Rotor of a synchronous induction electric motor, and a method of producing a rotor

• US 20030173861A1
• Filed: 11/13/2002
• Published: 09/18/2003
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kawaguchi, Hitoshi, Yoshino, Hayato, Takita, Yoshio
• Granted Patent: US 7,102,259 B2
• Time in Patent Office: Days
• US Class Current: 310/261
• CPC Class Codes: H02K 1/22 Rotating parts of the magnetic circuit
• CPC Class Codes: H02K 1/246 Variable reluctance rotors
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 15/0012 Manufacturing cage rotors
• CPC Class Codes: H02K 17/165 characterised by the squirrel-cage or other short-circuited windings
• CPC Class Codes: H02K 17/20 having deep-bar rotors

Abstract

A rotor of a synchronous induction electric motor according to the present invention includes a slot for generating induction torque and a slit for generating reluctance torque. The slot and the slit are filled up with aluminum which is short-circuited by an end-ring at each of both ends of the rotor, and the slit includes a non-filling part penetrating in the direction of the rotational axis and not filled up with the aluminum.

Claims

1. A rotor of a synchronous induction electric motor comprising:

a slot for generating induction torque, and

a slit for generating reluctance torque,

wherein the slot and the slit are filled up with aluminum which is short-circuited by an end-ring at each of both ends of the rotor, and the slit includes a non-filling part penetrating in a direction of a rotational axis and not filled up with the aluminum.

2. The rotor of the synchronous induction electric motor of the claim 1, wherein the non-filling part is provided at the slit which is close to a center of the rotor.

3. The rotor of the synchronous induction electric motor of the claim 2, wherein the non-filling part is provided at the slit which is the closest to the center of the rotor.

4. The rotor of the synchronous induction electric motor of the claim 1, wherein the non-filling part is provided close to a center of the slit.

17. A synchronous induction electric motor comprising the rotor of the synchronous induction electric motor of the claim 1.

21. A sealed type compressor comprising the synchronous induction electric motor of claim 17.

22. A refrigerator comprising the sealed type compressor of claim 21.

23. An air conditioner comprising the sealed type compressor of claim 21.

25. The rotor of the synchronous induction electric motor of claim 1, wherein the slit is located to be in parallel to d-axis.

5. A rotor of a synchronous induction electric motor comprising:

a slot for generating induction torque, and

a slit for generating reluctance torque,

wherein the slot and the slit are filled up with aluminum which is short-circuited by an end-ring at each of both ends of the rotor, and the rotor includes a gas vent hole penetrating in a direction of a rotational axis and shaped to make magnetic resistance in a direction of d-axis small as much as possible.

6. The rotor of the synchronous induction electric motor of the claim 5, wherein the gas vent hole has a short axis, and a long axis which is in the direction of d-axis and in a radial direction.

7. The rotor of the synchronous induction electric motor of the claim 6, wherein the gas vent hole is an oval.

8. A rotor of an electric motor comprising:

a layered steel plate made by layering one or a plurality of electro-magnetic steel plates, in which a gas vent hole penetrating in a direction of a rotational axis and being concavo-convex inside is formed.

9. The rotor of the electric motor of claim 8, wherein the rotor includes a first block made by layering one or a plurality of first rotor-punching plates in which the gas vent hole whose one end is closed is provided, a second block made by layering one or a plurality of second rotor-punching plates in which the gas vent hole wholly open is provided, and a third block made by layering one or a plurality of third rotor-punching plates in which the gas vent hole whose end opposite to a closed one end of the first rotor-punching plates is closed is provided, and wherein the gas vent hole penetrating in the direction of the rotational axis and being concavo-convex inside is formed by combining the first block, the second block and the third block.

10. The rotor of the electric motor of claim 9, wherein the gas vent hole penetrating in the direction of the rotational axis and being concavo-convex inside is formed by repeatedly layering the first block, the second block, and the third block in order.

11. The rotor of the electric motor of claim 9, wherein the gas vent hole is circular.

12. The rotor of the electric motor of claim 11, wherein the gas vent hole in the first rotor-punching plate and the gas vent hole in the third rotor-punching plate are semicirculars.

14. The rotor of the electric motor of claim 8, wherein the gas vent hole is wholly open at an entrance side of a gas flow, and a part inside the gas vent hole, at an outer circumferential side of the rotor, is closed at an exit side of the gas flow.

16. The rotor of the electric motor of claim 8, wherein the gas vent hole is shaped to make magnetic resistance in a direction of d-axis small as much as possible.

18. A synchronous induction electric motor comprising the rotor of the electric motor of the claim 8.

19. An induction electric motor comprising the rotor of the electric motor of the claim 8.

20. A brushless DC motor comprising the rotor of the electric motor of the claim 8.

13. A rotor of an electric motor including a layered steel plate made by layering one or a plurality of electro-magnetic steel plates, comprising:

a gas vent hole penetrating in a direction of a rotational axis and formed in the layered steel plate,

wherein the gas vent hole is wholly open at an entrance side of a gas flow, and a part inside the gas vent hole, at an outer circumferential side of the rotor, is closed at an exit side of the gas flow.

15. The rotor of the electric motor of claim 13, wherein the rotor includes a first block made by layering one or a plurality of first rotor-punching plates in which the gas vent hole whose one end is closed is provided, a second block made by layering one or a plurality of second rotor-punching plates in which the gas vent hole wholly open is provided, and a third block made by layering one or a plurality of third rotor-punching plates in which the gas vent hole whose end opposite to a closed one end of the first rotor-punching plates is closed is provided, and wherein the entrance side of the gas flow is composed of the second block, and the exit side of the gas flow is composed of one of the first block and the third block, and the gas vent hole at the exit side of the gas flow includes a closed part.

24. A producing method of a rotor of a synchronous induction electric motor, wherein a slot for generating induction torque and a slit for generating reluctance torque are included, the slot and the slit are filled up with aluminum which is short-circuited by an end-ring at each of both ends of the rotor, and the slit includes a non-filling part penetrating in a direction of a rotational axis and not filled up with the aluminum, the producing method comprising:

when the slot and the slit of the rotor are filled up with the aluminum by die-casting,

putting a plate-type mold onto the non-filling part beforehand,

performing the die-casting, and

taking the plate-type mold out when taking the rotor out of a mold of the die-casting.