Modern view on axial vibration of ship propulsion unit shafting

Authors: V.K. Rumb, Hoang Van Tu, A.V. Serov

Abstract

The article describes real cases where dangerous axial vibration of ship shafting occurred. The vibration occurrence mechanism is considered on the basis of the fluctuating deformation of the crank in the main engine crankshaft with the provision of the methodical background for its calculation and normalization. The differential equations for natural and forced axial oscillations are shown to be derived from similar equations for torsional ones. However, as opposed to the torsional vibration axial shafting vibration acts directly on the ship's hull through the thrust bearing. Shaft stresses occurring due to the axial vibration are shown to be too small to be used as an admissibility parameter, so it is preferable to control axial vibration by amplitude. The article also provides a summary analysis of the requirements of Classification Societies for axial shafting vibration.

Keywords: shafting, axial vibration, torsional vibration, damper, internal combustion engine

References

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2. Tanida K., Kubota M., Hasegawa N. Vibration Analysis of Crank Shaft for long Stroke Diesel using component Mode synthesis. Journal of the Kansai Society of Naval Architects. 1986, Japan, № 202, sep., pp. 107-118.

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5. Rumb V.K., Medvedev V.V, Ivanov M.Yu. Analiz trebovaniy inostrannykh klassifikatsionnykh obshchestv - chlenov MAKO к osevym kolebaniyam sudovykh valoprovodov [Analysis of Requirements of Foreign IACS Members for the Axial Vibrations of Ship Shafting]. Nauchno-tekhnicheskiy sbornik Rossiyskogo morskogo registra sudokhodstva [Research Bulletin by Russian Maritime Register of Shipping]. 2004, № 27, pp.150-159.

About authors

Rumb Viktor - PhD, professor, St. Petersburg State Marine Technical University, 3, Lotsmanskaya st., 190121, St. Petersburg, Russia

Hoang Van Tu - St. Petersburg State Marine Technical University, 3, Lotsmanskaya st., 190121, St. Petersburg, Russia

Serov Aleksey - PhD, FAI "Russian Maritime Register of Shipping", 8, Dvortsovaya naberezhnaya, 191186, St. Petersburg, Russia

Issue: 46/47 (2017)

For citation:  V.K. Rumb, Hoang Van Tu, A.V. Serov. Modern view on axial vibration of ship propulsion unit shafting. Research Bulletin by Russian Maritime Register of Shipping. 2017, No. 46/47, pp. 82-86.

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