Pump unit for a centrifugal pump and a centrifugal pump

A pump unit for a centrifugal pump, the centrifugal pump including the pump unit and a stator extending in an axial direction from a first axial end to a second axial end, a cup-shaped recess provided at the first axial end, into which the pump unit is capable of being inserted, the pump unit comprising:

• a pump housing with an inlet and with an outlet for a fluid to be conveyed;
• and
• a rotor arranged in the pump housing with a plurality of vanes configured to convey the fluid, the rotor rotatable about the axial direction, the pump unit configured for a non-contact magnetic levitation of the rotor and for a non-contact magnetic drive of the rotor by the stator, the plurality vanes of the rotor arranged around a central inlet area of the rotor, the rotor comprising at least one relief opening to generate a recirculation flow directed from a back side of the rotor facing away from the inlet in a direction of the central inlet area of the rotor, and the rotor further having a separating element arranged in the central inlet area, the separating element configured to redirect the recirculation flow in a radial direction perpendicular to the axial direction, the plurality of vanes, the separating element and the at least one relief opening of the rotor being a one-piece unit.