Cooling of permanent magnet electric machine

摘要

A permanent magnet electric machine (10) includes a rotor (12) having a plurality of permanent magnets (16) and a stator (18) in magnetic communication with the rotor (12) and positioned defining a radial air gap (20) between the rotor (12) and the stator (18). A housing (26) is configured to seal the rotor (12) and the stator (18) from an outside environment. A pumping element (40) is configured to urge a closed loop airflow across the plurality of permanent magnets (16) to remove thermal energy therefrom, and a plurality of cooling channels (32) are located in the housing (26) and are configured to transfer thermal energy from the stator (18) to a flow of fluid coolant through the plurality of cooling channels (36). A heat exchanger (42) is located in thermal communication with the plurality of cooling channels (32) to transfer thermal energy from the airflow to the fluid coolant.