Patent ID: 7138735

Claim:
An internal ventilation system of a rotating electric machine having, within a housing, a fixed-mounted stator in the housing and a rotary-mounted rotor in the stator the ventilation system comprising: one ventilator integrated with the rotor which is capable of creating a cooling air stream within the housing, air intake axial orifices arranged in the housing, and cooling air discharge ports arranged in said housing in a ring with respect to the periphery of the ventilator and separated from each other by fins stiffening the housing in the area of the radial ports, wherein the angle of inclination of the fins in relation to the tangent perpendicular to the radial direction is between 38° and 52°, wherein the radial ports have an axial oriented section, called the axial orifice, that axially affects only the axial oriented ring and belongs to a cylindrical portion, and wherein the surface of the axial orifices represents at least 40% of the surface of the cylindrical section.