Patent attributes
A pump (2) comprising a stator (4) and a rotor (6) axially and rotatably movable relative to the stator, the stator comprising a rotor shaft receiving cavity (18), an inlet (14) and an outlet (16) fluidly connected to the rotor shaft receiving cavity (18), the rotor comprising a shaft (24) received in the rotor shaft receiving cavity (18). The rotor shaft (24) comprises a cavity (39) receiving a piston portion (12) of the stator therein to form a piston chamber (42), a seal (44) mounted between the piston portion (12) and inner sidewall of the cavity (39) to sealingly close an end of the piston chamber (42). The rotor further comprises a port (38) fluidly connecting the piston chamber (42) to an outer surface (60) of the rotor shaft (24), the port (38) arranged to overlap at least partially the inlet (14) over a rotational angle α of the rotor corresponding to a pump intake phase, and arranged to overlap at least partially the outlet (14) over a rotational angle β of the rotor corresponding to a pump expel phase.
