Vibration Characteristics and its Countermeasure of Orifice Pipe for Reduction Gear Lubrication of Azimuth Thruster

아지무스 추진기의 감속 기어 윤활용 오리피스 파이프 진동특성과 방진대책

A type of electric propulsion employed by specialized purpose vessels or offshore is the azimuth thruster. Azimuth thruster application had been increasing recently and resulted to excellent vessel maneuverability. However, this system is very complex and some of its major component being exposed under the seawater level presents difficulty in sealing design. For Polar class icebreaker operating in extreme sea condition, this requires a high level of reliability and safety. In this study, the characteristics of lubricating orifice pipe structural vibration installed at the lower reduction gear were investigated and analyzed through beam analysis theory and comparison of experiments. Propeller excitation and the resonant modes of vibration causing excessive vibration and suitable countermeasures to prevent damage due to vibration fatigue on the pipe are presented.