Analysis on toothless permanent magnet machine with Halbach array

Toothless permanent magnet (PM) machines with Halbach magnet array and normal one are studied comparatively in this paper. First of all, the analytic model is established for these two kinds of PM machines, then, their magnetic field distributions, magnitudes of magnetic flux at different locations are analyzed, laying emphasis on their different magnetic field variations along with the magnet thickness. These two kinds of PM machines without iron rotor are especially studied. One toothless stator, three kinds of rotor named as Halbach array iron one, Halbach array ironless one and normal array ironless one respectively are manufactured to structure three different prototyped machines, which have been used to verify the theoretical analysis successfully.