Magnetostrictive self-moving cell linear motor

The design and test of magnetostrictive linear motor that operates based on the self-moving cell concept is presented. The moving cell is composed of a magnetostrictive linear actuator and a ring structure, and a cell train is constructed by connecting two cells in series. Since this motor uses the stroke of Terfenol-D actuators and friction force of the cells, it can essentially produce long stroke and large push force. Essential part in designing such a magnetostrictive linear motor is the shape of moving cell. To achieve large clamping force and fast moving velocity, the cell structure is optimized invoking finite element analysis and Taguchi method. Also, since the displacement output of the actuator depends on the excitation frequency and current, the range of excitation current of the solenoid is determined by taking into account the time delay of the solenoid. Prior to test the overall performance of the motor, the performance of individual cell is tested in terms of the time delay, stroke, static friction force, and the minimum activation current. The overall performance of the motor is measured in terms of speed and force. In consequence, the maximum speed of 0.045 mm/s and the maximum stall force of 33 N are obtained. This work is a proof-of-concept stage and more investigation in terms of the increased number of cells, increased excitation frequency, wear and thermal effect are necessary. (C) 2003 Elsevier Science Ltd. All rights reserved.