Elimination of friction-induced vibration of a propulsion shafting system by auxiliary electromagnetic suspension

Abstract

This paper focuses on the problem of eliminating self-excited vibration in a propulsion shafting system induced by the friction of the water-lubricated rubber bearing. A new scenario involving electromagnetic suspension is proposed to change the condition of instability. To explore the mechanism of elimination of self-excited vibration, a dynamic model of the shafting system is established on the basis of Hamilton’s principle, the velocity-dependent friction model as well as the dynamics of the electromagnetic suspension. Influence of the electromagnetic force on the self-excited vibration of the system is evaluated. Transient responses of the system are obtained by using the Runge–Kutta fourth-order method. Numerical results indicate that the electromagnetic force can reduce the load on the rubber bearing and correspondingly the friction force on the interface. The occurrence of self-excited vibration will be delayed as the electromagnetic force increases, and once the suspension force increases to a critical value, instability of the system will be eliminated and vibration responses are damped exponentially.

Suppression of lateral vibration in a shafting system via an auxiliary active magnetic bearing with position control

“…But the active control of a rotor system is much centered on reducing the rotor vibration often caused by the unbalance whereas the active control of a shafting system is expected to suppress the vibration of the supports of the shaft. This paper studies the effectiveness of active magnetic bearing in lateral vibration suppression in a shafting system and it is a follow-up to the theoretic research conducted by Qin et al, 25 in which an active magnetic bearing is applied near the stern bearing and the ability of the active magnetic bearing to reduce the friction between the shaft and the stern bearing and eliminate the friction-induced vibration is theoretically proved. As a further study of the electromagnetic suspension, the dynamic model of a shafting system is formulated using the Timoshenko beam theory and Hamilton's principle and the performance of position control is analyzed.…”

An adaptive feedforward method in active vibration control for the propulsion shafting system

“…Active vibration control methods introduce a secondary control input adjusted by an active controller in real-time for eliminating the vibration responses of the propulsion shafting system. A range of strategies has been carried out in the last decades (Baz et al, 1990;Breńkacz et al, 2021;Caresta and Kessissoglou, 2012;Lewis and Allaire, 1987;Lewis et al, 1989aLewis et al, , 1989bPan et al, 2008aPan et al, , 2008bQin et al, 2019Qin et al, , 2020. Lewis and Allaire (1987) and Lewis et al (1989aLewis et al ( , 1989b employed an auxiliary magnetic bearing inserted in parallel with the thrust bearing of the shaft, providing a low dynamic stiffness on the longitudinal vibration isolations.…”

“…Active vibration control methods introduce a secondary control input adjusted by an active controller in real-time for eliminating the vibration responses of the propulsion shafting system. A range of strategies has been carried out in the last decades (Baz et al, 1990; Breńkacz et al, 2021; Caresta and Kessissoglou, 2012; Lewis and Allaire, 1987; Lewis et al, 1989a, 1989b; Pan et al, 2008a, 2008b; Qin et al, 2019, 2020). Lewis and Allaire (1987) and Lewis et al.…”

Experiments on vibration transmission control in a shaft-hull system excited by propeller forces via an activemulti-strut assembly

“…Caresta 23 used inertial actuators which are mounted at the prow to reduce the sound radiation of a submarine hull subjected to the lateral propeller forces. Qin et al 24,25 applied an auxiliary magnetic bearing to suppress lateral vibration transmission in a propulsion shafting system, and the numerical results show that the equivalent stiffness and damping of the support can be changed, resulting in reduced vibration and sound radiation of the hull. Zhu et al 26 proposed an AOS (Active Orthogonal Support) to suppress the lateral vibration transmission via the stern bearing in the shafting system.…”