A radial flux rotary electric machine having an exterior-rotor configuration is shown. The machine has a permanent-magnet rotor comprising permanent magnets in a Halbach array, and an air-cored stator interior to the rotor having teeth defining tapered slots and distributed windings around the teeth to form coils in a double-layer arrangement, the windings being comprised of a plurality of phase windings. For each tooth T having a slot S1 on one side thereof and a slot S2 on another side thereof, a coil side C1 of a phase winding is arranged to occupy a radially inner layer of the slot S1 and a coil side C2 of the same phase winding is arranged to occupy a radially outer layer of the slot S2, wherein the coil side C1 has a smaller circumferential dimension and a larger radial dimension than the coil side C2.

A multi-stage spherical motor includes an inner stator, an outer stator, a rotor, and magnets. The inner stator has a plurality of inner stator windings wound thereon. The outer stator is spaced apart from and at least partially surrounds the inner stator, and has a plurality of outer stator windings wound thereon. The rotor is disposed between the inner stator and the outer stator and is configured to rotate about a plurality of perpendicular axes. The rotor has an inner surface and an outer surface. An inner array of magnets is coupled to the inner surface of the rotor, and an outer array of magnets coupled to the outer surface of the rotor. In some embodiments, a multi-stage spherical motor includes an inner rotor, an outer rotor, a stator, inner stator coils, and outer stator coils.

A rotary electric machine according to the present disclosure provides a rotary electric machine including: a rotor; and a concentrated winding stator arranged coaxially to the rotor, in which the number of teeth of the concentrated winding stator is set to be a value where an integer which is multiple of 3 between adjacent prime numbers in a prime number sequence is multiplied by 2 and the number of poles of the rotor is set to be a value where any prime number between the adjacent prime numbers is multiplied by 2.

A linear electromotive machine, for example a motor, generator and/or eddy-current brake is disclosed. The machine comprises a stator and a rotor, the rotor comprising a Halbach magnet array mounted on a fibre-reinforced polymer rotor frame. Also disclosed is a transportation system including such a machine and a method of manufacturing such a machine.

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.

The present disclosure relates to a motor, in particular a compact, lightweight and high torque motor. The rotor comprises a Halbach array magnet structure in which the projected magnetic field is directed toward the rotation axis of the motor and the stator comprises a plurality of poles within the Halbach array. The individual magnets making up the Halbach array have a thickness in the radial direction, with respect to the rotation axis, which is determined to be the minimum thickness required to stop demagnetisation of the magnets when the maximum current to generate peak torque output of the motor is driven through the stator at the maximum expected temperature at which the motor will be used.

One aspect of a rotor of the present invention includes: a rotor core rotatable about a central axis; and a rotor magnet fixed to an outer peripheral surface of the rotor core. The rotor magnet has a plurality of magnetized portions arranged along a circumferential direction in a Halbach array. The plurality of magnetized portions include a plurality of radially magnetized portions whose magnetization direction is a radial direction and a plurality of non-radially magnetized portions whose magnetization direction is different from the radial direction. The rotor core is a non-magnetic member that has a hole, recessed from a surface on one side in an axial direction of the rotor core to the other side in the axial direction and is made of a non-magnetic material. The hole is located on the radially inner side of the radially magnetized portion.

One aspect of a rotor of the present invention includes: a rotor core rotatable about a central axis; and a rotor magnet fixed to an outer peripheral surface of the rotor core. The rotor magnet has a plurality of magnetized portions arranged along a circumferential direction in a Halbach array. The plurality of magnetized portions include a plurality of radially magnetized portions whose magnetization direction is a radial direction and a plurality of non-radially magnetized portions whose magnetization direction is different from the radial direction. The rotor core is a non-magnetic member that has a hole, recessed from a surface on one side in an axial direction of the rotor core to the other side in the axial direction and is made of a non-magnetic material. The hole is located on the radially inner side of the radially magnetized portion.

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.