Analysis and Experimental Verification of Radial-Gap Two-Degree-of-Freedom Motor Based on a Magnetic Screw Structure

This article proposes a radial-gap two-degree-of-freedom motor based on a magnetic screw structure. The proposed motor is composed of stator parts, rotor parts, and a mover part, and can generate torque and thrust force simultaneously and independently. Additionally, the motor can generate a large thrust force with the magnetic screw structure. In the proposed motor, the rotor parts and mover part, which act as the nut and screw of ball screws, are coupled with each other by means of magnetic force. Therefore, there is no friction between the rotor parts and mover part. The proposed motor can not only contribute to the minimization of multidegree-of-freedom systems, such as industrial robots but also improve the energy efficiency of robots. This article examines the effectiveness of the proposed motor through analysis and experimental results.