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.

An annular axial flux motor includes a rotor mounted on an annular subsection of a rotatable cam ring and a stator mounted on an annular subsection of a carrier frame. The rotor includes two Halbach arrays of permanent magnets spaced from each other on the cam ring along an axial direction. The stator includes multiple phase electrical windings printed on multiple layers of a printed circuit board (PCB) that are stacked along the axial direction. The multiple layers are positioned between the Halbach arrays, with active side of the Halbach arrays facing to opposite sides of the multiple layers. The Halbach arrays are configured to generate a symmetrical magnetic field and the multiple phase electrical windings are configured to have a same rotor-dependent torque constant, such that the stator can generate a constant torque to rotate the rotor and the cam ring within a finite travel range.

An annular axial flux motor includes a rotor mounted on an annular subsection of a rotatable cam ring and a stator mounted on an annular subsection of a carrier frame. The rotor includes two Halbach arrays of permanent magnets spaced from each other on the cam ring along an axial direction. The stator includes multiple phase electrical windings printed on multiple layers of a printed circuit board (PCB) that are stacked along the axial direction. The multiple layers are positioned between the Halbach arrays, with active side of the Halbach arrays facing to opposite sides of the multiple layers. The Halbach arrays are configured to generate a symmetrical magnetic field and the multiple phase electrical windings are configured to have a same rotor-dependent torque constant, such that the stator can generate a constant torque to rotate the rotor and the cam ring within a finite travel range.

A magnet arrangement method in which magnetized magnets arranged in a Halbach array can be arranged at preset positions with a high accuracy is provided. The method includes an arrangement process of arranging a plurality of magnetized magnets in an arrangement jig made of a magnetic body, in which, in the arrangement process, a size of an area that the arrangement jig contacts a preset magnetized magnet is made different from a size of an area that the arrangement jig contacts another magnetized magnet.

A magnet arrangement method in which magnetized magnets arranged in a Halbach array can be arranged at preset positions with a high accuracy is provided. The method includes an arrangement process of arranging a plurality of magnetized magnets in an arrangement jig made of a magnetic body, in which, in the arrangement process, a size of an area that the arrangement jig contacts a preset magnetized magnet is made different from a size of an area that the arrangement jig contacts another magnetized magnet.

An electric motor including a coil assembly having a plurality of coils which may be arranged in the shape of a cylinder. The motor further includes a rotor including a plurality of outer magnets configured as a first Halbach cylinder surrounding the coil assembly. An outer magnet housing of the rotor is coupled to and surrounds the plurality of outer magnets. A plurality of inner magnets are arranged as a second Halbach cylinder with the coil assembly being interposed between the plurality of inner magnets and the plurality of outer magnets. An inner magnet housing is coupled to the plurality of inner magnets and surrounds an output shaft.

Rotors for electrical machines and methods of fabricating the same are disclosed. Electrical machine rotors may include a hollow non-magnetic shaft, an active region, and a plurality of coolant passages extending within the active region. The hollow non-magnetic shaft may extend along an axis and have an exterior surface that defines a shaft space extending along the axis. At least a portion of the active region may be disposed within the shaft space.

Modified magnetic levitation system for flying vehicle Modified magnetic levitation system for flying vehicle includes a propeller system (11, 12, 13), an axial levitation system (101, 102), radial levitation system (part of 201), rotary propulsion system (part of 201) and passive magnetic bearing system (301). An axial levitation system includes plurality of halbach array pairs connected on rotor and special short circuited coil windings connected on stator. A propulsion mechanism (part of 201) is provided for rotating rotor along the centre axis. Radial levitation and propulsion system (201) includes halbach arrays (53) located at outer circumference of rotor and interweaved active and passive coil windings (43) located at inner circumference of stator. Passive magnetic bearing system (301) includes parts of rotor and stator around centre axis of the system. Passive magnetic bearing (PMB) is utilized to levitate rotor at rest, below lift-off speed, and start and end condition of rotations.

Modified magnetic levitation system for flying vehicle Modified magnetic levitation system for flying vehicle includes a propeller system (11, 12, 13), an axial levitation system (101, 102), radial levitation system (part of 201), rotary propulsion system (part of 201) and passive magnetic bearing system (301). An axial levitation system includes plurality of halbach array pairs connected on rotor and special short circuited coil windings connected on stator. A propulsion mechanism (part of 201) is provided for rotating rotor along the centre axis. Radial levitation and propulsion system (201) includes halbach arrays (53) located at outer circumference of rotor and interweaved active and passive coil windings (43) located at inner circumference of stator. Passive magnetic bearing system (301) includes parts of rotor and stator around centre axis of the system. Passive magnetic bearing (PMB) is utilized to levitate rotor at rest, below lift-off speed, and start and end condition of rotations.

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.