# US 12,009,717 B2 · Multi-tunnel electric machine

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- Number: US 12,009,717 B2
- Document ID: US12009717B2
- Status: Granted
- Kind: B2
- Application number: 17/962,076
- Filed: 2022-10-07
- Published: 2023-06-08
- Granted: 2024-06-11
- Earliest claimed: 2019-08-26
- Assignees: Linear Labs, Inc.
- Applicants: Linear Labs, Inc.
- Inventors: Fred E. Hunstable; Michael Van Steenburg; Andrei V. Popov
- Web page: https://patentgrep.com/patent/US12009717B2

## CPC

- H02K 3/47: Air-gap windings, i.e. iron-free windings
- H02K 1/02: characterised by the magnetic material
- H02K 1/146: {consisting of a generally annular yoke with salient poles}
- H02K 1/18: Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
- H02K 1/27: Rotor cores with permanent magnets
- H02K 3/522: {for generally annular cores with salient poles}
- H02K 11/30: Structural association with control circuits or drive circuits
- H02K 11/33: Drive circuits, e.g. power electronics (H02K11/38 takes precedence)
- H02K 15/095: by laying conductors around salient poles
- H02K 15/32: Manufacture of terminal arrangements; Connecting the terminals to external circuits
- H02K 16/02: Machines with one stator and two {or more} rotors
- H02K 21/12: with stationary armatures and rotating magnets
- H02K 21/145: {having an annular armature coil (with homopolar co-operation H02K21/20)}
- H02K 2201/03: Machines characterised by aspects of the air-gap between rotor and stator
- H02K 2201/12: Transversal flux machines
- H02K 2203/03: Machines characterised by the wiring boards, i.e. printed circuit boards or similar structures for connecting the winding terminations
- H02K 2203/12: Machines characterised by the bobbins for supporting the windings
- H02K 2211/03: Machines characterised by circuit boards, e.g. pcb
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

Disclosed are various embodiments for an electric machine where the stator is a coil assembly and the rotor is a magnetic toroidal cylindrical tunnel or where the rotor is a coil assembly and the stator is a magnetic toroidal cylindrical tunnel.

## Claims

### Claim 1

A rotary electric machine comprising:
a magnetic toroidal cylinder radially arranged about a motor axis and comprising:
a first magnetic tunnel segment comprising a first set of magnetic elements defining a first magnetic polarity configuration; and
a second magnetic tunnel segment:
arranged adjacent the first magnetic tunnel segment; and
comprising a second set of magnetic elements defining a second magnetic polarity configuration, opposite the first magnetic polarity configuration; and
a coil assembly positioned within the magnetic toroidal cylinder, the coil assembly comprising:
a yoke;
a set of coil modules radially positioned about the motor axis and coupled to the yoke, wherein each coil module, in the set of coil modules, comprises;
a coil winding;
an electrical interface module:
positioned radially adjacent to an inside face of the coil winding and electrically coupled to the coil winding; and
comprising a connector electrically coupling the coil winding to a controller;
a stator pole:
arranged on the circular yoke adjacent to the coil winding;
comprising a vertical element, an outer face, an inner face, a side face, and an opposing side face; and
defining a recess arranged about the stator pole and configured to partially enclose adjacent coil windings and the electrical interface module.

### Claim 2 (depends on 1)

The rotary electric machine of claim 1:
wherein the first set of magnetic elements comprises:
a first inner radial magnetic wall;
a first outer radial magnetic wall;
a first upper axial magnetic wall; and
a first lower axial magnetic wall, cooperating with the first inner radial magnetic wall, the first outer radial magnetic wall, and the first upper axial magnetic wall to form the first magnetic tunnel segment enclosing the set of coil modules; and
wherein the second set of magnetic elements comprises:
a second inner radial magnetic wall;
a second outer radial magnetic wall;
a second upper axial magnetic wall; and
a second lower axial magnetic wall, cooperating with the second inner radial magnetic wall, the second outer radial magnetic wall, and the second upper axial magnetic wall to form the second magnetic tunnel segment, adjacent the first magnetic tunnel segment, and enclosing the set of coil modules.

