ELECTRIC MACHINE COOLING PASSAGE WITH INTERNAL FIN STRUCTURE

An electric machine is provided. The electric machine may include a shaft and a rotor. The shaft may define a rotational axis and a coolant passage that is transverse to the axis. The rotor may be assembled to the shaft and define an outer periphery, an inner periphery, and a medial section extending therebetween. The medial section may define a coolant channel that defines an inner edge and a plurality of elongated fins extending therefrom. The plurality of elongated fins may be configured to transfer heat from the outer periphery to coolant flowing from the coolant passage through the coolant aperture.