A kernel processing assembly includes a first roll supported in bearings on a first frame element and a second roll supported in bearings on a second frame element, that forms a slot with the first roll through which harvested crop can be conducted. A rotary bearing is arranged on the first side of the slot that retains the first frame element and the second frame element free to pivot against each other. A pre-load arrangement is arranged on the second side of the slot that pre-loads the first frame element and the second frame element against each other. The rotary bearing includes a shaft to which an eccentric is fastened that retains the first frame element free to pivot, and that the shaft is supported in bearings, free to rotate, relative to the second frame element, so that the width of the slot can be varied by rotating the shaft about its longitudinal axis.