Flux concentrator for ironless motors

Patent metadata

Field	Value
Publication number	US-9270154-B2
Application number	US-56571809-A
Country	US
Kind code	B2
Filing date	Sep 23, 2009
Priority date	Sep 23, 2008
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

In one possible embodiment, a magnet array for a motor is provided which has an array of permanent magnets being arranged such that flux from the permanent magnets reinforce on one side of the array and substantially cancel on an opposite side of the array, the array further includes flux concentrators located at poles on the reinforcing side of the array.

First claim

What is claimed is:

1. A magnet array for a motor comprising a first array of permanent magnets being arranged such that flux from the permanent magnets substantially cancels on an opposite side of the first array, the array further comprising flux concentrators located at poles on a reinforcing side of the first array, wherein the first array is positioned opposite a second array of permanent magnets with an ironless winding therebetween, the ironless winding being a winding without an iron core associated therewith, the second array comprising flux concentrators located at poles on a reinforcing side of the second array such that the flux from the permanent magnets of the first and second arrays concentrates through respective flux concentrators before extending and mutually reinforcing across the winding, the second array being arranged such that the flux from the permanent magnets of the second array substantially cancels on a side of the second array opposite the winding, wherein each of the flux concentrators on the reinforcing side of the first array and each of the flux concentrators on the reinforcing side of the second array have substantially a same width along their thicknesses as a respective permanent magnet pole therebehind, and wherein the ironless winding comprises conductor bundles comprising a generally rectangular cross-section arranged such that a long side of the generally rectangular cross-section is transverse to a direction of magnetic field lines between the flux concentrators of first and second arrays.

2. The magnet array of claim 1 , wherein the flux concentrators are recessed into the first array.

3. The magnet array of claim 2 , wherein an exterior surface of the flux concentrators are aligned with exterior surfaces of adjacent magnets located along the reinforcing sides.

4. The magnet array of claim 1 , wherein the flux concentrators comprise a magnetic material having a higher flux density than the magnets.

5. The magnet array of claim 1 , wherein the first array comprises back magnets behind the flux concentrators on a side opposite the reinforcing side of the first array.

6. The magnet array of claim 1 , wherein the flux concentrators are placed into the array such that each flux concentrator has a back magnet and is located between adjacent side magnets.

7. The magnet array of claim 6 , wherein magnetic moments of magnets adjacent to a flux concentrator either all point in a direction generally toward the adjacent flux concentrator or all point in a direction generally away from the adjacent flux concentrator.

8. The magnet array of claim 6 , wherein the flux concentrators comprise a magnetic material having a higher flux density than the magnets.

9. The magnet array of claim 8 , wherein the flux concentrators comprise iron.

10. The magnet array of claim 1 , wherein the flux concentrators comprise iron.

11. A motor comprising:
a) a rotor comprising opposing inner and outer rotors;
b) a stator comprising an ironless winding located between the inner and outer rotors, the ironless winding being a winding without an iron core associated therewith;
c) the inner and the outer rotors each comprising an array of permanent magnets arranged such that flux from the permanent magnets reinforce across the stator and substantially cancel on sides of the arrays opposite the stator, each of the arrays further comprising flux concentrators located at poles on the stator side of the array such that the flux from permanent magnets of the inner rotor concentrates through flux concentrators of the inner rotor and the flux from the permanent magnets of the outer rotor concentrates through the flux concentrators of the outer rotor so that concentrated flux through the flux concentrators of the inner rotor and concentrated flux through the flux concentrators of the outer rotor mutually reinforce across the winding, wherein the flux concentrators of the inner rotor and the flux concentrators of the outer rotor have substantially a same width along their thicknesses as a respective permanent magnet pole therebehind; and
d) wherein the ironless winding comprises conductor bundles comprising an elongated cross-section arranged such that a long side of the elongated cross-section is transverse to a direction of magnetic field lines between the inner rotor and the outer rotor.

12. The motor of claim 11 , wherein the flux concentrators are recessed into the arrays.

13. The motor of claim 12 , wherein an exterior surface of the flux concentrators are aligned with exterior surfaces of adjacent magnets located along the stator side.

14. The motor of claim 11 , wherein the flux concentrators comprise a magnetic material having a higher flux density than the magnets.

15. The motor of claim 11 , wherein each array comprises back magnets behind the flux concentrators on a side opposite the stator.

16. The motor of claim 11 , wherein the flux concentrators are placed into the array such that each flux concentrator has a back magnet and is located between adjacent side magnets.

17. The motor of claim 16 , wherein magnetic moments of magnets adjacent to a flux concentrator either all point in a direction generally toward the adjacent flux concentrator or all point in a direction generally away from the adjacent flux concentrator.

18. The motor of claim 16 , wherein the flux concentrators comprise a magnetic material having a higher flux density than the magnets.

19. The motor of claim 18 , wherein the flux concentrators comprise iron.

20. The motor of claim 11 , wherein the flux concentrators comprise iron.

21. A motor comprising:
a) an inner rotor and an outer rotor;
b) a stator comprising an ironless winding between the inner rotor and the outer rotor, the ironless winding being a winding without an iron core associated therewith;
c) the inner rotor and the outer rotor each comprising an array of permanent magnets being arranged such that flux from the permanent magnets reinforce on a side of the array facing the stator and substantially cancel on a side of the array opposite the stator, each array further comprising flux concentrators interposed between poles of the permanent magnets on the reinforcing side of the array and the stator, wherein the flux concentrators of the inner rotor array and the flux concentrators of the outer rotor array have substantially a same width along their thicknesses as a respective permanent magnet pole therebehind; and
d) wherein the winding comprises conductor bundles comprising an elongated cross-section arranged such that a long side of the elongated cross-section is transverse to a direction of magnetic field lines between the inner rotor array and the outer rotor array.

22. The motor of claim 21 , wherein the flux concentrators are recessed within each array.

23. The motor of claim 22 , wherein exterior surfaces of the flux concentrators are aligned with exterior surfaces of adjacent magnets located along the stator side.

24. The motor of claim 21 , wherein the flux concentrators comprise a magnetic material having a higher flux density than the magnets.

25. The motor of claim 21 , wherein the array comprises back magnets behind the flux concentrators opposite the stator sides of the arrays.

26. The motor of claim 21 , wherein the flux concentrators are placed into the arrays such that each flux concentrator has a back magnet and is located between adjacent side magnet

Assignees

• Hibbs Bart Dean
• Phan Bang Xuan
• Aerovironment Inc

Inventors

• Hibbs Bart Dean
• Phan Bang Xuan

Classifications

• H02K3/02

  Windings characterised by the conductor material · CPC title

• H02K7/1838

  Generators mounted in a nacelle or similar structure of a horizontal axis wind turbine · CPC title

• H02K3/28

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title

• H02K1/2706 Primary

  Inner rotors · CPC title

• H02K21/12 Primary

  with stationary armatures and rotating magnets · CPC title