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.

A motor includes a stator and a rotor, the rotor includes a frame coupled to a rotation shaft and a magnet fixed to the frame, with a direction from the stator toward the rotor as a first direction, the magnet includes a plurality of lower part main pole magnets having a magnetization direction in the first direction and pluralities of lower part second rightward sub-magnets and lower part second leftward sub-magnets having a magnetization direction in a direction different from the first direction, the lower part main pole magnet includes a lower part first upward main magnet placed at a negative side in the first direction and a lower part second upward main magnet fixed to the frame, when the magnet is seen along the first direction, the lower part first upward main magnet and the lower part second rightward sub-magnet and lower part second leftward sub-magnet partially overlap.

A field magnet holder provided at a field portion of an electric motor is formed of a non-magnetic material. An inner wall and outer wall of the field magnet holder are respectively formed in annular shapes. Plural spacers are arranged between the inner wall and outer wall at a predetermined spacing in the circumferential direction. Sockets into which permanent magnets are inserted are formed between the spacers of the field magnet holder, plurally in the circumferential direction. Therefore, the permanent magnets may be easily assembled by being respectively inserted into the sockets. The plural permanent magnets are arrayed with magnetization directions thereof successively changed in steps of an angle that is a full cycle of electrical angles divided by a division number n, which division number n is any one integer that is at least three. Thus, ease of assembly of the permanent magnets is improved.

Electric machine having: a shaft; a rotor with permanent magnets that is fitted to the shaft; a stator having a magnetic core which consists of a series of laminations made of ferromagnetic material and longitudinally crossed by a plurality of stator slots; and a stator winding having a plurality of rigid bars that are inserted in corresponding stator slots and that are covered, on the outside, with an insulating coating. Each stator slot is completely free from an insulating element interposed between the ferromagnetic material making up the laminations of the magnetic core and the corresponding bars, so that an outer surface of the corresponding bars is in direct contact with an inner surface of the stator slot made of the ferromagnetic material.

The invention relates to a non-cogging electric generator having at least one stator and at least one dual rotor, wherein the dual rotor comprises a plurality of primary magnet devices arranged in circular Halbach array. Non-cogging is achieved by having inner and outer rotor rotating synchronously. Concentration of magnetic flux is achieved by magnetic devices tapering into pyramidal shape, such that magnetic devices arranged on the inner rotor are facing magnetic devices on the outer rotor, whereas said magnetic devices are facing each other with the opposite polarity. Stator comprises electrical wire windings and is positioned between inner and outer rotor.

The invention relates to a non-cogging electric generator having at least one stator and at least one dual rotor, wherein the dual rotor comprises a plurality of primary magnet devices arranged in circular Halbach array. Non-cogging is achieved by having inner and outer rotor rotating synchronously. Concentration of magnetic flux is achieved by magnetic devices tapering into pyramidal shape, such that magnetic devices arranged on the inner rotor are facing magnetic devices on the outer rotor, whereas said magnetic devices are facing each other with the opposite polarity. Stator comprises electrical wire windings and is positioned between inner and outer rotor.

A permanent magnet brushless motor, robot joint, a servo actuator, and a robot are provided. The motor is of fractional-slot and inrunner type, including a stator (1) and a rotor (2). The stator (1) includes a stator iron core (10) and a stator winding, the stator winding is a concentrated winding, and the stator iron core (10) has an integral structure. The stator iron core includes a stator yoke and stator teeth, the stator teeth include a plurality of stator teeth (102) protruding from the stator yoke, and the surfaces of the stator teeth (102) are provided with insulating layers. The stator winding comprises a plurality of preset winding coils (11) formed by machine, and each stator tooth is inserted into x winding coils, wherein x is greater than or equal to 1.

A permanent magnet brushless motor, robot joint, a servo actuator, and a robot are provided. The motor is of fractional-slot and inrunner type, including a stator (1) and a rotor (2). The stator (1) includes a stator iron core (10) and a stator winding, the stator winding is a concentrated winding, and the stator iron core (10) has an integral structure. The stator iron core includes a stator yoke and stator teeth, the stator teeth include a plurality of stator teeth (102) protruding from the stator yoke, and the surfaces of the stator teeth (102) are provided with insulating layers. The stator winding comprises a plurality of preset winding coils (11) formed by machine, and each stator tooth is inserted into x winding coils, wherein x is greater than or equal to 1.

A motor for an electrical submersible pump includes a stator and rotor, where the rotor is made up of adjacent columns of magnets affixed onto an annular core. End rings on opposite ends of the core provide axial backstops for magnet columns. Thin coaxial sleeves are shrunk fit over the magnets and end rings and that radially compress the magnets. Apertures in a column are formed radially through the core and receive fasteners for securing a guide bar to the core. The guide bar simulates an installed column of magnets to guide placement of adjacent columns of magnets as the guide bar width is substantially the same as a column of magnets, and aperture locations are strategically positioned so that when the guide bar is secured onto the core. After the guide bar is removed the one of the columns of magnets is then adhered to the core.

An electric motor is provided and includes inner and outer rotors, a stator supportive of back iron radially interposed between the inner and outer rotors and a winding structure. The winding structure includes first phase coils radially interposed between the inner rotor and a first side of the back iron, the first phase coils extending axially along the first side of the back iron, second phase coils radially interposed between a second side of the back iron and the outer rotor, the second phase coils extending axially along the second side of the back iron and end windings respectively extending radially between corresponding ones of the first and second phase coils.