GB189861A - Improvements relating to armatures of direct-current electrical machines - Google Patents

Abstract

189,861. Fletcher, G. H., and Metropolitan-Vickers Electrical Co., Ltd. Sept. 5, 1921. Coils and conductors; cores. - An armature winding for use in stepped or tapered slots is formed of conductors or coils having different thicknesses on the two sides of a turn. Fig. 2 is a section of the conductor shown in Fig. 3, and the part 2 may be formed by re-rolling one-half of a conductor having the shape 3. For a tapered slot, a bar 3, Fig. 6, may be similarly treated. Alternatively, the two sides of a turn may be cut from a single bar, Figs. 7 and 8, the intermediate parts being removed from between the sides 2, 3, or two bars of the required shapes may be welded together as at 11. Connection to the commutator segments 9 is such that the thick conductors 3 in the upper parts of the slots fit into the wider parts of the commutator necks 8. In a modification, Fig. 9, where the conductors are grouped together into rectangular coils, the slot has such a shape that the coil side which fits into the upper part 6 of a slot is twisted through 90‹ relatively to the side in the lower parts 5 of another set. When the slot is half closed, the upper coil side may be divided into two parts to facilitate insertion.