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 rotor assembly includes a rotor shaft and a rotor core supported by the rotor shaft and surrounded by a plurality of windings. The rotor assembly also includes a first brush engaging a first slip ring fixed relative to a first distal end of the rotor shaft. The first brush includes one of a first conical projection or a first convex receptacle and the first slip ring includes the other of the first conical projection or the first convex receptacle. A first electrical connection extends between the first slip ring and the plurality of windings. A second brush is configured to engage a second slip ring with the second slip ring fixed relative to the rotor shaft. A second electrical connection extending between the second slip ring and the plurality of windings.

Abstract: Synchronous electric machines including a stator having a plurality of conductive windings configured for carrying alternating currents for generating a rotating magnetic field (RMF), and a hybrid rotor configured for rotating within the stator according to a torque induced by the RMF. The hybrid rotor includes a plurality of laminations stacked together axially. The laminations include a non-permanent magnet subset of the laminations having one or more through-holes configured for limiting torque ripples. The laminations include a permanent magnet subset of the laminations having one or more pockets, with the pockets each removably holding one or more permanent magnets. The permanent magnets are operable for interacting magnetically with the RMF.

Abstract: Presented are electric machines with both bar and wire conductors, methods for making/using such machines, and vehicles equipped with such machines. An electric machine, such as a traction motor or electric generator, includes an outer housing, a stator fixedly mounted to the housing, and a rotor movably mounted to the housing and spaced across an airgap from the stator. Multiple magnets, such as permanent magnet blocks, are mounted on or in slots of the rotor (or the stator). A set of electromagnetic conductors extends through each radially elongated slot of the stator (or the rotor). Each conductor set includes a group of solid-wire or multistrand-wire conductors that is located adjacent the airgap. A group of hairpin or I-pin bar conductors is radially spaced from the airgap and located adjacent the wire conductors. The bar conductors have a cross-sectional area/shape that is distinct from a cross-sectional area/shape of the wire conductors.

Abstract: A propulsion system for a vehicle includes an electric motor configured to generate torque to propel the vehicle. The electric motor has a stator assembly with a plurality of stator slots defining slot layers along a respective slot axis. A first plurality of conductors is at least partially positioned in the plurality of stator slots and forming a first winding set. A second plurality of conductors is at least partially positioned in the plurality of stator slots and forms a second winding set. A first inverter is adapted to drive the electric motor, the first winding set being coupled to the first inverter. A second inverter is adapted to drive the electric motor, the second winding set being coupled to the second inverter. The system includes a controller adapted to control operation of the first and second inverters based in part on a motor speed of the electric motor.

Abstract: A slew rate controllable system for powering an electric machine. The system may include a plurality of power switches operable for converting a direct current (DC) input into an alternating current (AC) output suitable for electrically powering the electric machine. The system may include a gate drive system operable for controlling a slew rate associated with transitioning the switches between opened and closed states.

Abstract: Rotor flux control in a permanent magnet (PM) electric machine involves controlling fluid flow through the rotor based on the torque versus speed operating point of the PM machine. When the torque at a given speed falls below a predetermined threshold, the rotor receives a reduced fluid flow compared to when the torque is above the threshold. Fluid flow through the stator is controlled in an inverse manner relative to the rotor's fluid flow such that when the rotor experiences reduced fluid flow, the stator receives an increased fluid flow. This approach enables efficient control of the rotor's magnetic flux, enhancing the performance and efficiency of the PM electric machine during various operating conditions.

Abstract: An interior permanent magnet electric machine includes a stator and a rotor. The rotor features a rotor core with slots extending between its opposite ends. These slots contain a segmented magnet assembly, which includes magnet segments of different magnetic materials. The segmented magnet assembly may be divided radially, axially, circumferentially or combinations thereof and may include outer magnet segments made of the first magnetic material and inner magnet segments made of the second magnetic material. Additionally, the segmented magnet assembly includes magnetic poles that are aligned in radial, axial, or circumferential directions.

Abstract: An electric motor including a motor casing, a shaft having an axis of rotation, a first end and a second end, a first main bearing for rotatably supporting the shaft at the first end within the motor casing, a second main bearing for rotatably supporting the shaft at the second end within the motor casing, and a grounding bearing for conducting a bearing current between the shaft and the motor casing.

