Interior magnet rotary machine

• US 5,191,256 A
• Filed: 12/15/1989
• Issued: 03/02/1993
• Est. Priority Date: 12/15/1989
• Status: Expired due to Fees

• Current Assignee: Lexington Capital Partners & Co., Inc.
• Original Assignee: American Motion Systems
• Inventors: Reiter, Frederick B. Jr., Koelblinger, Brad C., McGee, Daniel W., Murthy, Vamaraju S. R., Draper, John S.
• Primary Examiner(s): Skudy, R.
• Application Number:
  US07/452,301
• Time in Patent Office: 1,173 Days
• Field of Search: 310/261, 310/156, 310/262, 310/264, 310/265, 310/267, 310/269, 310/254, 310/216, 310/218
• US Class Current: 310/156.49
• CPC Class Codes: H02K 1/2726 the rotor consisting of a single magnet or two or more axially juxtaposed single magnets
• CPC Class Codes: H02K 1/2766 having a flux concentration effect
• CPC Class Codes: H02K 15/03 having permanent magnets

Abstract

A rotor for an interior magnet rotary machine, such as motors and generators, is mass produced by forming an elongated structure. This structure has channels in the periphery thereof which are parallel to the longitudinal axis of the structure. The elongated structure is cut into rotor frames of a predetermined length having channels extending from one end to the opposite end thereof. Magnets are placed in the channels. Pole pieces may be placed on the magnets in the channels.

The interior magnet rotary machine produced by this method has a rotor of a structure made of a rotor frame with channels extending from one end to the opposite end, and at least one magnet in a respective one of the channels. Thus, an efficient, low cost, mass producible, and easily assembled rotor for an interior magnet rotary machine is provided.

Claims

1. A rotor structure for a rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along an entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame; and

at least one magnet positioned in each of said channels, each of said magnets having a predetermined shape so as not to protrude radially outwardly beyond the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

2. The rotor structure according to claim 1 wherein said at least one magnet includes an inner surface and an outer surface opposite said inner surface, said inner magnet surface received against said each said channel, and further comprising at least one pole piece coextensively placed on said outer surface of said magnet.

3. The rotor structure according to claim 1 further comprising at least one endcap placed on at least one end of the rotor frame.

4. The rotor structure according to claim 1 wherein said at least one magnet has a predetermined shape conforming to a surface of said each of said channels.

5. The rotor structure according to claim 1 wherein said channels and said at least one magnet are V-shaped.

6. The rotor structure according to claim 1 wherein said channels and said at least one magnet are U-shaped.

7. The rotor structure according to claim 1 wherein each of said channels has a pair of opposing side surface portions and a medial surface portion located therebetween, and wherein said at least one magnet includes a pair of magnets positioned in each channel, with each one of said pair of magnets lying along a respective opposing side surface portion of the channel, said pair of magnets separated from the medial surface portion of said channel to form an air gap therebetween.

8. The rotor structure according to claim 1 wherein each of said channels has a pair of opposing side surface portions and a medial surface portion located therebetween, and wherein said at least one magnet includes three magnets in each channel, with a first magnet lying on the medial surface portion of said channel and the other two magnets lying on the respective side surface portions of each channel.

9. The rotor structure according to claim 1 wherein said at least one magnet includes an inner surface and an outer surface with opposite polarities, with said inner magnet surface positioned against said each of said channels.

10. The rotor structure according to claim 1 further comprising means for holding said at least one magnet in each of said channels.

11. The rotor structure according to claim 2 further comprising at least one endcap placed on at least one end of the rotor frame.

12. The rotor structure according to claim 2 wherein said at least one magnet has a predetermined shape conforming to a surface of said each of said channels.

13. The rotor structure according to claim 2 wherein said channels and said at least one magnet are U-shaped.

14. The rotor structure according to claim 2 wherein each of said channels has a pair of opposing side surface portions and a medial surface portion located therebetween, and wherein said at least one magnet includes a pair of magnets positioned in each channel, with each one of said pair of magnets lying along a respective opposing side surface portion of the channel, said pair of magnets separated from the medial surface portion of said channel to form an air gap therebetween.

15. The rotor structure according to claim 2 wherein said at least one magnet includes an inner surface and an outer surface with opposite polarities, with said inner magnet surface positioned against said each of said channels.

16. The rotor structure according to claim 2 wherein said at least one magnet has predetermined portions recessed from the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame to form an air gap of low magnetic permeability.

17. The rotor structure according to claim 16 further comprising a non-magnetically permeable cover in said air gap.

18. The rotor structure according to claim 2 wherein said at least one magnet has predetermined portions generally aligned with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

19. The rotor structure according to claim 2 wherein said at least one pole piece has an outer surface generally aligned with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

20. A rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along an entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame; and

at least one magnet positioned in each of said channels, each of said magnets having a predetermined shape so as not to protrude radially outwardly beyond the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame; and

a stator assembly surrounding said rotor frame with said at least one magnet in said channels, to thereby form a rotary machine.

21. The rotary machine according to claim 20 wherein said at least one magnet includes an inner surface and an outer surface opposite said inner surface, said inner magnet surface received against said each of said channels, and further comprising at least one pole piece coextensively placed on said outer surface of said magnet.

22. The rotary machine according to claim 20 further comprising at least one endcap placed on at least one end of the rotor frame.

23. The rotary machine according to claim 20 wherein said at least one magnet has a predetermined shape conforming to the surface of said channels.

