Abstract: A rotor for an electric machine includes a rotor core having at least one internal cavity. A pair of features are defined by the rotor core and extend into the cavity. A structural element is compressed between the features so that a preload may be established between the features and the structural element.

Abstract: An axial flux motor includes: a stator having a first side and a second side opposite the first side, the stator including: N stator core components on the first side, where N is an integer greater than two; and pole shoes attached to radial sides of the N stator core components, N slot openings between adjacent ones of the pole shoes, where each of the N slot openings extends in at least one direction non-radially on the first side; and a rotor including a third side and M permanent magnets on the third side, where the first side is parallel to the third side, and where M is an integer greater than two.

Abstract: A rotary electric machine, e.g., a cycloidal reluctance motor, includes a stator having stator teeth connected to a cylindrical stator core, and a rotor having a cylindrical rotor core. The stator core and/or rotor core are constructed of grain-oriented, spirally-wound ferrous material having a circular or annular grain orientation. The stator teeth may be constructed of grain-oriented steel having a linear grain orientation. Notches may be spaced around an inner circumferential surface of the stator core, with each stator tooth engaged with a respective notch. The rotor may be eccentrically positioned radially within the stator. The rotor core may define notches spaced around its outer circumferential surface, with salient rotor projections engaged with a respective rotor notch. The machine in such an embodiment may be a switched reluctance rotor. An electrical system using the machine and a method of manufacturing the machine are also disclosed.

Abstract: Presented are electrical conductor assemblies with vascular cooling systems, methods for making/using such assemblies, and vehicles equipped with such assemblies for transmitting power and coolant between electric devices. An electrical conductor assembly includes an outer sheath, an electrical conductor extending through the sheath, a coolant channel defined through the sheath, and an optional cable jacket encasing the electrical conductor. The outer sheath has a tubular body formed from an electrically insulating material. The electrical conductor has a solid cable body located within a conductor duct extending through the sheath. The coolant channel, which is coaxial with and thermally connected to the cable body, passes therethrough coolant fluid that cools the electrical conductor. The cable jacket may be formed from an electrically insulating material having a thermal conductivity and melting point higher than that of the sheath.

Abstract: An axial flux-type rotary electric machine includes a rotor having a rotor axis and a stator having a stator axis. The stator is positioned adjacent to the rotor such that an axial airgap is defined between the rotor and the stator. First and second non-parallel rotor shafts are respectively collinear with the stator axis and the rotor axis. A nutating gear pair is connected to a stationary member and the rotor, and is configured to impart nutating motion to the rotor with respect to the stator, such that a size of the axial airgap changes with a rotational position of the rotor, and such that the rotor has two degrees of freedom of motion. An electrical system includes direct and alternating current voltage buses, a power inverter module connected to the voltage buses, and the axial flux-type rotary electric machine connected to the alternating current voltage bus.

Abstract: A modular drive system includes a first motor and a second motor. The first motor generates a first torque over a first torque bandwidth, and has a first stator, a first rotor, and a first winding. The first winding has a first number of turns, a first conductor area and a first insulation suitable for a first peak voltage of the first motor. The second motor generates the first torque over a second torque bandwidth, and has a second stator matching the first stator, a second rotor matching the first rotor and a second winding. The second winding has the first number of turns, the first conductor area and a second insulation suitable for a second peak voltage of the second motor. The second peak voltage is greater than the first peak voltage. The second torque bandwidth is wider than the first torque bandwidth.

Abstract: A method for constructing a rotor assembly for use with a rotary electric machine includes forming annular rotor laminations from metal blanks. Each lamination has a radial axis and an outer diameter surface. Multiple magnet web regions are defined in proximity to the outer diameter surface. Each web regions includes asymmetrical openings defined by a radially-extending strut and arcuate peripheral bridges. The method includes coaxially stacking the laminations into a rotor stack, including positioning every other lamination a predetermined angular distance with to unmask the bridges and/or struts and mask remaining surface area of the laminations. The rotor stack is subjected to a heat-treating process to harden only the unmasked bridges and/or struts. The method includes connecting a rotor shaft to the stack to construct the rotor assembly, with the web regions corresponding to a respective rotor magnetic pole.

