Analysis of flat voice coil motor for precision positioning system

The analysis of a flat voice coil motor (VCM) with Halbach array structure is described. The motor is applied for precision positioning system. Because of omitting boundary condition, the method of images is adopted to predict the distributions of global and local magnetic field for obtaining precise calculations. The derivation of flux density formulae are shown in this paper. By comparing flux density distributions, it proves that Halbach array structure could improve air-gap flux density. The method of images and FEA curves are coincident, at different position, demonstrates the analytically predicted distributions of air-gap flux density is exact.