INDUCTION ROTOR ASSEMBLY AND METHOD OF MANUFACTURING SAME

• US 20120293036A1
• Filed: 05/20/2011
• Published: 11/22/2012
• Est. Priority Date: 05/20/2011
• 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., Agapiou, John S.
• Granted Patent: US 9,083,221 B2
• Time in Patent Office: Days
• US Class Current: 310/211
• CPC Class Codes: H02K 15/0012 Manufacturing cage rotors
• CPC Class Codes: H02K 17/20 having deep-bar rotors
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A method of manufacturing a rotor assembly includes placing a generally cylindrical rotor core in a die. The rotor core has axial grooves spaced about a perimeter of the rotor core. The grooves may be formed by stacked laminated disks. Material is cast around the annular rotor core in the die such that the cast material forms conductor bars that fill the grooves and first end ring portions at opposing ends of the rotor core connected with the conductor bars. Each of the first end ring portions has substantially a first axial width. The rotor core with cast conductor bars and cast first end ring portions is then removed from the die. A respective second end ring portion is welded to each of the cast first end ring portions to form end ring assemblies. Each second end ring portion has a second axial width greater than the first axial width.

Claims

1. A method of manufacturing a rotor assembly comprising:

placing a generally cylindrical rotor core in a die;

wherein the rotor core has axial grooves spaced about a perimeter of the rotor core;

casting material around the annular rotor core in the die such that the cast material forms conductor bars that fill the grooves and first end ring portions at opposing ends of the rotor core connected with the conductor bars;

wherein each of the first end ring portions has substantially a first axial width;

removing the rotor core with cast conductor bars and cast first end ring portions from the die; and

welding a respective second end ring portion to each of the cast first end ring portions to form end ring assemblies;

wherein each of the second end ring portions has a second axial width greater than the first axial width.

2. The method of claim 1, wherein the welding is spin welding.

3. The method of claim 1, wherein the welding is one of friction stir welding, gas metal arc welding, gas tungsten art welding, plasma arc welding, laser beam welding, and electron beam welding.

4. The method of claim 1, further comprising:

machining a weld bead at an outer surface of the welded end ring portions after the welding.

5. The method of claim 1, further comprising:

machining a weld bead at an inner surface of the welded end ring portions after the welding.

6. The method of claim 1, wherein the material forming the conductor bars and the first end ring portions is a copper alloy.

7. The method of claim 1, wherein each of the conductor bars has substantially a first thickness;

and wherein the first axial width is substantially the same as the first thickness.

8. A method of manufacturing a rotor assembly comprising:

stacking laminated disks to form a rotor core;

placing the rotor core in a die;

wherein the rotor core defines an axis and has grooves spaced about a perimeter of the rotor core;

placing a copper alloy in the die to cast conductor bars and first end ring portions around the annular rotor core such that the conductor bars fill the grooves, the first end ring portions are at opposing ends of the rotor core, and the conductor bars connect the first end ring portions;

wherein each of the end ring portions is substantially a first axial width;

removing the rotor core with cast conductor bars and cast first end ring portions from the die;

welding second end ring portions to the cast first end ring portions to form end ring assemblies each having substantially an axial width at least three times greater than the first axial width; and

machining weld flash at the second end ring portions.

9. The method of claim 8, wherein each of the conductor bars is substantially a first thickness;

and wherein the first axial width is substantially the same as the first thickness.

10. The method of claim 8, wherein the welding is spin welding.

11. The method of claim 8, wherein the welding is one of friction stir welding, brazing, gas metal arc welding, gas tungsten art welding, plasma arc welding, laser beam welding, and electron beam welding.

12. A rotor assembly comprising:

an annular rotor core that defines an axis and has an outer surface with a perimeter and grooves spaced about a perimeter of the rotor core;

a copper alloy cast in the grooves to define conductor bars connected with one another and first end ring portions unitary with the conductor bars at opposing ends of the conductor bars; and

second end ring portions welded to the cast first end ring portions.

13. The rotor assembly of claim 12, wherein each of the conductor bars is substantially a first thickness, wherein each of the first end ring portions unitary with the conductor bars is substantially a first axial width substantially the same as the first thickness;

and

wherein each of the second end ring portions is substantially a second axial width at least twice the first axial width.