Improvement of electric motor thrust by three-dimensional magnetic pole structure

In a linear motor which is used in various industrial applications, improvement of thrust density to minimize instrument size is desired. This paper presents a structure to increase the magnetic flux generated from a permanent magnet by three-dimensionally configuring magnetic poles. We constructed an analytical model of a cylindrical-type linear motor with the developed magnetic pole structure and compared the general SPM (Surface Permanent Magnet) structure with the permanent magnet quantity. As a result, the magnetic flux linkage of the developed model increased to about twice that of the comparison model. For this reason, it was confirmed by analyzing that the thrust increases to about twice that of the comparison model by increasing the air gap magnetic flux density without increasing the surface contributing to the generation of the force and the volume of the electric motor. © 2019 The Institute of Electrical Engineers of Japan.