Research On Vibration Suppression Of Rotor System Using Dynamic Vibration Absorber And Automatic Ball Balancer Specialty: Mechanical Design And Theory Name: Zhu Guangyuan

Many modern machinery such as generator sets,aero engines,centrifugal compressors,boiler fans,machine tools,etc.are rotating machinery with rotors as the main components.The rotor will be unbalanced due to various reasons.The unbalanced force will cause the deflection and internal stress of the rotor during rotation,which will cause vibration and noise of the machinery and have a bad impact on the normal operation of the rotating machinery.One way to solve the problem of unbalanced vibration of the rotor is to use a ball automatic balancing device.It can completely eliminate the unbalance above the critical speed,but there is still a large amplitude resonance response near the critical speed and even cause unstable self-excited vibration.Considering that the dynamic vibration absorber has the characteristics of greatly reducing the structural resonance response,this paper uses the vibration absorber to overcome the defects of the ball balance device and improve its working performance in the critical speed region.Firstly,the working mechanism of ball balancing device controlling rotor unbalanced vibration is studied.The dynamic equation of the balance ball-rotor system is derived by Lagrange equation.Through theoretical analysis and numerical calculation,the influence of the position of the two balls on the automatic balance performance is studied,and its amplitude frequency and phase frequency response characteristics are analyzed.Secondly,the vibration absorption mechanism of dynamic vibration absorber controlling rotor unbalanced vibration is studied.Based on Newton ’s second law,the dynamic equation of the vibration absorber-rotor system is derived.Through theoretical analysis and numerical calculation,the influence of main parameters on the vibration absorption effect is studied.Finally,the amplitude change of the system during the transient process of the rotor angular velocity change is investigated.Finally,the characteristics and laws of controlling rotor unbalanced vibration when two vibration suppression methods are used together are studied.The dynamic model of the rotor system with vibration absorber and ball balancing device is established.The steady-state amplitude expression is solved,and the influence of each parameter on the amplitude-frequency curve is obtained.The dynamic response and vibration suppression effect of the rotor in the transient process considering angular acceleration are studied by numerical simulation.Through the amplitude comparison of the original rotor,the use of vibration absorber,the use of ball balancer,and the combination of vibration absorber and ball balancer,the results show that the combination of the two schemes simultaneously absorbs the two advantages of the dynamic vibration absorber that can reduce the resonance peak and the ball balancer that can completely balance the eccentricity in the supercritical state,and has a significant vibration control effect.The feasibility and effectiveness of the two methods are proved.