Control vibration of imbalance Jeffcott rotor by magnetic absorber

Unbalance mass and imperfect bearings are the main sources of vibration in rotor dynamics systems. One way to decline and control of a rotor vibration is the use of magnetic absorbers. The magnetic absorber is used to control the position of the rotor and reduce its vibration. In this study, by applying the dynamic absorber system force and creating two new natural frequencies, the magnetic absorber brings the system out of the resonance. Moreover, in order to decrease the vibration amplitude, two different types of dynamics absorbers are designed in which they are checked by the magnetic absorber in a specific range of rotational frequency. In magnetic absorber controller system, the continuous force which is applied to the main system by mass absorber is restored in sixteen levels discontinuously. It is seen that the vibration amplitude is reduced 13% in the area of natural frequency in comparison to the magnetic absorber with discontinuous force. In this paper, two different mass ratios are considered for each one of the two absorber systems. It is observed that in the case of dynamic absorbers with higher mass ratio, rotor vibration amplitude and the maximum force amplitude of the dynamic absorber system decrease. This issue can increase the accuracy of magnetic absorber system in the renewal of the dynamic absorber system force and reduce consumption electrical energy of the control system as well.