New automatic ball balancer design to reduce transient-response in rotor system

Abstract

Ball-type automatic balancers are used to reduce vibrations in rotating machines due to the rotor's inherent imbalance. An automatic ball balancer, consisting of several balls moving freely in a circular race containing a viscous fluid, is used in various rotating machines to reduce rotor vibrations. A properly designed automatic ball balancer can effectively reduce vibrations at steady state. However, it increases vibrations at transient state compared with rotors without an automatic ball balancer. High vibration response at the transient state may shorten the machine's life and produce unpleasant feelings in humans. In this regard, this paper provides a new automatic ball balancer design that prevents increasing vibrations at the transient state. To analyze the present design's motion properties in comparison with the traditional design, a theoretical model with a five-ball automatic balancer is constructed. Governing equations of this theoretical model are derived using Lagrange's equations, and a simulation is conducted using Matlab. The theoretical model's stability is determined with various values of design parameters at the steady state. Consequentially, this paper provides engineering guidelines for designing reliable ball balancers. (C) 2013 Elsevier Ltd. All rights reserved.