Effect of machine defects on its radiated noise

Abstract

Great concern is directed towards noise reduction in industrial workplaces for the sake of workers. Many studies have been performed to discuss the methods of active and passive noise control. One of the principles that can be applied is: Healthier Machines Result in Quieter Environment. The importance of well maintained, rigid, balanced, aligned, damped, and effectively isolated machinery cannot be neglected when discussing the reduction of radiated noise. Vibration of machinery should be kept to a minimum as it is radiated into the room as noise, either directly from the machine by panels, worn bearings and moving parts, or via the supports and building structure as structure born noise. This work aims to clarify the importance of this fact. The effect of machine faults on produced noise is investigated. Machine faults include errors in design, manufacture or assembly, as well as wear or failure of different machine elements. The results showed good coherence between the vibration produced by the machine and the radiated noise. Moreover, it was proven that the noise of a machine can be dramatically reduced by keeping its elements in a good condition and the working parameters according to the design specifications. Applying fault diagnosis techniques to the machine, an overall noise reduction of about 15 - 20 dB was achieved. It is also accompanied by better performance.