Abstract: An electric motor configuration includes a dual output multilevel inverter. The inverter includes a first and second set of alternating current (AC) phase outputs. The first set of AC phase outputs provide a current, each phase output of the first set of AC phase outputs corresponds to a phase output of the second set of AC phase outputs, and each phase output of the first set of AC phase outputs is offset from the corresponding phase output of the second set of phase outputs by 180 degrees. An electric motor includes a first and second set of antiparallel motor windings. The first set of motor windings is connected to the first set of AC phase outputs and the second set of motor windings are connected to the second set of AC phase outputs. The electric motor includes a mechanical rotation output.

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: An electric machine includes a housing, a rotor rotatably mounted to the housing, and a stator mounted to the housing about the rotor. The stator includes a stator body formed from a plurality of laminations. The plurality of laminations include an outer annular surface defining a radius, an inner annular surface spaced from the rotor, and a plurality of radially inwardly extending stator teeth spaced one from another by plurality of gaps. Each of the plurality of gaps extend along the radius and include an opening exposed at the inner annular surface. The opening has a first side portion and a second side portion each extending at an angle relative to the radius.

Abstract: A synchronous machine having a hybrid rotor excitation. The synchronous machine includes a rotor having a plurality of permanent magnets and electromagnets embedded within a rotor body. The permanent magnets produces a constant magnet field having a magnetic axis along a direct axis (D-axis). The electromagnets produces a variable magnetic field along a magnetic axis offset from the D-axis, preferable substantially orthogonal to the D-axis. The plurality of permanent magnets are separated from the electromagnets by a rotor air-gap. The plurality of permanent magnets includes inner pairs and outer pairs of permanent magnets nested in a V-shaped configuration. In another embodiment, the outer pairs of permanent magnets are replaced with outer radius electromagnets.

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: An electric machine includes a housing, a rotor rotatably mounted to the housing, and a stator mounted to the housing about the rotor. The stator includes a stator body formed from a plurality of laminations. The plurality of laminations include an outer annular surface defining a radius, an inner annular surface spaced from the rotor, and a plurality of radially inwardly extending stator teeth spaced one from another by plurality of gaps. Each of the plurality of gaps extend along the radius and include an opening exposed at the inner annular surface. The opening has a first side portion and a second side portion each extending at an angle relative to the radius.

Abstract: A rotary electric machine includes a rotor and a stator. The stator has windings and teeth extending radially from a stator core. Each tooth is separated from an adjacent tooth by a stator slot that opens to a radial stator-rotor airgap via a slot opening. The windings are positioned within each slot. Each stator tooth has a tooth tip with a surface profile configured to guide rotor flux away from areas of the windings proximate the respective slot opening. The tip surface profile may be a concave region, e.g., a dent/chamfer, and/or a convex region, e.g., a bump/bulge, and is formed in a distal end surface of the tip proximate the opening. The stator-rotor airgap is smaller at the convex region and larger at the concave region than elsewhere along the distal end surface. An electrical system includes the machine, a battery, and a power inverter module.

Abstract: A synchronous machine having a hybrid rotor excitation. The synchronous machine includes a rotor having a plurality of permanent magnets and electromagnets embedded within a rotor body. The permanent magnets produces a constant magnet field having a magnetic axis along a direct axis (D-axis). The electromagnets produces a variable magnetic field along a magnetic axis offset from the D-axis, preferable substantially orthogonal to the D-axis. The plurality of permanent magnets are separated from the electromagnets by a rotor air-gap. The plurality of permanent magnets includes inner pairs and outer pairs of permanent magnets nested in a V-shaped configuration. In another embodiment, the outer pairs of permanent magnets are replaced with outer radius electromagnets.

Abstract: A rotary electric machine includes a rotor and a stator. The stator has windings and teeth extending radially from a stator core. Each tooth is separated from an adjacent tooth by a stator slot that opens to a radial stator-rotor airgap via a slot opening. The windings are positioned within each slot. Each stator tooth has a tooth tip with a surface profile configured to guide rotor flux away from areas of the windings proximate the respective slot opening. The tip surface profile may be a concave region, e.g., a dent/chamfer, and/or a convex region, e.g., a bump/bulge, and is formed in a distal end surface of the tip proximate the opening. The stator-rotor airgap is smaller at the convex region and larger at the concave region than elsewhere along the distal end surface. An electrical system includes the machine, a battery, and a power inverter module.

Abstract: A rotating electric machine includes a stator and a rotor disposed within the stator. The stator defines a plurality of teeth and a plurality of semi-open slots. The plurality of semi-open slots further include a plurality of slot groups wherein each slot group further includes a plurality of slot subgroups. Each slot group includes at least a first subgroup of slots having a first slot opening width and being dedicated to a first phase, and a second subgroup of slots having a second slot opening width and being dedicated to a second phase, the second slot opening width being different from the first slot opening width.