Drive system using a shape memory alloy wire

Abstract

A new drive system using shape memory alloy(SMA) wire is introduced in this paper. The system is designed for a car with the shape recovery force of SMA wire. A loop of SMA wire processed to memorize the straight line is set around a large pulley and a small one. When the wire around the small pulley is heated partially with hot vapor, it generates the recovery force at the heated part of the wire and turn to the torque to run the pulley. A bundle of wires can produce larger torque and it is possible to make SMA heat engine with the torque. In this study, the factors related to the rotational speed, such as diameter of small pulley, wire loop number and room temperature, were investigated. Moreover the relationship between wire loop number and torque too. It shows that the factors plays very important role. The speed of the unmanned car reached a few kilometers per hour.