Analysis of magnetic pull effect in disk induction motor with symmetrical/asymmetrical air-gap

Abstract

Disk induction motor presents an interesting alternative to standard machine on account of its limited axial dimension. Its application may be contemplated for mine industry machines. However, in case of the design presented in this paper, a most significant drawback lies in magnetic pull axial forces appearing during normal operation of the machine and affecting bearing performance. This is why such forces should be considered at the design stage; this is particularly true, when design of magnetic circuit does not counterbalance those forces. The issue of magnetic pull occurring in disk induction motor with a single air-gap is presented in the paper for both symmetrical and asymmetrical air-gap. Results of calculations and measurements of axial forces under differing operating conditions of the motor are demonstrated. Particular attention is paid to analysis of axial force waveforms and their variations for different motor operating conditions.