Thrust Analysis of a Reluctance-Based Magnetic Lead Screw with Flux-Concentrating Structure

Magnetic lead screws (MLSs) are lead screws that enable non-contact mechanical power transmission through magnetic force. We have proposed a simple-structured MLS constructed using arc-shaped permanent magnets magnetized radially. However, this structure reduces the opposing surfaces of the screw threads that generate magnetic attraction force, leading to decreased thrust and stiffness. Therefore, this paper presents a new MLS design with a magnetic flux-concentrating structure that allows the entire circumference of the opposing surfaces of the thread to be used for thrust generation. We calculate the thrust characteristics of the proposed MLS using a three-dimensional finite element method, reporting that it generates higher thrust compared to that of a conventional MLS with the same size.