Rotor cage of single-phase induction motors - process analysis

Single-phase induction motor (SPIM) has been widely used in home appliances due to its simplicity, low cost, low noise and ruggedness. However, to produce a cost effective high efficiency SPIM is necessary to have a good knowledge and good control of process parameters. Dynamometer´s results of motors made with different process parameters show that rotor cages are more sensitive to process variations than stators and that they can to worsen the motor efficiency and torque characteristics. The aim of this work is to evaluate some steps of rotor cage process, namely rotor laminates coating, aluminum die-cast methods and rotor annealing and to analyze the effect of such parameters on motor performance. Results obtained from tests with a 2-pole, 100 W, high-efficiency SPIM are presented.