Rotary electric motor having magnetically isolated stator and rotor groups

• US 6,492,756 B1
• Filed: 04/05/2001
• Issued: 12/10/2002
• Est. Priority Date: 04/05/2000
• Status: Expired due to Fees

• Current Assignee: Matra Manufacturing & Services SAS (Lagardère SA)
• Original Assignee: WaveCrest Laboratories LLC (Magna International Incorporated)
• Inventors: Maslov, Boris, Pyntikov, Alexander
• Primary Examiner(s): Le, Dang Dinh
• Application Number:
  US09/826,423
• Time in Patent Office: 614 Days
• Field of Search: 310/191, 310/209, 310/156.01, 310/156.03, 310/156.07, 310/156.12, 310/156.13, 310/156.15, 310/156.26, 310/156.33, 310/156.36, 310/156.37, 310/156.44, 310/156.48, 310/156.49, 310/156.51, 310/156.52, 310/156.54, 310/156.55, 310/156.59, 310/156.74, 310/254, 310/258, 310/259, 310/216, 310/218, 310/74
• US Class Current: 310/156.12
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0061 relating to electrical machines
• CPC Class Codes: B60L 50/20 using propulsion power generated by humans or animals
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B62M 6/40 Rider propelled cycles with auxiliary electric motor
• CPC Class Codes: B62M 6/45 Control or actuating devices therefor
• CPC Class Codes: B62M 7/12 with the engine beside or within the driven wheel
• CPC Class Codes: H02K 1/187 to inner stators
• CPC Class Codes: H02K 1/2791 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 1/30 using intermediate parts, e.g. spiders
• CPC Class Codes: H02K 21/18 : having horse-shoe armature cores with homopolar co-operation H02K21/20
• CPC Class Codes: H02K 21/227 : having an annular armature coil
• CPC Class Codes: H02K 29/06 : with position sensing devices H02K29/03 takes precedence
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A rotary direct current electric motor in which rotor and stator members are each configured as annular rings, concentric with respect to each other, about an axis of rotation. Either of the rotor or stator members is formed of groups of electromagnet pole pairs, the groups substantially equidistantly distributed along the angular extent of the annular ring, each of the groups comprising magnetic material magnetically isolated and separated from the other groups. The other member includes a plurality of permanent magnet poles substantially equidistantly distributed with alternating magnetic polarity along the angular extent of the radial air gap formed between the members, the permanent magnet poles having a discontinuous magnetic return path, thereby dividing the member into magnetically isolated groups of permanent magnet poles.

Claims

1. A rotary electric motor comprising:

a stator configured in the form of an annular ring of groups of electromagnet poles, the groups substantially equidistantly distributed along the angular extent of the annular ring, each of the groups comprising magnetic material magnetically isolated and separated from the other groups; and

an annular rotor, concentric with an axis of rotation and concentric with the annular stator to form a radial air gap therebetween, comprising a plurality of groups of permanent magnet poles, the rotor groups substantially equidistantly distributed along the angular extent of the air gap, the permanent magnet poles of each group having a common magnetic return path that is isolated from the magnetic return paths of adjoining permanent magnet pole groups;

wherein each group of stator electromagnet poles comprises windings that are switchably energized for driving electromotive interaction between the stator and rotor.

2. A rotary electric motor as recited in claim 1, wherein each rotor permanent magnet pole group comprises an even number of magnets that alternate in magnetic polarity.

3. A rotary electric motor as recited in claim 2, wherein the rotor comprises an even number of permanent magnet groups and the stator comprises an odd number of electromagnet groups.

4. A rotary electric motor as recited in claim 2 wherein the rotor poles in the rotor groups have pole faces separated by gaps substantially uniformly for all groups, the gaps being substantially equal to gaps between pole faces of adjacent groups.

5. A rotary electric motor as recited in claim 3, wherein all of the rotor groups contain the same number of poles and all the stator groups contain the same number of poles.

6. A rotary electric motor as recited in claim 5, wherein the number of poles in each rotor group is the same as the number of poles in each stator group.

7. A rotary electric motor as recited in claim 6, wherein the number of poles in each rotor group and stator group is two.

8. A rotary electric motor as recited in claim 6, wherein the number of poles in each rotor group and stator group is a multiple of two.

9. A rotary electric motor as recited in claim 6, wherein the number of poles in each rotor group and stator group is an odd multiple of two.

10. A rotary electric motor as recited in claim 1, further comprising a rotor position sensor, wherein signals for switching energization of the windings are generated in response to the sensor.

