ELECTRICAL MACHINE Russian patent published in 2001 - IPC

FIELD: electrical engineering; electrical machine cooling systems. SUBSTANCE: proposed ribbed-frame machine has external fan and shroud, as well as endshields provided with air admission holes; air exhaust holes are made in bottom part of frame between ribs in area free from stator stack. Mechanical design of electrical machine provides for unification of its frame with those of totally enclosed fan-cooled machines. High cooling efficiency of proposed machine is ensured due to large sectional area of cooling air admission and exhaust holes, easy access of cooling air to stator end windings and to butt end of stator stack, as well as due to great distance between holes admitting cold air and those exhausting hot air which actually eliminates effect of warm air suction inside electrical machine. EFFECT: improved cooling efficiency, reduced material input, enhanced reliability and service life of machine. 2 dwg