Design of axial eddy current couplers

This paper presents different analytical and numerical approaches devoted to the analysis and design of axial eddy current couplers. The main part of the work regards a pure analytical procedure based on variable separation method (VSM). This methodology requires a preliminary linearisation of the structure to reduce the three-dimensional (3D) problem to a two-dimensional (2D) one. The 2D analytical model is compared with 2D finite element (FE) analysis and the comparison shows the reliability of the proposed model. The analytical procedure is then largely employed for a detailed parametric study to give useful information to the designer of eddy current couplers. A double-sided stator with permanent magnets and single and multi-layers conductive disk rotors is considered. In order to take into account 3D effects, two different models are proposed. In the first one the VSM is coupled to a 2D FE model; in a second model a closed analytical formula allows to consider 3D effects. All the models are validated with experimental results and with 3D FE analysis.