Cast-in-place induction rotor end rings with improved interlocks

1. An induction motor, comprising:

a rotor core comprising:

a cylindrically shaped steel laminate stack including a plurality of longitudinal grooves distributed around the periphery of the steel laminate stack; and

a plurality of conductor bars, each located in one of the plurality of longitudinal grooves and each comprising a first end projecting from a first end of the steel laminate stack;

a shorting end ring comprising a plurality of grooves aligned with and mated to the first ends of the conductor bars; and

the rotor core further comprising an end sheet located to the end of the steel laminate stack, the end sheet comprising a retention feature configured to retain the shorting end ring to the end sheet.

2. The induction motor of claim 1 , wherein the retention feature includes a tab extending from the end sheet.

3. The induction motor of claim 2 , wherein the tab comprises a thin neck section at a base of the tab and a thicker section away from the base of the tab.

4. The induction motor of claim 1 , wherein the retention feature comprises a plurality of tabs spaced symmetrically about a surface of the end sheet.

5. The induction motor of claim 4 , wherein at least one of the conductor bars includes a hole in the first end of the conduction bar;

wherein the shorting end ring is molded upon the rotor core; and

wherein the hole in the first end of the conduction bar retains the end ring to the rotor core.

6. The induction motor of claim 4 , wherein each of the plurality of the conductor bars includes a respective hole in the respective first end;

wherein the shorting end ring is molded upon the rotor core; and

wherein the holes in the first ends of the plurality of conduction bars retain the end ring to the rotor core.

7. The induction motor of claim 4 , further comprising a lock ring retaining the end ring to the rotor core.

8. The induction motor of claim 4 , wherein the end sheet further comprises a retention end ring.

9. The induction motor of claim 8 , wherein the retention end ring includes details to retain the shorting end ring to the end sheet.

10. The induction motor of claim 9 , wherein the details comprise one of annular grooves, bumps, or tabs.

11. The induction motor of claim 8 , wherein the end sheet and the retention end ring are constructed of copper; and

wherein the shorting end ring is a molded aluminum shorting end ring.

12. The induction motor of claim 1 , wherein the retention feature comprises a retention end ring.

13. The induction motor of claim 1 , wherein the retention end ring is affixed to the end sheet.

14. The induction motor of claim 1 , wherein the rotor core includes a retention feature on both sides of the rotor core.

15. The induction motor of claim 1 , wherein the end sheet comprises a copper end sheet.

16. The induction motor of claim 15 , wherein the steel laminate stack comprises a plurality of steel sheets of a first thickness; and

wherein the copper end sheet is a second thickness greater than the first thickness.

17. An induction motor, comprising:

a rotor core comprising:

a cylindrically shaped steel laminate stack including a plurality of longitudinal grooves distributed around the periphery of the steel laminate stack; and

a plurality of conductor bars, each located in one of the plurality of longitudinal grooves and each comprising a first end projecting from a first end of the steel laminate stack and each conductor bar comprising a hole in the projecting first end;

a shorting end ring comprising a plurality of grooves aligned with and mated to the first ends of the conductor bars; and

the rotor core further comprising an end sheet located to the end of the steel laminate stack, the end sheet comprising a plurality of tabs stamped from a surface of the end sheet and projecting toward the shorting end ring configured to retain the shorting end ring to the end sheet;

wherein the holes in the first ends of the conductor bars are configured to retain the shorting end ring to the rotor core.