Design of a Decoupled Double-Stator Flux-Switching Permanent-Magnet Rotary-Linear Motor with Two Degree-of-Freedom Motion

This paper proposes a new double-stator flux-switching permanent-magnet rotary-linear (FSPM-RL) motor, in which both linear and rotary motions can be achieved individually and simultaneously. The proposed motor contains two decoupled structures for achieving two degree-of-freedom motions separately by adopting two sets of orthogonally arrayed PMs. Firstly, the topology and flux path for each motion are introduced. Then, the operating principle and analytical equations related to the performance of each motion are presented. Afterwards, the effect of leading parameters on end-effect and force/torque performance are investigated based on 2D finite-element method (FEM). Moreover, the simulation results of optimized design under 2D FEM are verified by 3D FEM. Meanwhile, by using 3D FEM, the performances under helical motion are investigated. Besides, the performances under helical motion are compared with that under the condition of only linear or rotary motion separately. It is indicated that the output force/torque under the helical motion are nearly the same to that with only linear or rotary motion. In such way, the proposed motor shows good ability in decoupling the rotary and linear motion, which is the common issue in RL motors.