Magnetically driven rotor for blood pump

A pump for transferring fluids and comprising a pumping chamber with an inner periphery, an outer periphery and a central axis, inlet port means arranged in polar relationship to said pumping chamber and coaxially with said pumping chamber, an outlet port means arranged transversely and generally medially of said pair of inlet ports, a rotor assembly disposed within said pumping chamber and having a core portion with a dual conical configuration converging toward opposed polar regions and having an axis of rotation extending between said polar regions and arranged coaxially with the axis of said pumping chamber, magnetic driven means arranged on said rotor at radially spaced locations from said axis of rotation, electromagnetic drive means coupled to a source of energy and arranged to deliver rotational driving energy to said rotor assembly through said magnetic driven means;

• said rotor assembly comprising:
• (a) a rotor core portion defining a first surface of revolution having an outer peripheral surface and a central axis extending therethrough;
• (b) at least one shroud coupled to the outer surface of said rotor core portion with said shroud defining a second surface of revolution arranged coaxially with the central axis of said rotor core portion, said shroud having an inner surface spaced from the outer surface of said rotor core portion and defining flow channels disposed annularly inwardly and annularly outwardly of said second surface of revolution;
• (c) said rotor assembly having a density relative to the fluid being pumped therein of between about 0.1 and 0.9;
• (d) said second surface of revolution having a configuration with an axial length extending along said axis of revolution and defining the axial length of said pumping chamber disposed between said inlet ports;
• (e) with the diameter of said rotor assembly transverse to said axis of rotation defining a medial plane and being selected to provide a clearance between the outer surface of said rotor core and the inner surface of said pumping chamber, and with the magnitude of the clearance between said inner surface of said pumping chamber and the outer periphery of said rotor core ranging from slightly divergent to slightly convergent;
• and
• (f) the arrangement being such that the sole support for the rotor are the hydrodynamic forces created in the fluid being pumped, wherein the casing structure of the pump is free of rotor supporting members and bearings.