A forward support rotating assembly of a combine harvesting machine is provided that has a frontally open axial seat provided in a snapping roll with an inner circumferential abutment edge, a cylindrical support pin extending axially in the seat and being integral with a support bracket for fixing the assembly to a snapping unit, a sliding element interposed between the support pin and the seat, a labyrinth seal element comprising a cylindrical ferrule, which has a labyrinth cross-section and in which there is defined an inner annular seat, and an annular packing seal received in the annular seat and radially contacting the outer surface of the cylindrical support pin. The labyrinth seal element frontally seals the seat with respect to the outside.
