# US 12,003,152 B2 · Dual rotor electrical machines

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- Number: US 12,003,152 B2
- Document ID: US12003152B2
- Status: Granted
- Kind: B2
- Application number: 18/106,429
- Filed: 2023-02-06
- Published: 2023-06-15
- Granted: 2024-06-04
- Earliest claimed: 2016-03-30
- Assignees: Advanced Magnet Lab, Inc.
- Applicants: Advanced Magnet Lab, Inc.
- Inventors: Rainer Meinke; Shashikant Manikonda
- Web page: https://patentgrep.com/patent/US12003152B2

## CPC

- H02K 16/025: {with rotors and moving stators connected in a cascade (cascade arrangement of an asynchronous motor with another dynamo-electric motor or converter H02K17/34)}
- B60K 7/00: Disposition of motor in, or adjacent to, traction wheel
- H01F 1/0576: {pressed, e.g. hot working}
- H01F 41/0266: {Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11)}
- H01F 41/0273: {Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003)}
- H02K 1/27: Rotor cores with permanent magnets
- H02K 1/278: Surface mounted magnets; Inset magnets
- H02K 1/2783: with magnets arranged in Halbach arrays
- H02K 1/2792: with magnets arranged in Halbach arrays
- H02K 3/28: Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32)
- H02K 3/42: Means for preventing or reducing eddy-current losses in the winding heads, e.g. by shielding
- H02K 15/03: having permanent magnets
- H02K 16/02: Machines with one stator and two {or more} rotors
- H02K 21/12: with stationary armatures and rotating magnets
- B22F 9/04: starting from solid material, e.g. by crushing, grinding or milling ({C22C1/1084 takes precedence}; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C)
- H02K 1/2786: Outer rotors
- H02K 2201/03: Machines characterised by aspects of the air-gap between rotor and stator
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER

## Abstract

A dual-rotor machine comprising a dual rotor support structure rotatably connected to a frame. A stationary stator is disposed between the rotors and is fixed to the frame. An inner rotor and outer rotor, each comprising a permanent magnet Halbach array, are coaxially disposed with the stator and are rotable about the stator. In this configuration, the inner rotor channels its magnetic flux to its outside, while the outer rotor channels its magnetic flux to its inside. The magnetic flux density at the stator for the dual-rotor machine can be as high as 2 Tesla or higher for high-grade neodymium-iron-boron permanent magnet material, and the stored magnetic energy for conversion to mechanical or electrical energy available to the stator may be at least 0.5 kJ/m. The rotor Halbach arrays may comprise monolithic permanent magnets with continuously variable magnetic field direction.

## Claims

### Claim 1

A dual-rotor machine, comprising:
a frame;
a cylindrically shaped inner rotor having an outside diameter and a longitudinal axis, said inner rotor comprising a first Halbach permanent magnet array;
a cylindrically shaped outer rotor having an inside diameter and a longitudinal axis, said outer rotor comprising a second Halbach permanent magnet array;
and a cylindrically shaped stator having an inside diameter, an outside diameter, and a longitudinal axis, said stator comprising a magnetic coil;
wherein said stator is affixed to said frame; and
wherein said inner rotor, said outer rotor, and said stator are coaxially disposed forming a common axis for all of them, said inner rotor and said outer rotor being attached to one another, or attached to a common structure, and are rotably attached to said frame either directly or through a structure;
wherein said inner rotor outer diameter is less than said stator inside diameter, forming an air gap between them, and said outer rotor inside diameter is greater than said stator outside diameter, forming an air gap between them;
wherein said inner rotor and said outer rotor are able to rotate around said stator, about said common axis;
wherein the first and second Halbach arrays comprising the inner rotor and outer rotor, respectively, are further described as comprising permanent magnets fabricated by the steps of containing magnetic metal alloy powder in a non-magnetic tube, followed by swaging the magnetic metal alloy powder and non-magnetic tube.

### Claim 2 (depends on 1)

The dual-rotor machine of claim 1 wherein said stator comprises a double-helix winding configuration.

### Claim 3 (depends on 2)

The dual-rotor machine of claim 2 wherein said double helix magnet is further defined as a direct-double-helix winding configuration.

### Claim 4 (depends on 1)

The dual-rotor machine of claim 1 wherein said first Halbach array and said second Halbach array each produce a magnetic field that together form a resulting magnetic field characterized as having a flux density of up to 2.0 Tesla.

### Claim 5 (depends on 2)

The dual-rotor machine of claim 2 wherein said first Halbach array and said second Halbach array each produce a magnetic field that together form a resulting magnetic field characterized as having a field strength of up to 2.0 Tesla.

### Claim 6 (depends on 3)

The dual-rotor machine of claim 3 wherein said first Halbach array and said second Halbach array each produce a magnetic field that together form a resulting magnetic field characterized as having a field strength of up to 2.0 Tesla.

### Claim 7 (depends on 1)

The dual-rotor machine of claim 1 wherein the stored magnetic energy in the air gaps surrounding the stator for conversion to mechanical or electrical energy is at least 0.5 kJ/m.

### Claim 8 (depends on 2)

The dual-rotor machine of claim 2 wherein the stored magnetic energy in the air gaps surrounding the stator for conversion to mechanical or electrical energy is at least 0.5 kJ/m.

### Claim 9 (depends on 3)

The dual-rotor machine of claim 3 wherein the stored magnetic energy in the air gaps surrounding the stator for conversion to mechanical or electrical energy is at least 0.5 kJ/m.