Forward support rotating assembly (11) for a snapping roll (13) of a snapping unit (23) of a combine harvesting machine comprising: a frontally open axial seat (15) provided in the snapping roll (13) and having an inner circumferential abutment edge (17) a cylindrical support pin (19) extending axially in the seat (15) and being integral with a support bracket (21) for fixing the assembly (11) to a snapping unit (23) a sliding element (25) interposed between the support pin (19) and the seat (15) a labyrinth seal element (37) comprising a cylindrical ferrule (39) which has a labyrinth cross section and in which there is defined an inner annular seat (39a) and an annular packing seal (41) received in the annular seat (39a) and radially contacting the outer surface (29) of the cylindrical support pin (19) wherein the labyrinth seal element (37) frontally seals the seat (15) with respect to the outside.
