Patent ID: 11955852
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 13:
14. A motor vehicle comprising:
a vehicle body;
a plurality of road wheels attached to the vehicle body; and
a traction motor attached to the vehicle body and operable to drive one or more of the road wheels to thereby propel the motor vehicle, the traction motor including:
a motor housing;
a direct-oil-cooling thermal management system fluidly connected to the motor housing and configured to circulate thereto a dielectric oil;
a stator assembly mounted inside the motor housing, the stator assembly including an annular stator core defining a hollow center and a plurality of circumferentially spaced stator slots, and a plurality of U-shaped electromagnetic hairpin windings each including a crown with legs projecting from the crown and extending through the stator slots such that exposed segments of the crown and the legs protrude from the stator slots; and
a rotor assembly rotatably disposed inside the hollow center of the annular stator core, the rotor assembly including a cylindrical rotor core defining a plurality of circumferentially spaced rotor slots, and a plurality of permanent magnets mounted inside the rotor slots in spaced relation to the hairpin windings,

wherein each of the hairpin windings of the stator assembly has a respective target surface with an oleophilic surface treatment configured to enlarge a wetted area of the target surface and increase a coolant mass of the dielectric oil contacting the target surface, the oleophilic surface treatment including a surface etching configured to exhibit an isotropic wetting behavior, the surface etching covering the exposed segments of the crown and the legs, only the exposed segments of the crown and the legs including the surface etching.