Electric machine with means for guiding cooling air supplied from outside of the machine

Electric machine having an exterior and an interior and provided with means for guiding cooling air from the exterior, said electric machine comprising a machine housing including two housing halves (17,18), each of said housing halves acting as an end shield, a lamination bundle (12) provided with a stator winding (13) having winding heads (13a, 13b), said lamination bundle (12) and said stator winding (13) being clamped in the machine housing between the housing halves, and a rotor (14) mounted in the machine housing to cooperate magnetically with the lamination bundle (12), wherein the machine housing is provided with at least one air guiding duct (33,34) circumferentially disposed about at least one of the winding heads (13a, 13b) of the stator winding (13) on one side of the lamination bundle and the at least one air guiding duct (33,34) is provided with at least one inlet opening (30) for admission of cooling air from the exterior and at least one outlet opening (40) for expulsion of the cooling air to carry away heat dissipated during operation, and each of the at least one air guiding ducts (33,34) is bounded exteriorly by one of the housing halves of the machine housing and interiorly by one of two annular walls (35,36) inserted between the lamination bundle (12) and the housing half bounding the at least one air guiding duct (33,34) exteriorly, and

• wherein an annular groove (37,38) is provided in an inside surface of each of the housing halves (17,18) to receive one of the annular walls (35,36) and said at least one winding head (13a, 13b) extends in said at least one air guiding duct so as to be exposed to the cooling air in said at least one air guiding duct.