Avaliação de fontes de perturbações síncronas e assíncronas na obtenção das respostas em frequência de sistemas dinâmicos rotativos.

Abstract

In this work has been presented a study on the effects of the residual unbalance of flexible rotors in the dynamic behavior of rotating machines. One of the most important problems and discussed by the Mechanical Engineering in the design and maintenance of rotating machines, they are the amplitudes of vibration of the due rotor some residual unbalance during the passage for the critical speeds. The investigations o f the critical speeds of the rotating dynamic systems are of great interest, otherwise the effect of the resonance can cause noises; dynamic stresses, that take the fatigue and consequently premature failure of the structure and decrease of its useful life. The use of computational systems highly potent it allows to determine the response curves in frequency of the amplitudes of vibration of the rotor during the passage for the critical speeds. The mathematical model of the dynamic system rotating shaft-rotor-fluid film bearings have two degrees of freedom, considering sources of synchronous excitation and non-synchronous. The possibility of application of this work is patent, since, any existent mechanical system (machines tools, motors in general, generating systems of energy - hydroelectric, etc.) they are subject to those sources of excitation (forces). The determination and evaluation of the effects of those sources of excitation (through sensor of load and displacement) that act in the system they serve as non destructive techniques of the predictive maintenance of the equipment, allowing like this the control of its operation conditions and to the diagnosis of failure you didn't want. On the other hand, it is evaluated in this work the effect of a source of excitation non-synchronous acting in the system when the unbalanced rotor is rotating to a fixed rotation and that parameters can be monitored to reduce the amplitudes of vibration of the rotor, during the passage for the resonance and to improve the performance of the rotating dynamic systems.