Translator eccentricity in permanent-magnet tubular machines is practically inevitable. It results in nonuniform air-gap magnetic-field distribution, which is inherently a 3-D problem. In this paper, the effects of eccentricity on field distribution and on the resulting unbalanced radial force are analyzed. Both no-load and load conditions are presented. The proposed mathematical model only requires the knowledge of the 2-D air-gap flux density distribution when the translator is at the balanced position. The analytical expression of the unbalanced radial force is derived together with the translator deformation analysis. The informa- tion of unbalanced radial forces acting on the translator and the translator displacement can be used for machine and bearing sizing. Analytically predicted and 3-D finite-element-calculated results are compared and validated by the experimental results obtained on a specially set-up test rig.
Analysis of Eccentricity in Permanent-Magnet Tubular Machines
MARIGNETTI, Fabrizio;
2014-01-01
Abstract
Translator eccentricity in permanent-magnet tubular machines is practically inevitable. It results in nonuniform air-gap magnetic-field distribution, which is inherently a 3-D problem. In this paper, the effects of eccentricity on field distribution and on the resulting unbalanced radial force are analyzed. Both no-load and load conditions are presented. The proposed mathematical model only requires the knowledge of the 2-D air-gap flux density distribution when the translator is at the balanced position. The analytical expression of the unbalanced radial force is derived together with the translator deformation analysis. The informa- tion of unbalanced radial forces acting on the translator and the translator displacement can be used for machine and bearing sizing. Analytically predicted and 3-D finite-element-calculated results are compared and validated by the experimental results obtained on a specially set-up test rig.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
