Abstract: A rotor assembly for an electric machine includes first laminates, second laminates; and a rotor shaft, wherein the first laminates and the second laminates are arranged in a stack on the rotor shaft. Each of the first laminates includes a first inner portion and a plurality of first outer portions, wherein the first inner portion and the first outer portions define a plurality of first cavities, wherein the plurality of first outer portions are secured to the first inner portions via a plurality of bridges. Each of the second laminates includes a second inner portion and a plurality of second outer portions. The second inner portion and the plurality of second outer portions define a plurality of second cavities, wherein the second outer portions are secured to the second inner portions via a plurality of second webs and are absent a bridge.

Abstract: A rotor shaft system for a vehicle includes a rotor shaft having a first shaft end opposite a second shaft end. The rotor shaft has a first segment and a second segment defined between the first shaft end and the second shaft end. The rotor shaft system includes a shaft gear coupled to the rotor shaft between the first shaft end and the first segment, and a shaft sleeve coupled to the first segment so as to surround a portion of the shaft gear. The rotor shaft system includes a lubrication system defined at least partially through the rotor shaft and the shaft sleeve. The lubrication system is to supply a fluid to at least a portion of the rotor shaft and the shaft sleeve.

Abstract: A rotor for an electric machine includes an air circulation cooling system. The rotor includes a rotor core having cavities internal to the rotor core. The rotor core extends longitudinally between two ends. The cavities are defined by the rotor core. The cavities extend through the rotor core and open through at least one of the ends. The rotor core operates to circulate air through the cavities by rotation of the rotor core.

Abstract: A rotor for an electric machine including a rotor core having a plurality of circumferentially spaced rotor poles. Each rotor pole may include a plurality of rotor slots arranged into one or more magnetic layers and one or more non-magnetic layers. The magnetic layers may include a magnet within one or more of the rotor slots thereof and the non-magnetic layers including no magnets within the rotor slots thereof.

Abstract: A method of incorporating additive domains in a rare earth magnet, a system for incorporating additive domains in a rare earth magnet, and a traction motor including a rare earth magnet. Inert gas and a plurality of coarse neodymium-iron-boron (NdFeB) particles are introduced into the chamber of a jet mill. The plurality of coarse NdFeB particles impact each other producing a plurality of refined NdFeB particles. The plurality of refined NdFeB particles also impact a target including a target material and transfer a portion of the target material onto a surface of the refined NdFeB particles. The plurality of refined NdFeB particles including the target material are separated from the plurality of coarse NdFeB particles and collected to form a rare earth magnet.

Abstract: A hairpin conductor includes two wire segments each having respective first and second ends and a respective middle region. The segments are disposed in a side-by-side orientation such that their first ends are proximate each other and their second ends are proximate each other. The first ends are welded to each other and the second ends are welded to each other, or the middle regions are welded to each other, thereby providing a welded wire assembly, which is bent such that the two wire segments are bent equally to form the hairpin conductor. The hairpin conductor has a primary bend in the middle regions to form an apex thereat and first and second secondary bends in the two wire segments nearer to the apex than to the first and second ends to form respective first and second shoulders thereat. A method of forming the hairpin conductor is also presented.

Abstract: A motor stator includes a plurality of stacked annular stator laminates defining a stator core having an inner circumference, an outer circumference, a plurality of stator teeth on the inner circumference, and a plurality of ears extending outward from the outer circumference with a respective bolt hole defined in each ear. A first set of the stator laminates includes a plurality of coolant openings therethrough, wherein the coolant openings of adjacent stator laminates communicate with one another in order to define cooling channels inside the stator core. A second set of the stator laminates each include one or more generally radially extending first openings therethrough, wherein the first openings of adjacent stator laminates communicate with one another to define one or more first radial channel segments inside the stator core for providing radial coolant flow between one or more bolt holes and one or more cooling channels.

