volumetric pump bellows

The present invention relates more particularly to a volumetric pump, in particular a positive displacement pump having a bellows structure suitable for miniaturization. Said positive displacement pump (20, 100) comprises: - at least three bellows (22) equally spaced about an axis called the axis of the bellows, - at least three pushers (26) adapted to move along respective parallel push pins the axes of the bellows to control, each reciprocation of a pumping bellows (22), said pushers (26) being guided in translation in the volumetric pump housing, - a motor (38) for driving an axial cam ( 34), whose axis of rotation is parallel to the axis of the bellows so that the arrangement of bellows, controlled by said axial cam of cam axis (A2) enables the miniaturization of said pump.