### Claim 3 (depends on 2)

The rotary electric machine of claim 2:
wherein the first set of magnetic elements comprises a NNNN magnetic polarity configuration; and
wherein the second set of magnetic elements comprises a SSSS magnetic polarity configuration.

### Claim 4 (depends on 1)

The rotary electric machine of claim 1:
wherein each coil module, in the set of coil modules, comprises an alignment feature arranged on an inner side of the coil module; and
further comprising an alignment ring comprising a set of spokes coupling the alignment feature, of each coil module in the set of coil modules, to locate the alignment ring radially enclosed within the set of coil modules.

### Claim 5

A rotary electric machine comprising:
a set of coil modules:
radially arranged about a motor axis;
defining an inner radial facet, an outer radial facet, a first axial facet, and a second axial facet opposite the first axial facet; and
comprising a first coil module comprising:
a first coil winding;
a first electrical interface module arranged on an inner radial side of the first coil winding and electrically coupled to the first coil winding; and
a first connector coupled to the first electrical interface module and extending from the inner radial side of the first coil winding;
a set of magnetic elements:
encompassing the inner radial facet, the outer radial facet, the first axial facet, and the second axial facet of the set of coil modules;
forming a magnetic toroidal cylinder about the motor axis; and
configured to generate a flux density distribution focused toward the set of coil modules; and
a controller:
electrically coupled to the first connector of the first coil module; and
configured to drive current through the set of coil modules to generate a toroidal magnetic field tunnel configured to sequentially and magnetically couple the set of magnetic elements.

### Claim 6 (depends on 5)

The rotary electric machine of claim 5, wherein the magnetic toroidal cylinder comprises:
a first magnetic tunnel segment comprising a first subset of magnetic elements, in the set of magnetic elements, defining a first magnetic polarity configuration; and
a second magnetic tunnel segment:
arranged adjacent the first magnetic tunnel segment; and
comprising a second subset of magnetic elements, in the set of magnetic elements, defining a second magnetic polarity configuration opposite the first magnetic polarity configuration.

### Claim 7 (depends on 5)

The rotary electric machine of claim 5, wherein the set of magnetic elements comprises:
a first subset of magnetic elements defining a NNNN magnetic polarity configuration and comprising:
a first inner radial magnetic wall;
a first outer radial magnetic wall;
a first upper axial magnetic wall; and
a first lower axial magnetic wall, cooperating with the first inner radial magnetic wall, the first outer radial magnetic wall, and the first upper axial magnetic wall to form the first magnetic tunnel segment enclosing the set of coil modules; and
a second subset of magnetic elements defining a SSSS magnetic polarity configuration and comprising:
a second inner radial magnetic wall;
a second outer radial magnetic wall;
a second upper axial magnetic wall; and
a second lower axial magnetic wall, cooperating with the second inner radial magnetic wall, the second outer radial magnetic wall, and the second upper axial magnetic wall to form the second magnetic tunnel segment, adjacent the first magnetic tunnel segment, enclosing the set of coil modules.

### Claim 8 (depends on 5)

The rotary electric machine of claim 5:
wherein the first coil module further comprises:
a first pole structure tapering toward the motor axis; and
a second pole structure:
tapering toward the motor axis;
radially offset the first pole structure to define a radial interstice between the first pole structure and the second pole structure; and
cooperating with the first pole structure to generate a three-dimensional flux path between the first pole structure and the second pole structure; and
wherein the first coil winding is arranged in the radial interstice between the first pole structure and the second pole structure.

