GB396326A - Improvements in d. c. dynamo electric machines - Google Patents

Abstract

396,326. Windings for dynamo-electric machines. ENGLISH ELECTRIC CO., Ltd., 28, Kingsway, London, and WILSON, J. C., The Abbey, Great Haywood, Stafford. March 13, 1933, No. 7572. '[Class 35.] In a continuous-current dynamo-electric machine having two series connected armature windings with the commutators at opposite ends of the armature, a side of each coil shortcircuited by a positive brush on one commutator is adjacent to a side of a coil shortcircuited by a positive brush on the other commutator. The object of the invention is to ensure that the maximum voltage between the upper coil side of one winding and the lower coil side of the other winding never exceeds half the total voltage of the machine. In Figs. 3 and 4, two double layer windings are shown displaced longitudinally but in practice they would be superposed so that each slot contains four conductors, the top coil sides of each layer being shown in full lines and the bottom coil sides in dotted lines. According to the form shown in Fig. 3, the coils of the two windings progress in the same direction round the armature but they are of opposite hand, that is if the left-hand side of a coil of one winding is at a higher level than the right-hand side, reverse conditions obtain for the other winding. In the second form, Fig. 4, the windings are both of the same hand but progress in opposite directions round the armature. Fig. 2 shows a section through a slot containing the conductors O, N, B, C for the connection shown in Fig. 4. With the connection according to Fig. 3, coil sides O, N are interchanged.