APPLICATION OF AUTOMATIC BALANCERS ON A FLEXIBLE-SHAFT ROTOR SYSTEM

To avoid large vibrations, high speed rotating machines have to be balanced precisely. When the imbalance varies with the working conditions, it is desirable to have a balancer that can suppress rotational vibrations automatically. Ball-type automatic balancers can effectively reduce imbalance vibrations of twoand three-dimensional rigid rotors. However, the study of the application of autobalancers to the flexible shaft rotor system is not complete. With the increasing speed of rotating machinery, the flexible deflection of the shaft becomes more and more significant. Consequently, it is essential to conduct a comprehensive investigation on the effectiveness and restriction of applying auto-balancers to the flexible shaft rotor system. This paper carries out a dynamical analysis of the auto-balancer-flexible shaft rotor system. We study the dynamical behavior of the system under different kinds of imbalance. For the convenience of modeling arbitrary imbalance, we first construct a finite element model of the rotor and then employ Lagrange’s equations to derive the governing equations. A rotating coordinate system is used as the reference frame so that the governing equations are autonomous. In this case, the equilibrium solutions can be analyzed conveniently. The effects of important parameters on the steady state behavior of the system are investigated.