### Claim 9 (depends on 8)

The rotary electric machine of claim 8:
wherein the first pole structure comprises:
a first set of flat magnetic elements arranged to form a first crescent shape; and
a second set of flat magnetic elements arranged to form a second crescent shape coupled to the first crescent shape to form a first radial slot within the first pole structure;
wherein the second pole structure comprises:
a third set of flat magnetic elements arranged to form a third crescent shape; and
a fourth set of flat magnetic elements arranged to form a fourth crescent shape coupled to the third crescent shape to form a second radial slot within the second pole structure in radial alignment with the first radial slot of the first pole structure; and
further comprising a cylindrical yoke arranged about the motor axis and located within the first radial slot of the first pole structure and the second radial slot of the second pole structure.

### Claim 10 (depends on 8)

The rotary electric machine of claim 8:
wherein the first pole structure comprises:
a first set of magnetic elements arranged to form a first rectangular wedge tapered toward the motor axis; and
a first radial slot arranged on a center of the first rectangular wedge;
wherein the second pole structure comprises:
a second set of magnetic elements arranged to form a second rectangular wedge, radially offset the first rectangular wedge, tapered toward the motor axis; and
a second radial slot arranged on a center of the second rectangular wedge and radially aligned to the first radial slot; and
further comprising a cylindrical yoke arranged about the motor axis and located within the first radial slot of the first pole structure and the second radial slot of the second pole structure.

### Claim 11 (depends on 5)

The rotary electric machine of claim 5:
wherein the first coil module further comprises:
a first pole structure:
arranged adjacent a first side of the first coil winding;
comprising a first rectangular wedge formed of a ferrous material tapering toward the motor axis; and
defining a first recess arranged on a lateral side of the first pole structure; and
a second pole structure:
radially offset the first pole structure;
arranged adjacent a second side, opposite the first side, of the first coil winding;
comprising a second rectangular wedge formed of the ferrous material tapering toward the motor axis; and
defining a second recess arranged on a lateral side of the second pole structure facing the first recess of the first pole structure; and
wherein the first coil winding is nested within the first recess of the first pole structure and the second recess of the second pole structure to locate the first electrical interface module on the inner radial side of the first coil winding.

### Claim 12 (depends on 11)

The rotary electric machine of claim 11:
wherein the first pole structure further comprises a first slot arranged on an inner radial side of the first pole structure and adjacent a first side of the first connector extending from the first electrical interface module;
wherein the second pole structure comprises a second slot arranged on an inner radial side of the second pole structure and adjacent a second side, opposite the first side, of the first connector extending from the first electrical interface module; and
further comprising:
an alignment ring comprising a set of spokes arranged radially about the alignment ring coupling the first slot of the first pole structure and the second slot of the second pole structure to locate the alignment ring radially enclosed within the set of coil modules; and
a shaft coupled to the alignment ring and arranged in alignment with the motor axis.

### Claim 13 (depends on 11)

The rotary electric machine of claim 11:
wherein the first coil module further comprises:
the first pole structure defining a first aperture;
the second pole structure defining a second aperture in radial alignment with the first aperture; and
a first bobbin:
interposed between the first pole structure and the second pole structure;
comprising the first coil winding wound about the first bobbin; and
defining a third aperture in radial alignment with the first aperture and the second aperture; and
further comprising a cylindrical yoke arranged about the motor axis and extending through the first aperture, second aperture, and the third aperture.

### Claim 14 (depends on 5)

The rotary electric machine of claim 5, further comprising a cylindrical yoke arranged about the motor axis and coupled to the set of coil modules, the cylindrical yoke formed of a ferromagnetic open cell foam material infused with a non-ferrous metal matrix.

