Design, sensitivity analysis and fabrication of DC Linear Direct-Drive Motor (LDDM)

This paper presents a new analytical model for both magnetic flux density and thrust force in a DC tubular Linear Direct-Drive Motor (LDDM). Two-dimensional finite element method (FEM) is used for numerical analysis. Magnetic flux density and thrust force computed numerically shows a good agreement with the values resulted from proposed analytical model. This research, investigates the effect of some geometrical dimensions of LDDM. The sensitivity analysis of parameters highlights the influence of air gap, permanent magnet radius, coil´s length of phases and thickness of back-iron. It is found that lower air gap and thinner back-iron cause higher ratio of maximum thrust force to mover´s mass. Furthermore, the optimum value for coil´s length is also presented. The general shape of thrust force is also confirmed by experimental results.