# US 12,603,559 B2 · Variable cross-section conductors to reduce alternating current losses for axial flux, radial flux and motors with skew > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,603,559 B2 - Document ID: US12603559B2 - Status: Granted - Kind: B2 - Application number: 18/641,928 - Filed: 2024-04-22 - Published: 2025-10-23 - Granted: 2026-04-14 - Earliest claimed: 2024-04-17 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Vincent Fedida; Alan G. Holmes; Alexander Forsyth; Jian Yao - Web page: https://patentgrep.com/patent/US12603559B2 ## CPC - H02K 21/24: with magnets axially facing the armatures, e.g. hub-type cycle dynamos - H02K 1/16: Stator cores with slots for windings - H02K 3/28: Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A vehicle electric motor system includes an electric motor having a rotor. Multiple windings are mounted on the rotors individually having a coiled conductor including multiple conductor elements. A width of successive ones of the conductor elements is varied. At least one of the multiple conductor elements includes a continuous tapering body on the axis and alternatively at least one of the multiple conductor elements includes a smallest cross-sectional area having a first thickness approximately at a midpoint of the at least one of the multiple conductor elements and opposed ends positioned oppositely about the smallest cross-sectional area individually having a conductor element second thickness greater than the first thickness. ## Claims ### Claim 1 A vehicle electric motor system, comprising: an electric motor having: at least one rotor; and at least one stator; multiple permanent magnets positioned on the at least one stator; multiple windings mounted on the at least one rotor individually having a coiled conductor including multiple conductor elements, successive ones of the conductor elements varying in width, wherein the motor defines a radial flux motor, wherein the rotor includes an axial rotor skew, wherein the at least one rotor defines a first rotor and a second rotor, and the at least one stator defines a first stator and a second stator, wherein at least one of the multiple conductor elements positioned proximate to the first rotor and the second rotor and skews a load toward a d-axis of the radial flux motor has a cross-section change in an axial direction, wherein the at least one of the multiple conductor elements is shaped having a smaller cross-section compared to individual ones of the multiple conductor elements positioned proximate to a q-axis and skews the load toward the q-axis of the radial flux motor, wherein the at least one of the multiple conductor elements includes: a smallest cross-sectional area having a first thickness approximately at a midpoint of the at least one of the multiple conductor elements; and opposed ends positioned oppositely about the smallest cross-sectional area individually having a conductor element second thickness greater than the first thickness. ### Claim 2 (depends on 1) The vehicle electric motor system of claim 1, including a first airgap located between the first rotor and the first stator, and a second airgap located between the second rotor and the second stator, the first airgap and the second airgap together defining a dual airgap. ### Claim 3 (depends on 1) The vehicle electric motor system of claim 1, wherein the first rotor is axially skewed to a similar degree with respect to the second rotor, with the first stator positioned between the first rotor and the second rotor. ### Claim 4 (depends on 1) The vehicle electric motor system of claim 1, wherein conductor elements having a least width are positioned closest to a first airgap between the first rotor and the first stator and closest to a second airgap between the second rotor and the second stator. ### Claim 5 (depends on 1) The vehicle electric motor system of claim 1, wherein conductor elements having a greatest width are positioned closest to a center of a grouping of the multiple conductor elements. ### Claim 6 (depends on 1) The vehicle electric motor system of claim 1, wherein the cross-section change locally increases a slot-filling factor axially in the at least one of the multiple conductor elements. ### Claim 7 A vehicle electric motor system, comprising: an electric motor having: at least one rotor; and at least one stator; multiple permanent magnets positioned on the at least one stator; multiple windings mounted on the at least one rotor individually having a coiled conductor including multiple conductor elements, successive ones of the conductor elements varying in width, wherein the motor defines a radial flux motor, wherein the rotor includes an axial rotor skew, wherein the at least one rotor defines a first rotor and a second rotor, and the at least one stator defines a first stator and a second stator, wherein at least one of the multiple conductor elements positioned proximate to the first rotor and the second rotor and leaning toward a d-axis of the radial flux motor has a cross-section change on an axis of the electric motor, and wherein the at least one of the multiple conductor elements includes a continuous tapering body on the axis. ### Claim 8 (depends on 7) The vehicle electric motor system of claim 7, including a first airgap located between the first rotor and the first stator, and a second airgap located between the second rotor and the second stator, the first airgap and the second airgap together defining a dual airgap. ### Claim 9 (depends on 7) The vehicle electric motor system of claim 7, wherein the first rotor is axially skewed to a similar degree with respect to the second rotor, with the first stator positioned between the first rotor and the second rotor. ### Claim 10 (depends on 7) The vehicle electric motor system of claim 7, wherein conductor elements having a least width are positioned closest to a first airgap between the first rotor and the first stator and closest to a second airgap between the second rotor and the second stator. ### Claim 11 (depends on 7) The vehicle electric motor system of claim 7, wherein conductor elements having a greatest width are positioned closest to a center of a grouping of the multiple conductor elements. ### Claim 12 (depends on 7) The vehicle electric motor system of claim 7, wherein the cross-section change locally increases a slot-filling factor axially in the at least one of the multiple conductor elements. ### Claim 13 (depends on 7) The vehicle electric motor system of claim 7, wherein varying the width of individual ones of the multiple conductor elements balances alternating current and direct current loss effects. ### Claim 14 A method for reducing alternating current losses of a vehicle electric motor, comprising: producing an electric motor including mounting multiple windings on a first stator and an opposed second stator together defining a double stator; positioning the first stator and the second stator between a first rotor and a second rotor defining a double rotor; locating a first airgap between the first rotor and the first stator, and a second airgap between the second rotor and the second stator, the first airgap and the second airgap together defining a dual airgap; positioning multiple permanent magnets on the first stator and the second stator; mounting multiple windings on the first rotor and the second rotor; constructing individual coiled conductors for individual ones of the multiple windings having multiple conductor elements; and varying a width of individual ones of the multiple conductor elements. ### Claim 15 (depends on 14) The method of claim 14, further including configuring the electric motor as an axial flux motor wherein the first rotor and the second rotor have an axial skew. ### Claim 16 (depends on 14) The method of claim 14, further including configuring the electric motor as a radial flux motor wherein the first rotor and the second rotor have an axial skew. ### Claim 17 (depends on 14) The method of claim 14, further including positioning conductor elements having a least width closest to the first airgap and the second airgap. ### Claim 18 (depends on 14) The method of claim 14, further including positioning conductor elements having a greatest width closest to a center of a grouping of the multiple conductor elements. ### Claim 19 (depends on 16) The method of claim 16, further including shaping at least one of the multiple conductor elements positioned proximate to the first rotor and the second rotor and leaning toward a d-axis of the radial flux motor to have a cross-section change on an axis of the electric motor, wherein the at least one of the multiple conductor elements includes a continuous tapering body on the axis. ### Claim 20 (depends on 16) The method of claim 16, further including shaping at least one of the multiple conductor elements positioned proximate to the first rotor and the second rotor and skewing a load toward a d-axis of the radial flux motor to have a cross-section change in an axial direction, wherein the at least one of the multiple conductor elements includes a smallest cross-sectional area having a first thickness approximately at a midpoint of the at least one of the multiple conductor elements, and opposed ends positioned oppositely about the smallest cross-sectional area individually having a conductor element second thickness greater than the first thickness.