Affiliations: Storage Laboratory Samsung Advanced Institute of
Technology, P.O. Box 111, Suwon 440-600, Korea | Department of Mechanical Engineering, Yonsei
University, 134 Shinchon-dong, Sudaemun-ku, Seoul 120-749, Korea | Center for Information Storage Device, Yonsei
University, 134 Shinchon-dong, Sudaemun-ku, Seoul 120-749, Korea
Abstract: The automatic dynamic balancer is a device to reduce the vibration
from unbalanced mass of rotors. Instead of considering prevailing ball
automatic dynamic balancer, pendulum automatic dynamic balancer is analyzed.
For the analysis of dynamic stability and behavior, the nonlinear equations of
motion for a system are derived with respect to polar coordinates by the
Lagrange's equations. The perturbation method is applied to investigate the
dynamic behavior of the system around the equilibrium position. Based on the
linearized equations, the dynamic stability of the system around the
equilibrium positions is investigated by the eigenvalue analysis. The stability
analysis provides the design requirements for the pendulum automatic dynamic
balancer to achieve a balancing of the system. The efficiency of ball automatic
dynamic balancer, for reducing the total vibration of the system, is better
than one of pendulum automatic balancer, if the rotating speed is above
critical speed. However, pendulum automatic dynamic balancer can achieve
balancing even if the rotating speed is below critical speed. The time response
analysis demonstrates the stability analysis from computing the radial
displacement of the rotating system and the positions of pendulums.
Furthermore, in order to confirm the theoretical analysis, various experiments
are made on pendulum automatic dynamic balancer.
