Vibration diagnostic of rotor mechanisms in ships

Abstract

In ships, there are so many sources of noise and Vibration such as propulsion engines and electric generators in restricted spaces and structures of ships, which are made of steel, transmit vibration well. By the reasons, noise and vibration of ships are very big by nature and reduction of noise and vibration is important subject for ships. Regarding noise reduction, reduction of noise cause by vibration has difficulty and the major part of such noise is structure born noise. "Vibration" is not a problem. It is a physical manifestation of machinery imperfection. It is used to help find obvious and subtle deviations in machines. No machine runs perfect. "Diagnosis" is the Method of Detection. If, a fault develops and goes undetected, then, at best, the problem will not be too serious and can be remedied quickly and cheaply; at worst, it may result in expensive damage and down-time, injury, or even loss of life. There is no reason or excuse to have machinery operate unprotected. The areas of interest in vibration measuring in plant maintenance are general measurement, analysis, and corrective. All rotor mechanisms in ships consist of shafts, bearings, couplings, gears etc. These machinery operate under various load conditions from light to heavy. Ship propulsion system comparatively works under very heavy load conditions with rolling and pitching of the ship which may tend to cause overstressing of shafts.