Synchronization of Four Axisymmetrically Distributed Eccentric Rotors in a Vibration System

Abstract

This paper studies synchronization of a class of even pairs and symmetrically distributed eccentric rotors in a vibration system of a single mass body. A vibration system driven by four ERs with circular distribution structure and the same rotating direction is adopted as the dynamic model. The motion differential equations of the system are established based on Lagrange equation. The angular velocity and the phase of each rotor are perturbed by the average value of the synchronous velocity. The state equation of the system is obtained by applying the averaging method. According to the necessary condition of the steady-state motion, the synchronization condition and the dimensionless coupling torques of the system are deduced. The stability condition of the synchronous motion is derived by applying Lyapunov indirect method. The distribution law of the steady-state phase difference is discussed qualitatively by the numerical analysis of the theoretical results. Then combined with the numerical results, five sets of experiments are carried out on the experimental machine, which includes the sub-resonant state and the super-resonant state. The experimental results show that this vibration system has two super-resonant motion states and one sub-resonant motion state. The experiment proves the correctness of the theory, which can provide theoretical guidance for the design of this kind of vibration machine.

Analyses of synchronous motion characteristics for a two-rigid-body vibration system with three co-rotating eccentric rotors mounted on two different rigid bodies

“…Moreover, the changes in phase differences will significantly affect the amplitudes of vibrating bodies. Chen and Liu (2020, 2022) conducted studies on single rigid body vibration systems driven by three or four eccentric rotors. He found that the rotational speed has a significant effect on the stable phase differences before and after the resonant region, and the system can perform two kinds of steady state motions with different phase differences in super-resonant state.…”