Dynamics Research And Control For A Rotor-bear-sealing System Under The Static Bias

The rotor-bear-seal system is a kind of the multiple degrees of freedom, and the couplednonlinear system, which can be applied to many fields. With the improvement of mediumpressure and rotational speed, the fluid vibration problem of large rotating machinery aboutseal clearance has been highlight out gradually, so the key technology of the development ofmodern large-scale mechanical is the control of fluid vibration. At present, most of thetheoretical study of the sealing system has been completed under the condition of withoutconsidering the static bias. In this article, we studied the dynamics behavior of the sealed fluidvibration model which journal in the seal chamber under the condition of considering thestatic bias. And it’s provides a theoretical basis for the installation error and elevation designof the rotating machinery. In the process of mechanical movement, it was found that in thehigh speed movement the rotor-bearing-sealing system wills loss its stability. And this wouldinterfere with the stability of the rotor-bearing-seal system. So it is necessary to study themovement of the rotor-bearing-seal system, and it can be provide a large amount of data inreal life. In this paper, we studied the influence of different parameters on the stability of therotor-bearing-seal system. Combined with numerical simulation the stability behavior of thesystem has been discussed. And the results show that the stability of the system is verycomplicated. In order to prolong the stable region of the system, we try to adopt to join theappropriate controller to control the chaotic behavior of the system, and extended the stableregion of the system.Main content of this paper are as follows:Firstly, we introduced the development history of rotor-seal system both at home andabroad, and then expound the purpose and significance of the research objects which wechoose. We illustrate the main problems and phenomena in rotor system, as well as theanalysis of the reasons which caused these problems and phenomena.Secondly, we studied the dynamics model of the rotor-bearing-seal system under thecondition of considering the static bias, and analyzed the different systems through thenumerical simulation. Combining with the bifurcation diagram, the maximumLyapunov-exponent spectrum, Poincaré sections, phase diagram and time history, the complexdynamic behavior of system has been investigated. This paper mainly studies as follows:Considered the rotor-bearing-seal system which under the influence of the differenteccentricity, system stiffness ratio and the rate of static bias.Finally, we conducted chaos control for the rotor-bearing-seal system. We are adding acontrol items to the system, and conducted numerical simulation for the system. We analysisthe bifurcation diagram of the system before and after the control, study the effect of controlitems, and make the delay of chaos. Considering the stiffness changes will affect the system,so our focus is to make stiffness can satisfied our values. Through the numerical simulation, we can get the bifurcation diagram of the system before and after control. The studyconcluded that the different control methods on the system have different behaviors.Therefore, when we select the controllers, we should first observe whether the control methodof the system is the most effective.