Abstract: A method and system for controlling and regulating operation of a multi-phase rotary electric machine in a manner that minimizes power loss under partial load conditions is described. This includes an instruction set that is executable to determine a torque command and a rotational speed of the electric machine, determine a peak torque per loss parameter for the electric machine based upon the rotational speed, and determine a second torque parameter for the electric machine based upon the rotational speed. A modulated torque command for controlling the electric machine is determined based upon the peak torque per loss parameter and the second torque parameter, wherein the electric machine generates an average torque that is equivalent to the torque command when operating in response to the modulated torque command. The inverter is controlled to operate the electric machine based upon the modulated torque command.

Abstract: An apparatus for cooling an electric machine includes a plurality of fluid channels disposed in a first surface that surrounds at least part of the electric machine. Each of the plurality of fluid channels defines a circumferential path in the first surface, including a first channel section extending at least substantially parallel to first and second circumferences defined by ends of the electric machine, and including a second channel section configured to direct a cooling fluid between a central region of the first surface and an end region of the first surface. The apparatus also includes an outer shell configured to surround the first surface and define a fluid tight chamber between the first surface and the outer shell, the outer shell having at least one inlet through which the cooling fluid is introduced into the chamber and at least one outlet from which the cooling fluid exits the volume.

Abstract: A fluid-cooled axial flux motor having a stator, a rotor disposed adjacent to the stator, and a rotor shaft rotationally fixed onto the rotor. The rotor shaft includes axial coolant passageway having an inlet and opposite outlet. The rotor includes coolant passageways extending radially from rotor shaft. The rotor coolant passageways include an inlet in fluid communication with the outlet of the axial coolant passageway and an outlet. The fluid-cooled axial flux motor further includes a coolant distribution header having an inlet in fluid communication with the outlet of the rotor coolant passageway, a coolant collection header having an inlet in fluid communication with the outlet of the coolant distribution header, and a collection header outlet. The outlet of the coolant distribution header is disposed above the stator and the inlet of the coolant collection header is disposed below the stator with respect to the direction of gravity.

Abstract: A method and system for controlling and regulating operation of a multi-phase rotary electric machine in a manner that minimizes power loss under partial load conditions is described. This includes an instruction set that is executable to determine a torque command and a rotational speed of the electric machine, determine a peak torque per loss parameter for the electric machine based upon the rotational speed, and determine a second torque parameter for the electric machine based upon the rotational speed. A modulated torque command for controlling the electric machine is determined based upon the peak torque per loss parameter and the second torque parameter, wherein the electric machine generates an average torque that is equivalent to the torque command when operating in response to the modulated torque command. The inverter is controlled to operate the electric machine based upon the modulated torque command.

Abstract: A rotary electric machine includes a rotor assembly, stator, stator windings, and a coolant manifold. The rotor assembly includes a rotor and a rotor shaft. The stator is spaced apart from the rotor by a stator-rotor airgap and has stator teeth defining enclosed stator slots. Distal ends of adjacent stator teeth are joined together or integrally formed such that the enclosed stator slots are not contiguous with the airgap. The stator windings constructed from hairpin or bar-type conductors extend axially through the stator within the enclosed stator slots. The coolant manifold is in fluid communication with a coolant supply and configured to seal against an axial end surface of the stator to enclose a portion of the stator windings. The manifold receives and directs coolant from the coolant supply into the enclosed stator slots through the axial end surface to cool the stator via forced convection.

