Induction machines without permanent magnets

Patent metadata

Field	Value
Publication number	US-12095394-B2
Application number	US-202117562570-A
Country	US
Kind code	B2
Filing date	Dec 27, 2021
Priority date	Jun 26, 2019
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

Disclosed are various embodiments for an induction machine having a rotor comprising a plurality of rotor core assemblies configured to form a toroidal magnetic torque tunnel having at least a first inductive tunnel segment and a second inductive tunnel segment and a stator having a plurality of coils configured to form a coil winding assembly, the coil winding assembly positioned within the toroidal magnetic torque tunnel, such that at least one of the plurality of coils is surrounded by the first inductive tunnel segment or the second inductive tunnel segment, alternatively the rotor may be the coil winding assembly and the stator may be the toroidal magnetic torque tunnel.

First claim

What is claimed is:

1. An induction machine comprising:
a toroidal cylinder comprising;
an inner rotor core coupled to an inner cage, the inner cage comprising a first set of conductive bars radially spaced about a central longitudinal axis of the induction machine to form an inner rotor core assembly, and the first set of conductive bars are coupled to a first inner shorting ring and a second inner shorting ring;
a first axial rotor core coupled to a first set of axial spokes to form a first axial rotor core assembly, the first set of axial spokes comprising a second set of conductive bars coupled to, and radiating from, the first inner shorting ring;
a second axial rotor core coupled to a second set of axial spokes to form a second axial rotor core assembly, the second set of axial spokes comprising a third set of conductive bars coupled to, and radiating from, the second inner shorting ring, and the rotor core assemblies forming a three sided magnetic torque tunnel comprising a first inductive tunnel segment and a second inductive tunnel segment; and

a coil winding assembly arranged within the toroidal cylinder, the coil winding assembly comprising a set of coils, and the first inductive tunnel segment surrounding the set of coils.

2. The induction machine of claim 1 :
wherein the toroidal cylinder further comprises an outer rotor core coupled to an outer rotor cage to form an outer rotor assembly, the outer rotor cage comprising a fourth set of conductive bars radially spaced from the central longitudinal axis of the induction machine;
wherein the fourth set of conductive bars are coupled to a first outer shorting ring and a second outer shorting ring; and
wherein the first set of axial spokes are coupled to the first outer shorting ring and the second set of axial spokes are coupled to the second outer shorting ring, the rotor core assemblies forming a four sided magnetic torque tunnel comprising the first inductive tunnel segment and the second inductive tunnel segment.

3. The induction machine of claim 2 , wherein a quantity of conductive bars, in the first set of conductive bars, in the inner cage is different from a quantity of conductive bars, in the fourth set of conductive bars, in the outer rotor cage.

4. The induction machine of claim 2 , wherein the outer rotor assembly and the coil winding assembly are configured to minimize an air gap between the outer rotor assembly and the coil winding assembly.

5. The induction machine of claim 2 , wherein the outer rotor assembly defines, at least in part, a transverse slot, the transverse slot configured to support the coil winding assembly to pass through the outer rotor assembly.

6. The induction machine of claim 2 , wherein an outer edge of the first axial rotor assembly and a first end of the outer rotor core assembly cooperate to define a transverse slot.

7. The induction machine of claim 2 , wherein a longitudinal length of an inner face of the inner rotor core assembly is longer than a radial length of an inner face of the first axial rotor core assembly.

8. The induction machine of claim 1 , wherein a radial length of an inner face of the first axial rotor core assembly is longer than a longitudinal length of an inner face of the inner rotor core assembly.

9. The induction machine of claim 1 , wherein the rotor core comprises laminated strips of grain-oriented electrical steel coated with an oxide layer.

10. The induction machine of claim 1 , wherein the rotor core comprises an isotropic ferromagnetic material.

11. The induction machine of claim 1 , wherein the rotor core comprises an isotropic ferromagnetic material, the isotropic ferromagnetic material formed of a ferromagnetic open cell metal foam material comprising a porosity between 75% and about 95% by volume, and infused with a structural support matrix made of thermoset or a thermoplastic resin.

12. The induction machine of claim 1 , wherein the first set of conductive bars, the second set of conductive bars, and the third set of conductive bars defines a profile tapered with respect to depth.

13. A method of producing electric power with an induction machine comprising:
positioning a toroidal cylinder about a central longitudinal axis of the induction machine, the toroidal cylinder defined by:
an inner rotor core coupled to an inner cage, the inner cage comprising a first set of conductive bars radially spaced about the central longitudinal axis of the induction machine to form an inner rotor core assembly, the first set of conductive bars are coupled to a first inner shorting ring and a second inner shorting ring;
a first axial rotor core coupled to a first set of axial spokes to form a first axial rotor core assembly, the first set of axial spokes comprising a second set of conductive bars coupled to, and radiating from, the first inner shorting ring;
a second axial rotor core couple to a second set of axial spokes to form a second axial rotor core assembly, the second set of axial spokes comprising a third set of conductive bars coupled to, and radiating from, the second inner shorting ring, the rotor core assemblies forming a three sided magnetic torque tunnel comprising a first inductive tunnel segment and a second inductive tunnel segment, and the rotor core assemblies configured to rotate about the central longitudinal axis;

positioning a coil winding assembly within the toroidal cylinder about the central longitudinal axis within a rotational path of the rotor core assemblies, the coil winding assembly comprising a set of coils, the first inductive tunnel segment surrounding of the plurality of coils; and
applying current to the setof coils in a sequence that continuously impacts torque to turn the rotor core assemblies in a target direction, relative to the coil winding assembly.

14. The method of claim 13 :
wherein the toroidal cylinder further comprises an outer rotor core coupled to an outer rotor cage to form an outer rotor assembly, the outer rotor cage comprising a fourth set of conductive bars radially spaced about the central longitudinal axis of the induction machine;
wherein the fourth plurality of conductive bars are coupled to a first outer shorting ring and a second outer shorting ring; and
wherein the first set of axial spokes are coupled to the first outer shorting ring and the second set of axial spokes are coupled to the second outer shorting ring, the rotor core assemblies forming a four sided magnetic torque tunnel comprising the first inductive tunnel segment and the second inductive tunnel segment.

15. The method of claim 14 , wherein the outer rotor assembly and the coil winding assembly are configured to minimize an air gap between the outer rotor assembly and the coil winding assembly.

16. The method of claim 14 , wherein a longitudinal length of an inner face of the inner rotor core assembly is longer than a radial length of an inner face of the first axial rotor core assembly.

17. The method of claim 14 , wherein the outer rotor core assembly and the coil winding assembly are configured to minimize an air gap between the outer rotor core assembly and the coil winding assembly.

18. The method of claim 13 , wherein the sequence that continuously impacts torque is synchronized to the rotation of the rotor core assembles.

19. The method of claim 13 , wherein a radial length of an inner face of the first axial rotor core assembly is longer than a longitudinal length of an inner face of the inner rotor core assembly.

20. The method of claim 13 , wherein

Assignees

• Linear Labs Inc

Inventors

• Popov Andrei
• Van Steenburg Michael
• Hunstable Fred

Classifications

• H02K17/20

  having deep-bar rotors · CPC title

• H02K17/16

  having rotors with internally short-circuited windings, e.g. cage rotors · CPC title

• H02K2201/12

  Transversal flux machines · CPC title

• H02K16/02

  Machines with one stator and two {or more} rotors · CPC title

• H02K1/145

  having an annular coil, e.g. of the claw-pole type · CPC title