24. The rotary machine according to claim 20 wherein said channels and said at least one magnet are V-shaped.

25. The rotor machine according to claim 20 wherein said channels and said at least one magnet are U-shaped.

26. The rotary machine according to claim 20 wherein each of said channels has a pair of opposing side surface portions and a medial surface portion located therebetween, and wherein said at least one magnet includes a pair of magnets positioned in each channel, with each one of said pair of magnets lying along a respective opposing side surface portion of the channel, said pair of magnets separated from the medial surface portion of said channel to form an air gap therebetween.

27. The rotary machine according to claim 20 wherein each of said channels has a pair of opposing side surface portions and a medial surface portion located therebetween, and wherein said at least one magnet includes three magnets in each channel, with a first magnet lying on the medial surface portion of said channel and the other two magnets lying on the respective side surface portions of each channel.

28. The rotor structure according to claim 20 wherein said at least one magnet includes an inner surface and an outer surface with opposite polarities, with said inner magnet surface positioned against the channel.

29. The rotary machine according to claim 21 wherein said at least one magnet has predetermined portions generally aligned with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

30. The rotor structure according to claim 21 wherein said at least one pole piece has an outer surface generally aligned with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

31. The rotary machine according to claim 20 further comprising means for holding said at least one magnet in each of said channels.

32. The rotary machine according to claim 20 further comprising an electrical driver circuit connected to said stator assembly.

33. A rotor structure for a rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of generally U-shaped channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along an entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame;

at least one generally U-shaped magnet positioned in each of said generally U-shaped channels so as not to protrude radially outwardly beyond the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame, each of said U-shaped magnets having an inner surface adjacent said channel magnetized at a first polarity and an outer surface opposite said inner surface magnetized at an opposite polarity; and

a pole piece mounted on the outer surface of each of said U-shaped magnets, each of said pole pieces having an inner surface adjacent the outer surface of said U-shaped magnet and conforming thereto to form a high permeability magnetic circuit, each of said pole pieces having an outer surface opposite said inner surface being flush with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

34. The rotor structure of claim 33 wherein each of said generally U-shaped magnets includes free end portions opposite a bight portion, and wherein the free end portions of said U-shaped magnets are recessed from the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame to form air gaps of low magnetic permeability adjacent the free end portions of said U-shaped magnets.

35. The rotor structure of claim 34 further comprising a non-permeable cover positioned within each recess adjacent said free end portions of said U-shaped magnets.

36. A rotor structure for a rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along an entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame, each of said channels having a pair of opposing side surface portions and a medial surface portion located therebetween;

a pair of bar magnets positioned in each channel, each one of said bar pair of magnets lying along a respective opposing side surface portion of said channel, each of said bar magnets having a first surface adjacent a respective side surface portion of said channel magnetized at a first polarity and a second surface opposite said first surface magnetized at an opposite polarity; and

a generally triangular pole piece mounted between the second surfaces of the bar magnets in each pair thereof to form a high permeability magnetic circuit, an outer surface of each pole piece being flush with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

37. The rotor structure of claim 36 wherein each of said bar magnets includes a third surface between said first and second surfaces being recessed from the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame to form air gaps of low magnetic permeability.

38. The rotor structure of claim 37 further comprising a non-permeable cover positioned within a recess adjacent said third surfaces of said bar magnets.

39. A rotor structure for a rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of generally V-shaped channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along an entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame; and

at least one generally V-shaped magnet positioned in each of said generally V-shaped channels, each of said V-shaped magnets having an inner surface adjacent said channel magnetized at a first polarity and an outer surface opposite said inner surface magnetized at an opposite polarity; and

a pole piece mounted on the outer surface of each of said U-shaped magnets, each of said pole pieces having an inner surface adjacent the outer surface of said V-shaped magnet and conforming thereto to form a high permeability magnetic circuit, each of said pole pieces having an outer surface opposite said inner surface being flush with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

40. The rotor structure of claim 39 wherein each of said generally V-shaped magnets includes free end portions opposite a bight portion, and wherein the free end portions of said V-shaped magnets are recessed from the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame to form air gaps of low magnetic permeability adjacent the free end portions of said V-shaped magnets.

41. The rotor structure of claim 40 further comprising a non-permeable cover positioned within each recess adjacent said free end portions of said V-shaped magnets.

42. A rotor structure for a rotary machine comprising:

a rotor frame comprising a monolithic unitary body of magnetically permeable material and having an elongate generally cylindrical shape with outer radial surface portions defining an imaginary circular cylindrical surface of said rotor frame, said rotor frame including a series of channels formed in the outer radial surface portions of said rotor frame and opening radially outwardly therefrom, each of said channels extending continuously along the entire length of said rotor frame and opening outwardly from each opposing end of said rotor frame, each of said channels having a pair of opposing side surface portions and a medial surface portion located therebetween; and

three magnets mounted in each channel, a first magnet lying on the medial surface portion of said channel and the second and third magnets lying on respective side surface portions of each channel, each of said magnets having an inner surface adjacent said channel magnetized at a first polarity and an outer surface opposite said inner surface magnetized at an opposite polarity; and

a pole piece mounted on an outer surface of each of said magnets, each of said pole pieces having an inner surface adjacent the outer surface of said magnets and conforming thereto to form a high permeability magnetic circuit, each of said pole pieces having an outer surface opposite said inner surface being flush with the imaginary circular cylindrical surface defined by the outer radial surface portions of said rotor frame.

43. The rotor structure of claim 42 wherein a predetermined portion of each of said second and third magnets is recessed from the imaginary cylindrical surface defined by the outer radial surface portions of said rotor frame to form air gaps of low magnetic permeability adjacent to the predetermined portions of said second and third magnets.

44. The rotor structure of claim 43 further comprising a non-permeable cover positioned within each recess adjacent said predetermined portions of said second and third magnets respectively.