Electromagnetic vibration absorber for torsional vibration in high speed rotational machine

Abstract

In this article, the vibration absorbing characteristics of electromagnetic (EM) vibration absorber in the rotational machine are studied. The stiffness characteristic and the damping characteristic of an EM vibration absorber are analyzed. The EM vibration absorber realizes its active controllability by tuning its stiffness coefficient and damping coefficient, and then generates the force and torque through controlling the radial tilting. The dynamic equations of rotational machine and EM vibration absorber are established, and their dynamic responses are analyzed. Theoretical analysis results show that the vibration response of rotational machine and its load rotor can be regulated by tuning the stiffness coefficient and the damping coefficient of torque generated by the EM vibration absorber. Experiments are conducted to verify the theoretical analysis result by measuring the displacement deflections of rotational machine at different rotational speeds with different damping coefficients and stiffness coefficients. Therefore, the vibration absorbing ability for torsional vibration of rotational machine is tunable by regulating the stiffness coefficient and the damping coefficient, and the control range for vibration can cover the whole working frequency of rotational machine. This method is promising to suppress the vibration of the rotational machine with high rotational speed.