Due to differences in the manufacturing process, centrifuged rotors have higher efficiency and interbar resistance than those produced by the high-pressure die-casting process. Therefore, the annealing applied to high-pressure die casted rotors to improve the insulation of the cage is not traditionally applied by manufacturers to centrifuged rotors. This study evaluates the effect of the traditional 450 °C heat treatment on centrifuged rotors, as well as the feasibility and effects of 520 oC rotor annealing, temperature not recommended for high-pressure die-casted rotors. The efficiency measurements were performed with a dynamometer, using small single-phase motors, usually applied in domestic refrigeration compressors, with a standard stator kept under controlled conditions. A structured test was performed to assess the effects in a mass production scenario, aiming to reflect the variation of the production parameters within the manufacturer specifications.
['Fabio Augusto Fujita', 'N. Sadowski', 'Patrick Kuo-Peng']
Use of Nontraditional Temperatures on Aluminum Caged Centrifuged Rotors Annealing—Assessment of the Viability and Effectiveness in Reducing Interbar Losses