Abstract: Presented are direct liquid cooling systems for regulating magnet temperature of electric machines, methods for making/using such systems, and motor vehicles equipped with traction motors having magnets cooled by such systems. An electric machine includes a stator assembly that is located inside a protective outer housing. The stator assembly includes one or more electromagnetic windings mounted onto a stator core. A rotor assembly is rotatably attached to the housing, coaxial with and spaced from the stator assembly. The rotor assembly includes one or more permanent magnets mounted to a rotor core. The rotor core includes one or more radially elongated feed grooves that are fluidly connected to one or more axially elongated feed channels. The rotor feed groove(s) fluidly connect to a direct liquid cooling system to receive therefrom a liquid coolant. Each rotor feed channel transports the liquid coolant into direct contact with a target surface of a magnet.

Abstract: An exposed terminal for a wire conductor, and a process for preparing the exposed terminal includes executing, via a mechanical device, a mechanical ablation process to remove the insulative material from an outer surface of the plurality of square edges along a predefined length of the portion of the wire conductor. The process also includes executing, via a laser tool, a laser ablation process to remove the insulative material from the first pair of opposed faces along the predefined length of the portion of the wire conductor; and executing, via the laser tool, the laser ablation process to remove the insulative material from the second pair of opposed faces along the predefined length of the portion of the wire conductor.

Abstract: Presented are electric machines with optimized stator tooth geometries and multi-gauge stator conductors, methods for making/using such electric machines, and motor vehicles equipped with such electric machines. An electric machine includes a housing, a rotor assembly rotatably attached to the housing, and a stator assembly coaxial with and separated by an airgap from the rotor assembly. The rotor assembly includes one or more magnets mounted to a rotor core. The stator assembly includes a stator core with multiple axially elongated, circumferentially spaced stator slots, multiple radially aligned stator teeth interleaved between and separating the slots, and multiple electromagnetic windings wound through the slots. Each stator tooth has an elongated tooth body with a tooth head at a radial end of a tooth root, which attaches to a cylindrical hub of the stator core. The tooth head has an axial cross-section with a trapezoidal crown integral with a rectangular tip.

Abstract: A hairpin conductor includes two wire segments each having respective first and second ends and a respective middle region. The segments are disposed in a side-by-side orientation such that their first ends are proximate each other and their second ends are proximate each other. The first ends are welded to each other and the second ends are welded to each other, or the middle regions are welded to each other, thereby providing a welded wire assembly, which is bent such that the two wire segments are bent equally to form the hairpin conductor. The hairpin conductor has a primary bend in the middle regions to form an apex thereat and first and second secondary bends in the two wire segments nearer to the apex than to the first and second ends to form respective first and second shoulders thereat. A method of forming the hairpin conductor is also presented.

Abstract: A motor stator includes a plurality of stacked annular stator laminates defining a stator core having an inner circumference, an outer circumference, a plurality of stator teeth on the inner circumference, and a plurality of ears extending outward from the outer circumference with a respective bolt hole defined in each ear. A first set of the stator laminates includes a plurality of coolant openings therethrough, wherein the coolant openings of adjacent stator laminates communicate with one another in order to define cooling channels inside the stator core. A second set of the stator laminates each include one or more generally radially extending first openings therethrough, wherein the first openings of adjacent stator laminates communicate with one another to define one or more first radial channel segments inside the stator core for providing radial coolant flow between one or more bolt holes and one or more cooling channels.

Abstract: Presented are electric machines with optimized stator tooth geometries and multi-gauge stator conductors, methods for making/using such electric machines, and motor vehicles equipped with such electric machines. An electric machine includes a housing, a rotor assembly rotatably attached to the housing, and a stator assembly coaxial with and separated by an airgap from the rotor assembly. The rotor assembly includes one or more magnets mounted to a rotor core. The stator assembly includes a stator core with multiple axially elongated, circumferentially spaced stator slots, multiple radially aligned stator teeth interleaved between and separating the slots, and multiple electromagnetic windings wound through the slots. Each stator tooth has an elongated tooth body with a tooth head at a radial end of a tooth root, which attaches to a cylindrical hub of the stator core. The tooth head has an axial cross-section with a trapezoidal crown integral with a rectangular tip.