Abstract: A rotary electric machine for use with coolant includes a stator and rotor assembly. The rotor assembly includes a rotor, rotor shaft, and first and second end rings. The rotor has inner and outer diameter surfaces and an embedded set of rotor magnets proximate the outer diameter surface. The shaft is connected to the rotor and defines a main coolant passage along an axis of rotation. Radial shaft coolant passages are in fluid communication with the main coolant passage. The end rings are positioned at opposing distal ends of the rotor. The shaft coolant passages direct the coolant into the rotor and/or the end rings such that the coolant flows axially through rotor cavities of the rotor and cools the rotor magnets via forced convection.

Abstract: A stator assembly for an electric motor includes a laminate steel core arranged on an axis. The stator assembly also includes a fluid inlet and a fluid outlet. The stator assembly additionally includes a stator housing arranged on the axis concentrically with respect to the laminate steel core. The stator housing has a conduit fluidly connected to each of the fluid inlet and the fluid outlet and configured to circulate fluid around the laminate steel core. The stator assembly also includes a structural skeleton embedded in the stator housing. The structural skeleton is thereby configured to reinforce the stator housing. An electric motor employing the above-described stator assembly is also contemplated.

Abstract: A modular stator-inverter assembly for an electric machine includes a stator and a traction power inverter module (“TPIM”). The stator includes a stator core having a center axis, an inner diameter (“ID”), an outer diameter (“OD”), and electrical conductors forming stator windings. Stator teeth extending radially toward the center axis from the ID collectively define stator slots occupied by the stator windings. Each adjacent pair of stator teeth defines a respective stator slot. The TPIM delivers a polyphase voltage to the stator windings to generate a predetermined number of stator poles, such that the stator has either two, three, or four of the stator slots per electric phase per stator pole. The stator defines a center cavity and is configured to receive a selected rotor from an inventory of preconfigured machine rotors. The inventory includes multiple synchronous reluctance machine rotors and an induction machine rotor.

Abstract: A rotor for an electric machine includes a rotor core having at least one internal cavity. A pair of features are defined by the rotor core and extend into the cavity. A structural element is compressed between the features so that a preload may be established between the features and the structural element.

Abstract: An electric motor includes a stator, a rotor, a rotor shaft and a pump. The rotor is disposed within the stator and separated from the stator by an airgap. The airgap inadvertently accumulates a fluid. The rotor shaft is connected to the rotor. The pump is configured to move the fluid out of the airgap.

Abstract: An electric propulsion system includes a polyphase rotary electric machine that imparts motor torque to a load, a traction power inverter module (“TPIM”) connected to the electric machine, a reconfigurable energy storage system (“RESS”) connected to the TPIM, and a controller. The RESS has multiple battery modules and a switching circuit. The battery modules are connectable in a series-connected (“P-connected”) configuration at a first/low battery voltage level, and a series-connected (“S-connected”) configuration at a second/high battery voltage level that exceeds the first voltage. The controller determines power losses of the electric propulsion system at the first and second battery voltage levels, receives a commanded output torque and output speed of the electric machine, and selects the S-connected or P-connected configuration based on the predetermined power loss and commanded output torque and speed.

Abstract: Systems, methods and motor-generators with preform windings and a molded core are described. The preform windings include a first end, a second end, and a plurality of in-slot portions extending from the first end to the second end. The molded core includes a plurality of slots. Each of the plurality of slots including a respective in-slot portion disposed therein. Each of the plurality of slots includes a wall conforming to an outer profile of the respective in-slot portion.

Abstract: A vascular cooled capacitor assembly includes a plurality of capacitors having respective first and second leads, first and second busbars disposed in electrical contact with the first and second leads, an encapsulant enveloping the capacitors and a respective major portion of each of the first and second busbars, and a network of channels enveloped within the encapsulant and formed by deflagration of a sacrificial material. The network has at least one network inlet and at least one network outlet, each of which is configured for sealable engagement with a cooling fluid system. A branch of each channel is positioned inside a central axial passage of a capacitor, around an outer periphery of a capacitor, and/or between two capacitors. A housing may enclose the capacitors, the channels and major portions of the first and second busbars.