Improving Endurance of Pneumatic Linear Peristaltic Actuators

Abstract

Pneumatic linear peristaltic actuators can offer some potential advantages when compared with conventional ones. Low cost, virtually unlimited stroke and easy implementation of curved motion profiles are among those benefits. On the downside, these actuators suffer high mechanical stress, which leads to short endurance and increased leakage between chambers during the actuator lifetime. This paper contributes to this field by experimentally characterizing the life behavior of a prototype of a linear pneumatic peristaltic actuator where force—instead of displacement—between rollers is imposed. It is shown that the use of an imposed force configuration has a significant impact in the actuator life time. In fact, the proposed actuator configuration has an average endurance of up to 250% higher than the one previously presented in the literature. This result was obtained while maintaining almost zero leakage between chambers, despite the hose wear throughout the service life. Finally, this paper explores the use of different hose geometries to increase the actuator life span. To this end, a preliminary study is presented where two different 3D printed hose cross sections are tested and compared with a circular one.