전기 모터 구동 대빙급 추진 시스템의 과도 비틀림 진동 분석

Abstract

A ship’s propulsion shafting system is subjected to varying magnitudes of intermittent loadings that pose great risks such as failure. Consequently, the dynamic characteristic of a propulsion shafting system must be designed to withstand the resonance that occurs during operation. This resonance results from hydrodynamic interaction between the propeller and fluid. For ice-class vessels, this interaction takes place between the propeller and ice. Producing load- and resonance-induced stresses, the propeller-ice interaction is the primary source of excitation, making it a major focus in the design requirements of propulsion shafting systems. This paper examines the transient torsional vibration response of the propulsion shafting system of an ice-class research vessel. The propulsion train is composed of an electric motor, flexible coupling, spherical gears, and a propeller configuration. In this paper, the theoretical analysis of transient torsional vibration and propeller?ice interaction loading is first discussed, followed by an explanation of the actual transient torsional vibration measurements. Measurement data for the analysis were compared with an applied estimation factor for the propulsion shafting design torque limit, and they were evaluated using an existing international standard. Addressing the transient torsional vibration of a propulsion shafting system with an electric motor, this paper also illustrates the influence of flexible coupling stiffness design on resulting resonance. Lastly, the paper concludes with a proposal to further study the existence of negative torque on a gear train and its overall effect on propulsion shafting systems.