Dynamic analysis of a propulsion shaft system considering the flexible coupling and motor isolations

This paper presents a dynamic model for the propulsion shaft system of an unmanned underwater vehicle. The model considers the effects of the flexible coupling and motor isolators. The motor bearings, shaft support bearings, thrust bearing and propeller are considered. A multi-degree of freedom isolation model for the motor stator is established. The coupling effects of shaft, motor bearings, shaft support bearings and motor excitation are considered. A finite element mode analysis and forced vibration experiment is conducted to provide the verification. The influences of the shaft speed, flexible coupling stiffness, motor isolation stiffness and installation position on the system vibrations are studied by using the numerical model. This study could provide some guidance for the dynamic analysis and vibration optimization of the propulsion shaft systems of UUVs.