11. A rotary electric motor as recited in claim 10, wherein said position sensor comprises a resolver;

and said motor further comprises an encoder for generating said signals.

12. A rotary electric motor as recited in claim 1, wherein the angular distance between poles of each stator group is substantially uniform throughout the periphery of the stator and differs from the angular distance between stator poles of adjacent groups.

13. A rotary electric motor as recited in claim 12, wherein the angular distance between poles in each stator group is independent of the angular distance between adjacent permanent magnet poles of the rotor.

14. A rotary electric motor as recited in claim 13, wherein the angular distance between poles each stator group is different from the angular distance between adjacent permanent magnet poles of the rotor.

15. A rotary electric motor as recited in claim 1, wherein the stator poles have pole faces extending in substantially equal angular distance along the air gap and the rotor permanent magnet poles have pole faces extending in substantially equal angular distance along the air gap, the angular extent of the stator pole faces being different from the angular extent of the rotor pole faces.

16. A rotary electric motor as recited in claim 15, wherein the stator pole faces are separated by gaps, the gaps between adjacent stator pole faces within each group being substantially equal and different from the gaps between adjacent stator groups.

17. A rotary electric motor as recited in claim 16, wherein the rotor pole faces are separated by substantially uniform gaps throughout the angular extent of the rotor, the gaps between adjacent rotor pole faces being different from the gaps between adjacent stator pole faces within a stator group.

18. A rotary electric motor as recited in claim 1, wherein the rotor surrounds the stator.

19. A rotary electric motor as recited in claim 1, wherein each stator group is individually secured in the stator annular ring structure, thereby facilitating independent removal and replacement of an individual stator group.

20. A rotary electric motor as recited in claim 19, wherein said motor further comprises:

a plate member; and

a shaft member located at the axis of rotation;

wherein each of said stator groups is secured to said plate member at a spaced radial distance from the axis of rotation; and

said plate member is attached to said shaft member.

21. A rotary electric motor as recited in claim 20, wherein said spaced radial distance is greater than the radial distance between inner and outer boundary diameters of the stator annular ring.

22. A rotary electric motor as recited in claim 20, wherein the annular stator comprises an inner boundary at a first radial distance from the axis of rotation and an outer boundary at a second radial distance from the axis of rotation, and the radial distance between the inner and outer boundaries is less than said first radial distance.

23. A rotary electric motor as recited in claim 19, wherein said rotor further comprises an annular ring of nonmagnetic material, and said rotor groups are fixed to the inner surface of said ring of nonmagnetic material.

24. A rotary electric motor as recited in claim 23, wherein said motor further comprises a rotor housing, the rotor annular rotor being secured within the housing at a spaced radial distance from the axis of rotation, and the rotor housing is journalled for rotation about the shaft through bearings.

25. A rotary electric motor having a stator and a rotor, the motor comprising:

first and second annular ring members concentrically arranged about an axis of rotation and separated from each other by an radial air gap;

wherein

said first member comprises groups of electromagnet poles, the groups substantially equidistantly distributed along its annular ring, each of the groups comprising magnetic material magnetically and electrically isolated and separated from the other groups;

said second member comprises a plurality of groups of permanent magnet poles substantially equidistantly distributed with alternating magnetic polarity within each group, each group of permanent magnet poles having a common magnetic return path that is isolated and separated from the magnetic return path of adjacent permanent magnet groups; and

wherein each group of electromagnet poles comprises windings that are switchably energized for driving electromotive interaction between the first and second members, in accordance with a sequential, non-sequential, or random excitation scheme.

26. A rotary electric motor as recited in claim 25, wherein the rotor surrounds the stator.

27. A rotary electric motor as recited in claim 26, wherein the stator comprises said first annular ring member and the rotor comprises said second annular ring member.

28. A rotary electric motor as recited in claim 27, wherein the annular stator comprises an inner boundary at a first radial distance from the axis of rotation and an outer boundary at a second radial distance from the axis of rotation, and the radial distance between the inner and outer boundaries is less than said first radial distance.

29. A rotary electric motor as recited in claim 26, wherein the stator comprises said second annular ring member and the rotor comprises said first annular ring member.

30. A rotary electric motor as recited in claim 25, wherein said groups of electromagnet poles are spaced from each other by an angular distance that is different from spacing between adjacent permanent magnet groups.

31. A rotary electric motor as recited in claim 25, wherein the number of permanent magnet groups is an even number and the number electromagnet groups is an odd number.

32. A rotary electric motor as recited in claim 31, wherein all groups contain the same number of magnetic poles.