LIQUID-COOLED ROTARY ELECTRIC MACHINE HAVING FLUID CHANNEL WITH AUXILIARY COOLANT GROOVE

A liquid-cooled rotary electric machine including a heat transfer surface traversed by a fluid channel defining a flow path for liquid coolant through the machine. A first fluid channel portion extends about and progresses in a direction parallel to the central axis, and is interconnected with a second fluid channel portion at spaced locations along the first fluid channel portion. The heat transfer surface includes a zone which the first fluid channel portion does not traverse, and is located between a jacket axial end and the first fluid channel portion. The second fluid channel portion extends into the zone between the interconnections, whereby the zone is traversed by the second fluid channel portion and heat is convectively transferable from the zone to liquid coolant along the flow path. Also, a method for liquid-cooling a rotary electric machine.