Electric machine having segmented stator

• US 20070296298A1
• Filed: 05/07/2007
• Published: 12/27/2007
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: Robert M. Jones
• Original Assignee: Robert M. Jones
• Inventors: Lisiecki, Joseph, Jones, Robert
• Granted Patent: US 7,592,728 B2
• Time in Patent Office: Days
• US Class Current: 310/179
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 16/00 Machines with more than one rotor or stator machines for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts H02K51/00; permanent magnet machines with multiple rotors or stators relatively rotated for vectorially combining the excitation fields or the armature voltages H02K21/029
• CPC Class Codes: H02K 21/16 having annular armature cores with salient poles with homopolar co-operation H02K21/20
• CPC Class Codes: H02K 2213/12 Machines characterised by the modularity of some components
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02K 3/38 around winding heads, equalising connectors, or connections thereto
• CPC Class Codes: H02K 5/04 Casings or enclosures characterised by the shape, form or construction thereof
• CPC Class Codes: H02K 5/18 with ribs or fins for improving heat transfer
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132

Abstract

An electric machine, such as a brushless direct current motor, includes a number of stator formed as stator sections. The stator sections are longitudinally offset from each other along a common central axis of the electric machine. The stator sections are magnetically independent of one another, but are electrically driven with offset phases typically in a manner similar to a standard multi-phase motor. The stator sections may be further offset with one another in radial position. The structure of the stator sections provides advantages in terms of efficiency, power consumption, torque, and thermal performance, and can be especially advantageous where a battery is used to power the motor, such as in portable hand tools or driving motors for vehicles.

Claims

1. An electric machine comprising:

a cylindrical stator comprising a plurality of stator sections, each stator section having an associated winding that is magnetically independent of the windings of the other stators, the winding being wound around an inner periphery of each of the plurality of the cylindrical stator sections;

a rotor disposed within the cylindrical stator; and

the plurality of stator sections being longitudinally offset from each other along a common central axis of the electric machine.

2. An electric machine according to claim 1, wherein the rotor comprises a plurality of rotor sections, each being magnetically independent of the other rotor sections.

3. An electric machine according to claim 2, further comprising:

a driving circuit that provides a driving signal to each stator section, the driving signal relating to each of the stator sections having an electrical phase difference with respect to the driving signals for the other stator sections.

4. An electric machine according to claim 2, wherein each of the plurality of rotor sections electromagnetically interacts with a corresponding one of the plurality of stator sections.

5. An electric machine as in claim 1, wherein the stator sections are radially offset from each other.

6. An electric machine as in claim 1, wherein the stator sections are wire wound.

7. An electric machine as in claim 1, wherein the stator sections comprise blade sections.

8. An electric machine according to claim 2, wherein the rotor comprises a plurality of permanent magnets with at least one magnet in one rotor section being radially offset from another permanent magnet in another rotor section.

9. An electric machine according to claim 2, wherein the rotor comprises a plurality of permanent magnets in each of the rotor sections, the plurality of permanent magnets in at least one of the rotor sections having a different magnetic polarity sequence from the plurality of permanent magnets in another of the rotor sections.

37. The electric machine of claim 1, wherein distance between the winding and rotor is minimized, and wherein the winding is wound around the inner periphery of each of the plurality of cylindrical stator sections and around a plurality of tines with the tines having a predetermined size to maximize the electromagnetic flux between the winding and the rotor.

10. A stator comprising:

a first stator portion;

a second stator portion;

a third stator portion; and

each of the first through third stator portions including an associated winding being magnetically independent relative to the remainder of the first through third stator portions, the winding being wound around a plurality of tines, the plurality of tines being located in an inner surface of each of the first through third stator portions.

11. The stator of claim 10, wherein each of the first through third stator portions are longitudinally offset from one another along a common central axis thereof.

12. The stator of claim 10, wherein each of the first through third stator portions are radially offset from one another.

13. The stator claim 12, wherein the first stator portion is radially offset from the second stator portion by about ten degrees.

14. The stator of claim 12, wherein the second stator portion is radially offset from the third stator portion by about ten degrees.

15. The stator of claim 10, wherein each of the first through third stator portions is generally associated with an operating phase of an electric motor.

16. The stator of claim 10, further comprising at least three tines for receiving the winding.

17. The stator of claim 16, wherein the tines are externally located relative to an outer surface of the first through third stator sections.

18. The stator of claim 10, wherein at least one of the first through third stator sections is generally cylindrical.

19. The stator of claim 10, wherein at least one of the first through third stator portions comprises a back iron.

20. The stator of claim 10, wherein at least one of the first through third stator portions comprises a plurality of laminated disks.

21. The stator of claim 10, wherein the first through third stator sections are all generally cylindrically shaped.

22. A stator comprising:

a plurality of stator portions;

a winding associated with each of the plurality of stator portions, the winding being magnetically independent relative to the winding of the remaining plurality of stator portions; and

the winding being wound around a plurality of tines being located around an inner surface of each of the plurality of stator portions.

23. The stator of claim 22, wherein each winding of the plurality of stator portions is electrically and mechanically independent relative to the other stator portions.

24. The stator of claim 22, wherein each of the plurality of stator portions serves as a single phase of an electric motor.

25. The stator of claim 22, wherein each of the plurality of stator portions is longitudinally offset from one another along a central axis thereof.

26. The stator of claim 22, wherein each of the plurality of stator portions is radially offset from one another.

27. The stator of claim 22, further comprising at least one blade being provided to provide connectivity to create the associated winding.

28. The stator of claim 22, further comprising at least one insulating disk being disposed between at least two of the plurality of stator portions.

29. The stator of claim 22, wherein at least one of the plurality of stator portions is used for one function of an electric motor, while another of the plurality of stator portion is used for a different function.

30. The stator of claim 29, wherein at least one function is selected from the group consisting of power, energy generation, and braking.

31. The stator of claim 22, further comprising at least a first stator portion, a second stator portion, and a third stator portion with at least two stator portions being offset from one another.

32. The stator of claim 31, further comprising an insulating member being disposed between at least the first stator portion and the second stator portion.

33. The stator of claim 32, further comprising a second insulating member between the second stator portion and the third stator portion.

34. The stator of claim 31, wherein the radial offset is about ten degrees between the at least two stator portions.

35. The stator of claim 31, wherein the radial offset is about twenty degrees between the at least two stator portions.

36. The stator of claim 22, wherein each of the plurality of stator portions is manufactured from a plurality of laminated disks.