Vibration Characteristics of Journal Bearing with Various Damping Materials

This paper presents an overview of the vibration problems which are experienced in running journal bearing. High vibration levels in machinery and components are usually undesirable as they often generate excessive noise and can lead to cyclic fatigue damage. The drive to reduce component mass, particularly in the aerospace and automotive industries, makes items more susceptible to vibration problems. In addition, many new high strength/high stiffness designs rely on ‘single piece’ welded metallic or fibrous composite constructions that have very little inherent damping. Damping materials have long been used to reduce vibration levels - examples vary from optimized constrained layer dampers on aircraft panels to bitumen spread on the underside of a metallic kitchen sink. Initially, most damping materials used were polymers with viscoelastic characteristics. In this work, a bearing testing apparatus is used for experimental studies to obtain displacement, velocity and acceleration from a journal bearing. Journal bearings are widely used to support the shaft of industrial machinery with heavy loads, such as compressors, turbines and centrifugal pumps. Vibration as a consequence of improper damping materials in journal bearing results in economic loss and creates high safety risks. So, it is necessary to reduce vibrations by selecting appropriate damping materials to the journal bearing and to achieve cost benefits to industry. Plywood, fibre, butadiene rubber and mud flap rubber was used to dampen the vibrations in the journal bearing. From the results, it is shown that the mud flap rubber possesses very good damping characteristics for journal bearing applications.