Design and Fault Analysis of Discrete Halbach Magnetic Screws

A magnetic screw is a device that utilizes the magnetic field of permanent magnets to convert between linear and rotational motions while achieving the gearing action simultaneously. This offers conversion between high-speed low-torque rotational motion to low-speed high-force translational motion and vice versa. The most tempting advantage that magnetic screws offer is the contact-free power transfer. This paper discusses the design of the discrete-Halbach magnetic screw since it offers higher thrust force due to its special arrangement of permanent magnets. Analysis for varying the number of segments of discrete-Halbach magnetic screw along with varying both the radial magnetized PM length and PM thickness is conducted using 3-D finite element analysis. Also, fault analysis including eccentricity and demagnetization is conducted.