CAST-IN-PLACE INDUCTION ROTOR END RINGS WITH IMPROVED INTERLOCKS

• US 20140132105A1
• Filed: 11/13/2012
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: KLEBER, Richard M.
• Granted Patent: US 8,994,242 B2
• Time in Patent Office: Days
• US Class Current: 310/211
• CPC Class Codes: H02K 15/0012 Manufacturing cage rotors
• CPC Class Codes: H02K 17/16 having rotors with internally short-circuited windings, e.g. cage rotors
• CPC Class Codes: H02K 17/20 having deep-bar rotors

Abstract

An induction motor has a rotor core including a plurality of conductor bars and a shorting end ring having a plurality of grooves aligned with and mated to the first ends of the conductor bars. The rotor core further includes a cylindrically shaped steel laminate stack including a plurality of longitudinal grooves distributed around the periphery of the steel laminate stack. The conductor bars are each located in one of the plurality of longitudinal grooves and each includes a first end projecting from a first end of the steel laminate stack. The rotor core further includes an end sheet located to the end of the steel laminate stack, the end sheet including a retention feature configured to retain the shorting end ring to the end sheet.

Claims

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.