Vibration reduction of propulsion shaft system by optimized bearing parameters

The vibrations of the propulsion shaft systems have a critical impact on the performance and noise control of underwater vehicles. Bearings are essential for the system’s dynamic performance as the support components. Existing studies have primarily focused on the impacts of the individual bearing parameters on system vibrations, while the effects of bearing designation, clearance, and tolerance, and bearing arrangement on the multi-bearing propulsion shaft system dynamics remain unclear. There is a lack of optimization design for multi-bearing parameters in propulsion shaft systems. A comprehensive dynamic model of the multi-bearing propulsion shaft system is developed in this study, which includes key components such as support bearings and the propeller. The effects of different bearings at different positions and bearing parameters on key vibration indicators (such as acceleration and displacement) are revealed through dynamic simulations. Based on the simulation results, a vibration optimization model for a multi-bearing propulsion shaft system is proposed, which can select effective bearing parameters. The optimal bearing parameters of the propulsion shaft system can be obtained through the optimization model. The findings not only provide quantitative criteria for low-vibration design of underwater propulsion systems, but also provide a theoretical reference for modeling and vibration control of complex multi-support rotating machinery.