Seed distribution element for precision seed drills, seed drill including said element

A kit for the retrofitting of seed distribution elements of precision pneumatic seed drills wherein the distribution elements are of the type including:

• a sowing disc which is rotated by a motor-driven transmission drive shaft at controlled speed,
• a housing with a fixed portion and a portion which is movable relative to the fixed portion and can be closed against the fixed portion,
• a seed collection chamber being defined in the fixed portion,
• a pneumatic suction chamber being defined in the movable portion,
• the sowing disc being interposed between the fixed and movable portions and having opposed surfaces delimiting the chambers,
• the sowing disc having at least one ring of selector holes extending between the opposed surfaces, and
• a seal which is arranged on the movable portion and is capable of sliding contact with the facing surface of the disc when the portions are closed against one another,
• wherein a pressure differential is provided between the opposed surfaces in the region of a circumferential segment of the ring of holes,
• wherein the kit comprises:
• the movable portion pre-assembled with:
• a thrust-bearing element of the sowing disc, which thrust-bearing element is supported rotatably in the movable portion in order to withstand at least some of the axial load produced by the disc on the seal.