Integration Design of MR Fluid Brake-Based External Rotor PMSM for Robotic Arm Applications

This article presents the integration design of magnetorheological (MR) fluid brake-based external rotor permanent magnet synchronous motor (PMSM) for robotic arm applications. By adding the inner braking teeth to the stator with outer armature teeth, the MR fluid (MRF) brake is integrated into the interior of the external rotor PMSM. The multimode stator design can allow the proposed machine to operate in both rotation and brake modes while improving space utilization in a relatively simple structure. First, the integrated machine topology and the operation principle in rotation and brake modes are illustrated. Then, this article focuses on the design of the core structure related to integrated topology, conducting analyses and optimization, and summarizing design considerations. Furthermore, the electromagnetic (EM) performances of the proposed machine are evaluated using a finite element (FE) analysis. The rated average EM torque is 2.09 Nm and the brake torque is 2.14 Nm. The simulation results validate the feasibility of proposed integrated topology.