Dynamic Vibration Absorber with Negative Stiffness for Rotor System

Abstract

To suppress the vibration of a rotor system, a vibration absorber combining negative stiffness with positive stiffness together is proposed in this paper. Firstly, the negative stiffness producing mechanism using ring type permanent magnets is presented and the characteristics of the negative stiffness are analyzed. Then, the structure of the absorber is proposed; the principles and nonlinear dynamic characteristics of the absorber-rotor system are studied numerically. Finally, experiments are carried out to verify the numerical conclusions. The results show that the proposed vibration absorber is effective to suppress the vibration of the rotor system, the nonlinearity of the negatives stiffness affects the vibration suppression effect little, and the negative stiffness can broaden the effective vibration control frequency range of the absorber.

Magnetic Nonlinear Energy Sink for Vibration Attenuation of Unbalanced Rotor System

“…In [6], the authors developed another type of magnetic spring for rotor system. The magnetic spring is made up of ring type magnets, which can be divided into outer magnets and central magnets, as shown in Figure 1.…”

“…The repulsive magnet force in radial direction can be calculated by applying equivalent magnetic charge method. It is introduced in detail in [6], so it is only introduced briefly here. According to the equivalent magnetic charge method, the point charge of a point ( 2 , ) in plane 2 (as shown in Figure 1) can be calculated as…”

“…As shown in [6], the nonlinearity of the magnet spring can be ignored when distance ℎ is large. But when ℎ is small, the nonlinearity is rather large.…”

“…In torsional vibration suppression, centrifugal pendulum vibration absorbers [4] have long been widely used. In lateral vibration attenuation, many studies have also been carried out: [5] proposed a vertical vibration absorber which is mounted on the support of rotating Rayleigh beam; [6] developed a magnetic based dynamic absorber combining negative stiffness with conventional positive stiffness for rotor system vibration suppression; [7] adopted vibration absorber to eliminate the self-vibration of milling process.…”

Nonlinear dynamic behavior and stability of a rotor/seal system with the dynamic vibration absorber

“…Then, the DVA is mounted on the shaft by the rolling bearing with the frame in the horizontal and vertical directions, respectively. 22,24,30 So, it does not rotate with the rotor.…”