Patent ID: 8847444

Claim:
A cooling system for a sealed permanent magnet electric machine comprising: a pumping element configured to urge an airflow across a plurality of permanent magnets of a rotor of the electric machine to remove thermal energy therefrom; a plurality of cooling channels disposed in a housing of the electric machine configured to transfer thermal energy from a stator of the electric machine to a flow of fluid coolant through the plurality of cooling channels; a coolant inlet disposed at an exterior wall of the electric machine to introduce the flow of fluid coolant into the plurality of cooling channels; a coolant outlet disposed at the exterior wall of the electric machine to direct the flow of coolant fluid out of the plurality of cooling channels such that thermal energy is dissipated from the flow of fluid coolant external to the electric machine; and a heat exchanger in thermal communication with the plurality of cooling channels and disposed radially outboard of the housing to transfer thermal energy from the airflow flowing therethrough to the fluid coolant, the heat exchanger including a plurality of radially stacked axially-directed heat exchanger channels to direct the airflow therethrough.