THE STUDY OF A LINEAR MAGNETOSTRICTION MOTOR

Abstract

Magnetostrictive actuators are electrical machines that uses a magnetostrictive media which is being displaced by applying an external magnetic field. The bias magnetic field, necessary for displacing the magnetostriction core, can be ensured either by permanent magnets or by separate windings built for this purpose alone. In this paper a simplified, small dimension, linear magnetostrictive motor is analyzed by means of numerical simulation. The actuator has a driving winding, and a magnetization winding, respectively, which are coaxial disposed with the magnetostrictive material, here Terfenol – D. Both coils are powered by a pulse width modulated (PWM) voltage supply, and current supply, respectively, and the results of the numerical simulation are comparatively analysed. The prestress of the driving rod is not taken in consideration, as a result the rod does not return to its initial position, and the purpose of the simulation aims to establish the necessary level of prestress required by the mechanical spring. The friction between the contact pieces at the level of the intermediate piece is taken into account.