Tosinal Vibrasion of Marine Propulsion Shafting System Containing Generator

The second macines (a generator and a pump, etc.) are often driven by a main engine in order to decrase energyloss in a marine propulsion shafting system. In case that a generator is driven, a sliding clutch controled by oil pressure is sometimes set btween a main engine and a generator for a fixed speed of a generator. But, a elastic couplings in two marine propulsion shafting systems containing this sliding clutch were damaged. Therefore, in order to clear up the causes of this accident, the characteristics of the torsional vibration of this marine propulsion shafting system was clarified by calculations. Furthermore, the experiments of the torsional vibration were made, using these shafting systems. According to the examination of the experimental and calculated results, it was clarified that this accidents happened by the torsional vibration which occured under the condition where a generator was driven. Next, in order to clear up the reason why this tosional vibration occured, the shafting systems in which the accident happened was compared with the shafting systems in which the accident did not happen, the stability of the shafting systems was examined by the vibration model in which the friction between the sliding clutch plates was considered, and the tosional vibrations were measured by using the testing machine containing the sliding clutch for the driving of a generator. Consequently, it was clarified that the accident happened by the self-excited vibration which occured in the sliding clutch.