Radial-Force-Based Swirling Actuator with Surface-Permanent-Magnet Structure for Low-Speed High-Torque Applications

This paper proposes a swirling actuator that utilizes the electromagnetic radial force and a swirling gear to generate rotational torque. This actuator converts the swirling motion to the rotational motion and is suitable for low-speed high-torque applications. The air-gap flux density and the radial force generation are investigated analytically. The 3D FEA results of the net radial force between the stator and the SPM-structure swirler are presented to evaluate the theoretical results. It is shown that the proposed actuator is possible to realize a maximum torque density of 58 Nm/L for a short time, which is notable in small volume machines.