Patent ID: 8183723

Claim:
A cooling jacket for a rotary electric device comprising: a jacket body having a first axial end, a second axial end and a mounting flange located adjacent the first axial end for coupling the jacket body with an outer housing, the jacket body further including a longitudinal center axis and having an inner cylindrical surface which defines a cavity centered about the longitudinal center axis, and an outer surface, the inner cylindrical surface extending from the first axial end to the second axial end and including an inner heat transference surface and the outer surface including an outer heat transference surface; the jacket body further including a set of circumferential annular grooves formed in the outer surface and each adapted to transition a cooling fluid in contact with the outer heat transference surface in a circumferential direction, and a set of axially advancing grooves formed in the outer surface and each adapted to transition the cooling fluid in an axially advancing direction between adjacent ones of the circumferential grooves, such that the cooling fluid follows a flow path which is circumferential of the cooling jacket a plurality of times when passed between an inlet and an outlet formed in an outer housing for the cooling jacket.