 0≤f≤0.04; 0≤g≤0.008 and 0≤h≤0.1.

18. The motor vehicle of claim 10 , wherein the motor vehicle comprises an electric or hybrid vehicle.