Design and experimental analysis of a smart bearing using shape memory alloy springs

Abstract

Among many rotating machinery vibration sources, there is one due to resonance, when the machine operation frequency crosses the natural frequency region. This study proposes a smart bearing that employs shape memory alloy NiTi helical springs for vibration-level reduction. This smart bearing is capable of dynamically changing its stiffness during machine acceleration or deceleration, keeping its natural frequency far from resonance. Activated by Joule effect and cooled by forced air convection, the prototype installed in horizontal rotating machinery reaches reduction of vibration amplitude of about 63% (root mean square) and 73% (Peak) at critical speed, with response time between 12–15 s. Compared with the results of the reference articles, satisfactory amplitude reduction and better response time were observed.