Abstract
Vibration characteristics of a rotor with a ball balancer are investigated. It is shown that , when balls more than 3 are installed, infinite number of solution for the ball positions are obtained although the automatic balancing is attained. When the rotor is accelerated, the balls rotate in the rotor with satisfying the balancing condition. The almost periodic motion which is the major defect of the ball balancer can be decreased by making partitions in the rotor. When more than 3 partitions are used, the rotor is balanced for any position of the unbalance. When 2 partitions are used, the rotor is not balanced for some range of unbalance.
