Motors with pre-manufactured conductors or end rings and manufacturing methods thereof

1. A device comprising:

a stator or a rotor configured to be magnetically coupled through an air gap;

a plurality of slots distributed along a perimeter of the stator or rotor;

a plurality of metal bars, each placed into one of the plurality of slots; and

an end ring having a plurality of openings, wherein each opening is configured to receive an end of one of the metal bars, and wherein a lock feature is configured to improve a mechanical attachment between the end ring and the said metal bar, and wherein the lock feature is configured to maintain a separation between the metal bar and an inner surface of a corresponding opening in the end ring, thereby preventing undesirable interaction between the metal bar and the end ring.

2. The device of claim 1 , wherein:

the said metal bar is made of a different material from the end ring.

3. The device of claim 2 , wherein:

the said metal bar is made of copper, and the end ring is made of aluminum.

4. The device of claim 2 , wherein:

one between the said metal bar and the end ring is made of copper, and the other is made of aluminum, and an interface material is configured to exist between the said metal bar and the wall of the opening accommodating the said metal bar to prevent metallic action between the said metal bar and the end ring.

5. The device of claim 1 , wherein:

one of the metal bars and the slot accommodating it are configured to have an attachment feature to improve the attachment of the metal bar to the slot.

6. The device of claim 1 , wherein:

the end ring is made of copper, and the metal bars are manufactured through a process step of casting aluminum into the plurality of slots, and wherein during the process step of casting aluminum the metal bars are attached mechanically to the end ring by the aluminum material.

7. A method comprising:

configuring a stator or rotor to be magnetically coupled through an air gap;

placing a plurality of slots distributed along a perimeter of the stator or rotor;

inserting a plurality of metal bars into the plurality of slots; and

configuring an end ring having plurality of openings, wherein each opening is configured to receive an end of one of the metal bars, and wherein a lock feature is configured to improve a mechanical attachment between the end ring and the said metal bar, and wherein the lock feature is configured to maintain a separation between the metal bar and an inner surface of a corresponding opening in the end ring, thereby preventing undesirable interaction between the metal bar and the end ring.

8. The method of claim 7 , wherein:

the said metal bar is made of a different material from the end ring.

9. The method of claim 8 , wherein:

the said metal bar is made of copper, and the end ring is made of aluminum.

10. The method of claim 8 , further comprising:

placing an interface material between the said metal bar and the end ring.

11. The method of claim 8 , wherein:

the end ring is manufactured by casting a metal material around the plurality of metal bars.

12. An apparatus comprising:

a stator magnetically coupled to a rotor through an air gap;

a plurality of slots distributed along a perimeter of the apparatus and configured to accommodate a plurality of conductors, wherein each of the slots is configured to accommodate one of the conductors; and

an end ring having a plurality of openings, wherein each opening is configured to receive an end of one of the conductors, and wherein a lock feature is configured to improve a mechanical attachment between the end ring and the said conductor, and wherein the lock feature is configured to maintain a separation between the metal bar and an inner surface of a corresponding opening in the end ring, such that the metal bar is positioned approximately in the middle of the corresponding opening, thereby preventing undesirable interaction between the metal bar and the end ring.

13. The apparatus of claim 12 , wherein:

the said conductor is made of a different material from the end ring.

14. The apparatus of claim 13 , wherein:

the said metal bar is made of copper, and the end ring is made of aluminum.

15. The apparatus of claim 13 , wherein:

one between the said conductor and the end ring is made of copper, and the other is made of aluminum, and an interface material is configured to exist between the said conductor and the wall of the opening accommodating the said conductor to prevent metallic action between the said conductor and the end ring.

16. The apparatus of claim 13 , wherein:

the end ring is made of copper, and the plurality of conductors is manufactured through a process step of casting aluminum into the plurality of slots, and wherein during the process step of casting aluminum the plurality of conductors are attached mechanically to the end ring by the aluminum material.

17. The apparatus of claim 13 , wherein:

the plurality of conductors is copper bars, and the end ring is manufactured through a process step of casting aluminum around the copper bars, and during the process step of casting aluminum, molten aluminum enters a space between the plurality of slots and the copper bars to strengthen an attachment between the plurality of slots and the copper bars.

18. The apparatus of claim 12 , wherein:

one of the plurality of conductors and the slot accommodating it are configured to have an attachment feature to improve the attachment of the conductor to the slot.

19. The apparatus of claim 18 , wherein:

the attachment feature includes a cut out on a wall of the slot.

20. The apparatus of claim 18 , wherein:

the attachment feature includes a protrusion on the conductor.