Improvements in rotors for squirrel-cage alternating current electric motors

摘要

214,536. Waygood-Otis, Ltd., (Otis Elevator Co.). Aug. 28, 1923. Alternating-current inductionmachines; conductors. - In squirrel-cage motors operated at different speeds by variation of the number of active poles upon the stator, the end rings of the rotor are provided with spaced slots 4 that extend at intervals partly around the ring and determine the resistance of the path between consecutive rotor bars according to the number of poles in operation. For a two-speed motor a single ring of slots 4 is provided, and for a three-speed motor an additional ring of slots 7 is provided. Alternate end rings are arranged so that their slots are relatively staggered. Radial slots 2 may also be provided extending nearly to the line of slots 4.