The invention is directed to an arrangement for journalling large eccentric forces which are generated by a rotating eccentric assembly. One problem associated with the bearing arrangements of these forces is that the size of the bearing is extremely large which, in turn, results in shaft speed limits that are readily exceeded. By dividing the eccentric assembly into two or more tubular eccentric weights arranged coaxially in relation to each other and journalling these in separate bearings on shaft journals connected to the structure to which vibratory motion is to be imparted, a distribution of the eccentric forces is obtained together with a reduction of the bearing dimensions. The eccentric weights are driven by means of a drive rod arranged on a drive shaft interacting with the eccentric weights. The journalling arrangement and eccentric assembly can be part of a vibration arrangement for imparting vibratory motion to the roller structure of a compactor for compacting soil, asphalt or the like.