Rotor for induction motor

802,385. Squirrel cage constructions. GENERAL ELECTRIC CO. June 20, 1956 [June 20, 1955], No. 19106/56. Class 35. Each slot 2 of each lamination of the laminated squirrel cage rotor core of an A.C. induction motor comprises a first main portion 3 which when aligned with respective portions 3 of all the other laminations accommodates a cast substantially straight bar 7 of the winding, and a second portion extending from the first portion substantially radially inwards of the core, the medium plane of each of the second slot portions 4, 4a of one and of the other of two groups of stacked laminations 1, 1a being parallel to but displaced laterally to one side and to the other side respectively of the medium plane of the respective slot first portion 3 so that in one of the two groups a winding bar extension 9 cast in its slot second portion 4 is interrupted by the laminations 1a of the other group whose second portion 4a is displaced in the opposite direction. As shown, one group comprises a stack of several laminations 1 separated from the next stack of that group by a single lamination 1a of the other group, and the latter lamination is a punching of shape identical to that of the first group laminations but is reversed with respect to the latter. End rings 8, and fan blades 10 at one or both ends of the rotor, are integrally cast with the rotor winding 7 which preferably is of aluminium. The slots may be skewed and aligned by a keyway 6 in the rotor bore 5.