### Claim 15 (depends on 5)

The rotary electric machine of claim 5, further comprising a back iron circuit comprising:
a first outer plate:
defining a first set of outer slots; and
comprising a first subset of axial magnetic elements, in the set of magnetic elements, arranged at the first set of outer slots and facing the first axial facet of the set of coil modules;
a second outer plate:
arranged opposite the first outer plate;
defining a second set of outer slots; and
comprising a second subset of axial magnetic elements, in the set of magnetic elements, arranged at the second set of outer slots and facing the second axial facet of the set of coil modules; and
an outer radial wall:
interposed between the first outer plate and the second outer plate;
defining a set of outer radial slots arranged about the outer radial wall; and
comprising a subset of outer radial magnetic elements, in the set of magnetic elements, arranged at the set of outer radial slots and facing the outer radial facet of the set of coil modules.

### Claim 16 (depends on 15)

The rotary electric machine of claim 15:
wherein the back iron circuit further comprises an inner rotor core:
arranged within an inner radius of the set of coil modules;
defining a set of inner slots arranged about the inner rotor core;
comprising a subset of inner radial magnetic elements, in the set of magnetic elements, arranged at the set of inner slots and facing the inner radial facet of the set of coil modules; and
cooperating with the first outer plate, second outer plate, and outer radial wall to form a cylindrical magnetic tunnel enveloping the set of stator pole assemblies; and
further comprising a shaft coupled to the inner rotor core and arranged in alignment with the motor axis.

### Claim 17 (depends on 5)

The rotary electric machine of claim 5, wherein the set of magnetic elements comprises:
a first subset of axial magnetic walls arranged in a radial pattern about the first axial facet of the set of coil modules;
a second subset of axial magnetic walls arranged in a radial pattern about the second axial facet, opposite the first axial facet, of the set of coil modules;
a subset of inner radial magnetic walls arranged in a radial pattern about the inner radial facet of the set of coil modules; and
a subset of outer radial magnetic walls arranged in a radial pattern about the outer radial facet of the set of coil modules and cooperating with the first subset of axial magnetic walls, the second subset of axial magnetic walls, and the subset of inner radial magnetic walls to form a cylindrical magnetic tunnel enveloping the set of coil modules.

### Claim 18 (depends on 5)

The rotary electric machine of claim 5, further comprising:
a stator yoke comprising:
a first yoke segment extending radially about the motor axis; and
a second yoke segment:
coupled at a first end and a second end of the first yoke segment;
extending radially about the motor axis; and
cooperating with the first yoke segment to define a cylindrical yoke for the set of stator pole assemblies; and
a set of stator pole assemblies comprising:
a first subset of stator pole assemblies radially arranged about the first yoke segment to define a first set of radial interstices; and
a second subset of stator pole assemblies:
radially arranged about the second yoke segment to define a second set of radial interstices; and
cooperating with the first subset of stator pole assemblies to form a ring stator core of circumferential stator poles and radial interstices.

### Claim 19

A system for a rotary electric machine comprising:
a set of coil modules:
radially arranged about a motor axis;
comprising a first coil module comprising:
a first coil winding;
a first electrical interface module arranged on an inner radial side of the first coil winding and electrically coupled to the first coil winding; and
a first connector coupled to the first electrical interface module and extending from the inner radial side of the first coil winding;
a set of magnetic elements arranged about the motor axis and forming a magnetic toroidal cylinder enclosing the set of coil modules; and
a controller:
arranged within an inner radius of the set of coil modules and electrically coupled to the first connector of the first coil module; and
configured to drive current through the set of coil modules to generate a toroidal magnetic field tunnel configured to sequentially and magnetically couple the set of magnetic elements.

### Claim 20 (depends on 19)

The rotary electric machine of claim 19, wherein the set of magnetic elements:
encompasses an inner radial facet, an outer radial facet, a first axial facet, and a second axial facet of the set of coil modules; and
comprises:
a first magnetic tunnel segment comprising a first subset of magnetic elements, in the set of magnetic elements, defining a first magnetic polarity configuration; and
a second magnetic tunnel segment:
arranged adjacent the first magnetic tunnel segment; and
comprising a second subset of magnetic elements, in the set of magnetic elements, defining a second magnetic polarity configuration opposite the first magnetic polarity configuration.