GB262808A - Improvements relating to the ventilation of dynamo-electric machines - Google Patents

Abstract

262,808. Allgemeine Elektricitõts Ges. Dec. 10, 1925, [Convention date]. Armatures and field-magnets, cooling and ventilating.-Consists in au arrangement of ducts and separators for directing cooling air or other gaseous medium through the cores of dynamoelectric machines in which the medium enters the core radially from the outer circumference through inlet ducts between packets of the stampings, passes axially through passages and issues from the core radially through other outlet ducts between the stampings, the latter ducts preferably alternating with the former. Separating members are inserted between the packets of laminae such that pocket-like chambers are formed whereby cooling air which enters these pockets in the outlet slots from the air supply passages passes through the axial passages into the adjacent inlet slots, while in the inlet slots at the places where they cross the axial passages a part of the air issuing through the outlet slots passes outwardly after flowing through the corresponding axial cooling passages of the inlet slots. Fig. 1 shows a longitudinal section through a machine on the plane A, B, Fig. 4, and Figs. 3 and 4 respectively are sections on the planes EF, GH, Fig. 1. The medium passes from the end spaces 10 and passages 4 through inlet ducts 5, 5<1> between the packets and, owing to blocking rings 12 adjoining the air-gap, is deflected through axial passages 9 behind the winding slots to the inner parts of outlet ducts 6, 6<1>, whence it emerges from the machine at 11, as shown in Fig. 4. Separators 7 in the outlet ducts shut off a portion of these ducts so that their enclosed portions serve also to deflect some of the incoming medium axially through the passages 8 so as to join that in the inlet ducts 5, as shown in Fig. 1. Similar separators 7, Fig. 3, define pocket-shaped chambers at the outer parts of the inlet ducts such that a portion of the medium flowing radially outwards through the ducts 6, 6<1> from the axial passages 9 is deflected axially through the passages 8 into the enclosed upper parts of the inlet ducts 5 whence it emerges from the machine, as shown at 11, Fig. 3. Thus, each inter-packet duct is completely utilized, partly by incoming and partly by outgoing medium. The outlet ducts 6, 6' are open at the air-gap and the passages 9 may be merged into the winding slots without intervening iron. In place of air, nitrogen, hydrogen, carbonic acid gas or other medium may be used and it may be passed through the machine either by pressure or suction. In an alternative arrangement, the medium may pass along the air-gap instead of or in addition to the passages 9; also the pressure chambers 10 may be transposed to the centre of the machine in place of being at the ends. Specification 16391/13 is referred to.