Experimental Validation of Collision Safety in Prismatic Joints Using Magnetic Coupling

Abstract

This study presents a prismatic joint structure that utilizes magnetic coupling to enhance safety during collisions. Conventional prismatic joints using electric motors typically involve components such as gearboxes and rigid couplings. In contrast, the proposed design features permanent magnets arranged on the motor output shaft and the gearbox input shaft, enabling non-contact power transfer through an axial magnetic coupling mechanism. The proposed design prevents overload by utilizing the decoupling of the magnetic coupling in the event of a collision. This results in improved safety of mechanical components during impact situations compared to conventional designs. Prior to experimentation, magnetic film was employed to verify the magnet arrangement, and the transmitted torque via the distance between magnet array was experimentally determined. The experiment compared the motor speed, q-axis current, and the load applied to the impact surface during the collision process, based on the presence or absence of magnetic coupling. Experimental findings confirmed the proposed effect provided by the magnetic coupling. © 2025 IEEE.