Abstract: A rotor core for an electric machine of an automobile includes a core stack including a plurality of lamination plates, each lamination plate including a plurality of apertures formed therein, the apertures of each of the lamination plates axially aligned to define a plurality of magnet slots extending axially through the core stack, a plurality of magnets stacked axially within each of the plurality of magnet slots along a length of the core stack, at least one of the plurality of magnet slots including a cavity extending axially along the length of the core stack, and a wedge inserted within the cavity adapted to apply a lateral force onto the plurality of magnets within the at least one magnet slot to secure the plurality of magnets within the at least one magnet slot.

Abstract: An electric machine may include a substantially annular stator stack having a plurality of laminations which include mounting ears. A fraction of the laminations may be oriented such that the mounting ears are angularly offset from the others. The stator may be secured to a housing at both mounting ear locations thus improving structural rigidity and enhancing performance.

Abstract: A rotor core for an electric machine of an automobile includes a core stack including a plurality of lamination plates, each lamination plate including a plurality of apertures formed therein, the apertures of each of the lamination plates axially aligned to define a plurality of magnet slots extending axially through the core stack, a plurality of magnets stacked axially within each of the plurality of magnet slots along a length of the core stack, at least one of the plurality of magnet slots including a cavity extending axially along the length of the core stack, and a wedge inserted within the cavity adapted to apply a lateral force onto the plurality of magnets within the at least one magnet slot to secure the plurality of magnets within the at least one magnet slot.

Abstract: An electric machine includes a machine rotor circumscribed by a machine stator, and having a rotor shaft, rotor stack, and end cap which rotate about an axis. The end cap includes lobes equal in number to a number of pole pairs of the machine rotor. A position sensor assembly has a predetermined alignment with the machine rotor and stator. The sensor assembly includes a sensor rotor formed by the lobes and a sensor stator having a printed circuit board with conductive sine and cosine traces. Machine rotor rotation causes the sensor assembly to output an unmodulated sine and cosine signals to a controller, which then calculates a calibrated reference angle. A magnetic axis of an electrical phase of the machine is aligned with and bisects a peak of the sine trace. A direct axis of the machine rotor aligns with an edge of a lobe.

Abstract: An electric machine may include a substantially annular stator stack having a plurality of laminations which include mounting ears. A fraction of the laminations may be oriented such that the mounting ears are angularly offset from the others. The stator may be secured to a housing at both mounting ear locations thus improving structural rigidity and enhancing performance.

Abstract: An electric machine includes a machine rotor circumscribed by a machine stator, and having a rotor shaft, rotor stack, and end cap which rotate about an axis. The end cap includes lobes equal in number to a number of pole pairs of the machine rotor. A position sensor assembly has a predetermined alignment with the machine rotor and stator. The sensor assembly includes a sensor rotor formed by the lobes and a sensor stator having a printed circuit board with conductive sine and cosine traces. Machine rotor rotation causes the sensor assembly to output an unmodulated sine and cosine signals to a controller, which then calculates a calibrated reference angle. A magnetic axis of an electrical phase of the machine is aligned with and bisects a peak of the sine trace. A direct axis of the machine rotor aligns with an edge of a lobe.

Abstract: A stator assembly includes a plurality of stator slots having multiple respective slot layers and a plurality of hairpins. The plurality of hairpins have a respective first leg positioned in one of the multiple respective slot layers and a respective second leg positioned in another of the multiple respective slot layers. A first set of n adjacent slots of the plurality of stator slots is configured to accommodate the plurality of hairpins carrying a current in a first phase, n being an integer. The plurality of hairpins is configured in respective conductor layers (L1, L2 . . . ) having a plurality of respective turn locations defining n respective turn positions. The plurality of hairpins is configured to occupy the n respective turn positions an equal number of times such that the respective conductor layers (L1, L2 . . . ) are electrically balanced.