A seed distribution element (1) for precision pneumatic seed drills, includes:- a sowing disc (16) which is rotated by a motor-driven transmission shaft (20), at controlled speed, jointly with the shaft,- a housing (10) with a fixed portion (11) in which the shaft is supported and a portion (12) which is movable relative to the fixed portion and can be closed against it, with a seed collection chamber (15) in the fixed portion and a pneumatic suction chamber (17) in the movable portion,- the sowing disc (16) being interposed between the portions and having opposed surfaces (16a,16b) delimiting the chambers, and being provided with at least one ring of selector holes (23) extending between the opposed surfaces,- means (9) for producing a pressure differential between the opposed surfaces in the region of a circumferential segment of the ring of holes, including the pneumatic suction chamber, and- a seal (24) on the movable portion capable of sliding contact with the facing surface of the disc when the portions are closed against one another,- a thrust-bearing element (26) of the sowing disc, supported rotatably in the movable portion, in order to withstand at least some of the axial load produced by the disc on the seal.
