Unbalance cells consist of a robust shaft with eccentric weights are attached to both ends. While stationary, the unbalance weights can be changed by adding or removing steel or lead weights. This consequently alters the strength of the unbalanced exciter and the oscillation amplitude of the vibratory equipment.
In the case of vibrating units with two drive strings, these must turn in a reciprocal manner and thus produce a linear oscillation.
In the case of vibratiing equipment with a single drive train, it generates a circular or elliptical oscillation.