The invention relates to an electric machine (1) comprising a stator (10) and a rotor (20) separated from the stator (10) by way of an air gap, wherein the rotor (20) has a plurality of shell-like magnet segments (30) secured to a rotor body (22), and wherein the magnet segments (30) have in the circumferential direction in each case a plurality of sections (32, 33, 34) with different magnetic polarizations, which each form a magnetic pole of the rotor (20), and wherein transition zones (36) are formed between the sections (32, 33, 34) of the magnet segments (30) with different magnetic polarizations, wherein recesses (40) are provided in the magnet segments on the side facing the stator (10). It is proposed that the transition zones (36) are formed so as to run obliquely in the axial direction of the rotor (20) and that the transition zones (36) are formed in the region of the recesses (40).

The invention relates to an electric machine (1) comprising a stator (10) and a rotor (20) separated from the stator (10) by way of an air gap, wherein the rotor (20) has a plurality of shell-like magnet segments (30) secured to a rotor body (22), and wherein the magnet segments (30) have in the circumferential direction in each case a plurality of sections (32, 33, 34) with different magnetic polarizations, which each form a magnetic pole of the rotor (20), and wherein transition zones (36) are formed between the sections (32, 33, 34) of the magnet segments (30) with different magnetic polarizations, wherein recesses (40) are provided in the magnet segments on the side facing the stator (10). It is proposed that the transition zones (36) are formed so as to run obliquely in the axial direction of the rotor (20) and that the transition zones (36) are formed in the region of the recesses (40).

A magnetic field coupling analysis and modulation method for a field-modulated permanent magnet motor based on a harmonic group is provided. The method includes: if a permanent magnet excitation source includes an outer surface-mounted permanent magnet and an intermediate permanent magnet and an armature magnetic source is an outer armature winding, acquiring a normal flux density component of an outer air-gap magnetic field of the motor; if the permanent magnet excitation source includes an inner surface-mounted permanent magnet and the intermediate permanent magnet and the armature magnetic source is an inner armature winding, acquiring a coupled flux density component of the outer air-gap magnetic field; calculating a coupling effect ratio, a harmonic characteristic factor, and a harmonic coupling efficiency in sequence from an air-gap flux density; determining positive and negative coupled harmonics according to the harmonic coupling efficiency; and establishing positive and negative coupled harmonic groups respectively.

A magnetic field coupling analysis and modulation method for a field-modulated permanent magnet motor based on a harmonic group is provided. The method includes: if a permanent magnet excitation source includes an outer surface-mounted permanent magnet and an intermediate permanent magnet and an armature magnetic source is an outer armature winding, acquiring a normal flux density component of an outer air-gap magnetic field of the motor; if the permanent magnet excitation source includes an inner surface-mounted permanent magnet and the intermediate permanent magnet and the armature magnetic source is an inner armature winding, acquiring a coupled flux density component of the outer air-gap magnetic field; calculating a coupling effect ratio, a harmonic characteristic factor, and a harmonic coupling efficiency in sequence from an air-gap flux density; determining positive and negative coupled harmonics according to the harmonic coupling efficiency; and establishing positive and negative coupled harmonic groups respectively.

A motor with a permanent magnet is provided. A motor has a rotor and an annular drive magnet surrounding the rotor. The drive magnet includes a plurality of magnetized areas having an entire circumference divided into a multiple of at equiangular intervals and includes a plurality of divided areas having an entire circumference divided into the same number as the number of magnetized areas at equiangular intervals. The two adjacent magnetized areas have different polarities. In an inner circumferential surface of each divided area in the drive magnet, a distance D from a rotation center line of the rotor becomes longer from a center in a circumferential direction toward both ends of the area. A magnetization polarization line of the two adjacent magnetized areas deviates from a boundary between the two adjacent divided areas in the circumferential direction.

A motor with a permanent magnet is provided. A motor has a rotor and an annular drive magnet surrounding the rotor. The drive magnet includes a plurality of magnetized areas having an entire circumference divided into a multiple of at equiangular intervals and includes a plurality of divided areas having an entire circumference divided into the same number as the number of magnetized areas at equiangular intervals. The two adjacent magnetized areas have different polarities. In an inner circumferential surface of each divided area in the drive magnet, a distance D from a rotation center line of the rotor becomes longer from a center in a circumferential direction toward both ends of the area. A magnetization polarization line of the two adjacent magnetized areas deviates from a boundary between the two adjacent divided areas in the circumferential direction.

Embodiments disclosed herein describe methods for improved permanent magnet motor rotor systems for submersible electric motors. The improved rotor system includes a single piece of material shaft with surface mounted permanent magnets. The single piece of material shaft minimizes the number of shaft bearings and locates the bearings outside of the stator windings.

A motor of an outer rotor type provided in an air blower includes a rotor rotatable about a central axis extending in a vertical direction, and a stator to drive the rotor. The rotor includes a magnet on which magnetized regions including magnetic poles different from each other are alternately arranged in a circumferential direction, and a rotor yoke which is provided on a radial-directional outer surface of the magnet using a magnetic material, and includes a yoke cylinder extending in an axial direction. A cross-sectional area of the yoke cylinder viewed in the circumferential direction at a circumferential-directional position that overlaps a space between the adjacent magnetized regions in the radial direction is larger than a cross-sectional area of the yoke cylinder viewed in the circumferential direction at a circumferential-directional position that overlaps an inner portion of each magnetized region in the radial direction.

A motor with a permanent magnet is provided. A motor has a rotor and an annular drive magnet surrounding the rotor. The drive magnet includes a plurality of magnetized areas having an entire circumference divided into a multiple of at equiangular intervals and includes a plurality of divided areas having an entire circumference divided into the same number as the number of magnetized areas at equiangular intervals. The two adjacent magnetized areas have different polarities. In an inner circumferential surface of each divided area in the drive magnet, a distance D from a rotation center line of the rotor becomes longer from a center in a circumferential direction toward both ends of the area. A magnetization polarization line of the two adjacent magnetized areas deviates from a boundary between the two adjacent divided areas in the circumferential direction.

A number of illustrative variations may include a rotor core for an electric motor comprising permanent magnets wherein the rotor core comprises lobes of the core material that magnets may be attached to.