An axial flow pump for a blood circulating pump for the circulation of blood, the rotor the rotor being constructed and arranged to impel blood in a downstream direction upon rotation of the rotor about its axis in a forward circumferential direction. The rotor is provided with hydrodynamic thrust bearing surfaces, each such thrust bearing surface being constructed and arranged to apply a hydrodynamic force to the rotor with a component of the force in the downstream direction upon rotation of the rotor in the forward circumferential direction.
