Optimal Design of a Tubular Hybrid Stepping Motor Under Volumetric Constraints

A design procedure for tubular hybrid stepping motors realized using soft magnetic composite materials and laminations is presented in this paper. The design is aimed to maximize the thrust of the motor for given volumetric constraints, taking into account the thermal limits and the maximum flux density in the magnetic circuit. The proposed method is based on the combined use of Finite Element Method (FEM) and equivalent reluctance network approach. The design procedure has been applied to a typical motor geometry, showing the influence of the most important geometrical parameters, which are the slider diameter, the number of teeth per pole and the inner diameter of the permanent magnet.