A cooling system for an electrical motor or generator includes a first
cooling loop, a second cooling loop, and a heat exchange system. The
first cooling loop may extract heat from an iron stack and winding of the
electrical motor or generator. The second cooling loop may extract heat
from end turns of the stator winding, the rotor, and the bearings
independently from and simultaneously to the first cooling loop. At least
the first cooling loop may pass through the heat exchange system. A
liquid coolant may circulate in the first cooling loop and a compressed
gas, such as compressed air or compressed refrigerant in vapor form, may
circulate in the second cooling loop. The cooling system and method for
an electrical motor or generator may be suitable for, but not limited to,
applications in the aircraft and aerospace industries, such as driving a
cabin air compressor of an aircraft.