Analysis of the quality of squirrel cages rotor machined at Electroprecizia Electrical Motors

Abstract

The paper presents methods for improving the quality of rotor squirrel cages in the casting phase at Electroprecizia Electrical Motors Săcele. For this purpose, there are analysed the results of theoretical and experimental research on the existing interdependencies between the quality of rotor squirrel cages obtained by casting and the metallurgical quality of aluminium melts, respectively the parameters of the casting process. When balancing rotor squirrel cages, the non-homogeneity of the compactness of the cast aluminium mass raises a number of technological problems. This non-homogeneity of the compactness is determined by the presence of voids (bubbles, pores) in the cast material. However, the compactness of the aluminium mass (the voids in the cast aluminium) has a decisive influence on the electrical efficiency of the electric motor due to the drastic local modification of the electrical resistivity. Based on an analysis of the results obtained, there can be concluded that the development of a new family of electric motors, of super premium energy efficiency class (IE4), also involves the analysis and detection of the causes that lead to the formation of bubbles and pores in the cast aluminium mass, on the current process flow, subsequently reducing them by improving the existing technologies or even by replacing them.