Development of an Actuator for Translatory Movement by Means of a Detented Switching Shaft Based on a Shape Memory Alloy Wire for Repeatable Mechanical Positioning

Actuators based on the shape memory effect have recently become more and economically important due to many advantages of alloys (SMAs), such as their high energy density. SMAs are usually used control end/maximum positions, thus actuators always move between two positions. The repeatable intermediate positions has so far proven difficult, because in most cases, external sensors necessary determine length SMA element. Additionally strategies for rather complex non-linear behavior this material. actuator presented here is able with accuracy without need a separate technology. integrated unit mechanical principle using shaft circumference groove. This groove height profile that turns shafts rotation, generated by SMA, into translational movement. Therefore, wire generates partial stroke at each complete activation, turning partially. With several activation cycles row, adds up until reaching maximum. A further cycle resets its initial position. Each part can, thereby, be controlled precisely repeatedly within scope actuator. Based an ratchet, can hold free.