Study On Theories Of Self-synchronization And Vibration Isolation For A Vibrating System With Octa-motor Drives

Synchronizaton phenomenon was discovered by Huygens, and self-synchronization theory was developed for hundreds of years and used in production. The machine with self-synchronization vibration was used widely because of its simple structure and easily fixing and maintaining. This kind of machines can transfer the vibration to surroundings, which causes uncomfort ableness for workers, machines around it working unhealthy and even accindents as a result of its vibration. However, the common design for vibration isolation can reduce the influence of it on surroundings, but it cannot eliminate the vibration stemming from the vibrating machine. Therefore it is necessary to devise a new method for reducing the influence further.The synchronization theory for an octa-motor vibrating system with two-stage vibration isolation was investigated in this paper. The main work is as follows.(1) Firstly, the mechanical model of this system was established. Kinetic energy, potential energy and functions of energy dissipation for the system were expressed. Then applying them to Lagrange's equation, the equations of motion for the system are obtained.(2) Self-synchronization of eight coupled exciters in the vibrating system was developed by electromechanicalcoupling theory. The frequency capture equations for the eight exciters were deduced by modal analysis, so the complicated problem of multi-exciter synchronization was converted into one of existence and stability of zero solutions for the frequency capture equations. By combining the existence of the frequency capture equations with the general dynamic symmetry for two coupled exciters in the vibrating system, the conditions of implementing system for three groups of different combined phase differences were obtained. The criterion of synchronization stability was proposed by using the generalized Lyapunov equation, Lyapunov criterion and Routh-Hurwitz criterion.(3) Computer simulations were carried out to verify the above theoretical results. The rotational speeds of the motors, phase differences among the octal exciters, the displacements of each vibrating machine and two-stage vibration isolation frame were given out to verify the theoretical results. The effect of the damping and spring stiffness on the stability of self-synchronization for octal exciters was investigated by computer simulation.