Abstract: A cooling jacket for an electric motor comprises a fluid passage disposed adjacent to a stator and configured to convey a cooling fluid. The cooling jacket includes a flow mixing enhancer within the fluid passage adjacent an axial end of the stator. The flow mixing enhancer includes baffles, a porous fibrous structure, and/or an open-cell foam to provide greater thermal conductance at a region adjacent to the axial ends than it provides to a central region therebetween. A flow bridge directs the cooling fluid through circumferential flow paths adjacent to both of the axial ends before the cooling fluid is circulated in a central flow path around the central region of the stator. One or more nozzles direct a jet of cooling fluid upon the stator end winding, a rotor end winding, and/or printed circuit board. A ring-shaped coolant header may supply the cooling fluid to the nozzles.

Abstract: An impingement cooling system includes a porous heat spreader and a nozzle configured to direct a fluid as a jet and/or as a spray impinging upon the porous heat spreader. The porous heat spreader is made of a thermally-conductive material such as a metal, metal alloy, carbon/graphite, or ceramic, and is in thermal contact with a heat source. The nozzle may be configured to direct the fluid as a jet comprising a single component liquid or gas (including air) or a liquid mixture such as water-glycol or other coolants. The nozzle may be configured to direct the fluid as a spray comprising a single component liquid or gas (including air) or a liquid mixture such as water-glycol or other coolants. The cooling system may include one or more nozzles, which may direct the cooling fluid orthogonally or at an oblique angle to an impingement plate.