US 11,955,852 B2
Oleophilic surface treatments for enhanced heat-transfer characteristics of electric machines
SeungHwan Keum, Northville, MI (US); Mei Yang, Troy, MI (US); Neal Parsons, Onsted, MI (US); and Ruth Herrera Reed, Warren, MI (US)
Assigned to GM Global Technology Operations LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Jul. 6, 2021, as Appl. No. 17/367,853.
Prior Publication US 2023/0011641 A1, Jan. 12, 2023
Int. Cl. H02K 15/12 (2006.01); H02K 3/12 (2006.01); H02K 3/44 (2006.01); H02K 9/19 (2006.01); H02K 15/02 (2006.01)
CPC H02K 15/12 (2013.01) [H02K 3/12 (2013.01); H02K 3/44 (2013.01); H02K 9/19 (2013.01); H02K 15/026 (2013.01); H02K 2209/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electric machine, comprising:
an outer housing;
a direct-cooling thermal management system fluidly connected to the outer housing and configured to circulate thereto a coolant fluid;
a stator assembly attached to the outer housing and including a stator core with an electromagnetic winding mounted to the stator core, the electromagnetic winding including a crown with a leg projecting from the crown and extending through a stator slot in the stator core such that exposed segments of the crown and the leg protrude from the stator slot; and
a rotor assembly movable with respect to the stator assembly and including a rotor core with a magnet mounted to the rotor core in spaced relation to the electromagnetic winding,
wherein the electromagnetic winding has a target surface with an oleophilic surface treatment configured to enlarge a wetted area of the target surface and increase a coolant mass of the coolant fluid contacting the target surface, the oleophilic surface treatment including a surface etching configured to exhibit an isotropic wetting behavior, the surface etching covering substantially all of the exposed segments of both the crown and the leg, only the exposed segments of the crown and the leg of the electromagnetic winding including the surface etching.