Design and Preliminary Optimization of a Heat Exchanger Formed by Additive Manufacturing for Outer-Rotor PMSM

Permanent magnet synchronous motor (PMSM) with outer rotor has received extensive attention in direct drive applications. However, there is serious heat accumulation problem in the inner stator components under high torque density. In this study, an air-cooling heat exchanger (HE) is proposed to be installed inside the stator. Benefiting from the forming flexibility of additive manufacturing (AM) technology, the HE structure makes full use of the inner space and enlarges the convective area. Four key parameters of the HE structure are optimized through orthogonal test. Computational fluid dynamics (CFD) is mainly used to simulate the temperature rise of the motor system, and sample experiments have been designed to verify the accuracy of the CFD model and the feasibility of this cooling method.