Principle and test results of energy-saving effect of a single-drive bearingless motor in cooling fan applications

Abstract

This paper presents the energy-saving effect of a single-drive bearingless motor. In the single-drive bearingless motor, only the axial direction is actively positioned. The other radial and tilting directions are passively stabilized by repulsive passive magnetic bearings. Therefore, it has the advantages of low cost, absence of contact, maintenance-free and a long lifetime. In this paper, an additional advantage, an energy-saving effect, is verified. In experiments, the input power is measured with and without mechanical ball bearings. The bearingless motor can reduce the input power because the magnetic suspension power is low compared with the mechanical bearing loss. In addition, it is found that the efficiency can be improved.