Design and Experimental Verification of a High Force Density Tubular Permanent Magnet Linear Motor for Aerospace Application

This paper presents the design and construction of a high force density tubular permanent-magnet (PM) linear motor. A strut structure of a tubular PM linear motor developed to improve resistance to impurities and structural rigidity is described. In the design, computationally efficient two-dimensional finite-element analysis is used to estimate the motor force density. The motor's design is optimized for the major pole number/slot number combinations of 8/24, 16/24, 20/24, 28/24, 32/24, and 40/24. The optimized motor design of a three-phase 16/24 combination with one-layer winding achieved the highest force-to-mass density. The force-to-mass density of the designed motor is higher than that of the first prototype motor by a factor of 5. The validity of the proposed design method and the expected drive characteristics are experimentally verified using the prototype. © 2019 SAE International. All Rights Reserved.