Abstract: An axial-flow blood pump has a rotor suspended in ball-and-cup bearings which are blood-cooled but not actively blood-lubricated. The ball-and-cup structures are made of highly heat-conductive material and are in heat-transferring contact with heat-conductive stator blades that serve as heat sinks for the bearings. The ball-and-cup structures are radially much smaller than the stator blades. The ball-to-cup interface has so small a gap that the ball-to-cup structures present an essentially continuous surface to the blood flow.

Abstract: An axial-flow blood pump has a rotor suspended in ball-and-cup bearings which are blood-cooled but not actively blood-lubricated. The ball-and-cup structures are made of highly heat-conductive material and are in heat-transferring contact with heat-conductive stator blades that serve as heat sinks for the bearings. The ball-and-cup structures are radially much smaller than the stator blades. The ball-and-cup interface has so small a gap that the ball-to-cup structures present an essentially continuous surface to the blood flow.

Abstract: An implantable electric blood pump has a motor stator defining a cylindrical blood conduit, and a pump rotor in which the motor rotor is embedded. The pump rotor is conical at each of its ends and terminates at each end in a ball-and-cup structure washed directly by the pumped blood stream. Grooves may be formed in the ball-and-cup structure to enhance the heat-removing washing action of the blood stream. The pump rotor is nested in the stator blades to shorten the pump and wash the outlet bearing with a partially circumferential blood flow. Titanium-titanium carbide facing alumina are the preferred materials for the rotary-stationary interface, and the gap of the rotary-stationary interface is kept so small that no significant amount of blood serum can penetrate between the mating surfaces of the interface.