A stator has a stator coil provided on an annular stator core. The stator coil is formed of electrical conductor wires each including an electrical conductor and an insulating coat. Each of the electrical conductor wires has a pair of exposed portions where the electrical conductor is exposed from the insulating coat and a covered portion where the electrical conductor is covered with the insulating coat. The pair of exposed portions are formed respectively at opposite end portions of the electrical conductor wire. The covered portion is formed at other portions of the electrical conductor wire than the end portions. At a coil end part of the stator coil, each corresponding pair of the exposed portions of the electrical conductor wires are welded together and each of the covered portions of the electrical conductor wires includes a coat-removed portion where the insulating coat is locally removed from the covered portion.

A motor includes a rotor molded by resin casting, and a stator disposed inside the rotor. The rotor includes a cylindrical portion in which a plurality of magnets are arranged side by side in a circumferential direction. The magnets are exposed on a side of an open end as one end of the cylindrical portion in an axial direction of the cylindrical portion. The cylindrical portion includes an inner resin located inside each of the magnets in a radial direction of the cylindrical portion. The inner resin includes a first resin portion, and a second resin portion closer to the open end than the first resin portion in the axial direction. A sectional area of the second resin portion perpendicular to the axial direction is smaller than a sectional area of the first resin portion perpendicular to the axial direction.

A motor rotor includes a rotatable shaft, and a magnet structure mounted around the shaft. The magnet structure includes magnet pieces including a first magnet piece and a second magnet piece. The first magnet piece has a fracture surface facing the second magnet piece, and an outer surface forming a circumferential surface of the magnet structure. A surface roughness of the fracture surface is greater than a surface roughness of the outer surface of the first magnet piece.

A motor rotor includes a rotatable shaft, and a magnet structure mounted around the shaft. The magnet structure includes magnet pieces including a first magnet piece and a second magnet piece. The first magnet piece has a fracture surface facing the second magnet piece, and an outer surface forming a circumferential surface of the magnet structure. A surface roughness of the fracture surface is greater than a surface roughness of the outer surface of the first magnet piece.

A stator core comprises a stack and a resin portion. The stack comprises an annular yoke portion, a plurality of tooth portions, and a plurality of slots. The resin portion covers an inner wall surface of a slot of the plurality of slots. The resin portion protrudes outward relative to an end surface of the stack in a height direction of the stack. The resin portion is formed on at least a part of an end surface of the tooth portion so as to extend from the inner wall surface of the slot around the end surface of the tooth portion. A resin end portion of the resin portion is disposed on the end surface of the stack and a corner of the resin end portion is formed as an inclined surface including a planar surface or curved surface.

A component, in particular a stator or a rotor, of an electric motor, in which a layer structure is generated is produced using additive manufacturing, by: forming, via alternate additive production, a layer assembly having first layers and second layers each first layer including a filament containing plastic and metal, and each second layer including a filament containing plastic and ceramic; heating the layer assembly a first temperature, at which the plastic is removed from the layers; further heating the layer assembly (2) to a second temperature, whereby the metal of the layer is sintered and an electrically insulating ceramic layer is obtained from the layer.

A component, in particular a stator or a rotor, of an electric motor, in which a layer structure is generated is produced using additive manufacturing, by: forming, via alternate additive production, a layer assembly having first layers and second layers each first layer including a filament containing plastic and metal, and each second layer including a filament containing plastic and ceramic; heating the layer assembly a first temperature, at which the plastic is removed from the layers; further heating the layer assembly (2) to a second temperature, whereby the metal of the layer is sintered and an electrically insulating ceramic layer is obtained from the layer.

A rotor for an electric machine includes a rotor body formed from a plurality of rotor laminations defining a first axial end and a second axial end. Each of the plurality of rotor laminations includes a plurality of openings that are aligned so as to define a plurality of passages through the rotor body. A plurality of reinforcement elements extend through the plurality of laminations. Each of the plurality of reinforcement elements is arranged in a corresponding one of the plurality of passages and includes a first end portion and a second end portion. The first end portion and the second end portion of select ones of the plurality of reinforcement elements extend outwardly of the first axial end and the second axial end. An end ring is positioned at the first axial end. The end ring is integrally formed with the select ones of the plurality of reinforcement elements.

A rotor for an electric machine includes a rotor body formed from a plurality of rotor laminations defining a first axial end and a second axial end. Each of the plurality of rotor laminations includes a plurality of openings that are aligned so as to define a plurality of passages through the rotor body. A plurality of reinforcement elements extend through the plurality of laminations. Each of the plurality of reinforcement elements is arranged in a corresponding one of the plurality of passages and includes a first end portion and a second end portion. The first end portion and the second end portion of select ones of the plurality of reinforcement elements extend outwardly of the first axial end and the second axial end. An end ring is positioned at the first axial end. The end ring is integrally formed with the select ones of the plurality of reinforcement elements.

An electric machine includes a plurality of printed layers arranged to form a stator having an outer periphery and teeth extending radially inward from the outer periphery. Each of the printed layers includes discrete portions of metal and discrete portions of insulation. The discrete portions of insulation define a contiguous network of insulative boundaries separating discrete cells formed by the discrete portions of the metal. A volume of the discrete cells within the outer periphery is greater than a volume of the discrete cells within the teeth such that a reluctance of the teeth is greater than a reluctance of the outer periphery.