Introduction

An actuator comprising a slide, a fixed frame, with respect to which the slide is suitable to move, and control means suitable to control said movement. Where the slide has a box shape with, inside, at least one pair of helical elements in a material selected from among the shape memory alloys.

Technical features

The device is composed by two couples of opposed SMA coil elements. The SMA elements are heated by means of Joule effect connecting their ends to an electric power supply through special terminal clips. The cooling is realized with an axial air fan. The movement of the slot is realized when both SMA elements of a couple are heated. The electric connection are realized to minimize the wirings connecting a couple of parallel SMA elements in electric series, in this way electric contacts are not needed on the slot, but only in the static part of the device. On the upper side of the static guide, there is the axial cooling fan, and the sliding slot is realized with openings on upper and lower sides to allow the air flow. The actuator exhibits a linear relation between the feeding electric current and the realized mean speed, independently by the applied mechanical load.

Possible Applications

• Opening-closing air vents in air plants;
• Thermal safety;
• Small domestic appliances;
• Automotive and aerospace sectors.

Advantages

• Compact;
• Silent;
• Can recycle thermal energy;
• Reduced overall dimensions.