GB190916811A - Improvements in and relating to Alternating Current Electric Induction Motors. - Google Patents

Abstract

16,811. Siemens Bros. Dynamo Works, and Kieffer, E. O. July 19. Armatures.-The squirrel-cage bars and endrings of an induction motor are cast into position on the core of the rotor so that the whole winding forms one continuous piece of metal without joints. The end-rings may be cast with fan vanes or projections, and those parts of the bars projecting from the slots may be thinned and radially lengthened so as to act as fan vanes. The end plates g, Fig. 3, of the rotor may be shaped so as to serve as a mould within which the end-rings d may be cast, asbestos or other fibrous material k being interposed so as to allow for inward shrinkage of the ring d &c. In order to prevent molten metal from entering the radial ventilating-ducts p, Fig. 4, the plates at each side of the ducts are made thicker, and special distance-pieces of metal strip bent so as to form a loop of the same size as-the rotor slots are mounted on one of the plates. The loops come opposite the slots and form passages for the molten metal. Alternatively, the plates at each side of the ducts may be made with slots rather larger than the core slots, and ferrules or metal tubes f are inserted therein so as to bridge the ducts.