Pulsation-free positive displacement rotary pump

A pump comprising:

• two pistons in a rotor, the rotor being located inside two cavities forming a stator and being rotatable about an axis in contact with the stator, the rotor forming two opposite parallel pumping chambers in which the pistons respectively translate, driven by a fixed cam located inside the stator, the rotor having port for each pumping chamber through which a fluid can be aspirated into each of the pumping chambers during a filling movement of one of the pistons within the chamber and then expelled from each of the pumping chambers, during a pumping movement of one of the pistons within the chamber, through the port for each pumping chamber,
• wherein the stator comprises a housing portion defining an inlet cavity alternatively connected by rotation of the rotor, synchronously with the piston pumping movements, to the port of each of the pumping chambers, an outlet cavity alternatively connected to the port of each of the pumping chambers, and two ports changeover transition areas located between the inlet and outlet cavities, the inlet and outlet cavities with their respective external port changeover transition areas located there between being arranged around the rotor axis.