Pump having magnetic bearing for pumping blood and the like

A pump comprising a housing, a motor including a stator and a rotor within the housing, an inlet means to said housing, an outlet means to said housing, means attached to said rotor for forcing a fluid received from said inlet means through said outlet means, said rotor having a central portion and a pair of axially extending extensions, said extensions disposed relative to said stator to define a pair of gaps between said extensions respectively and said stator, said central portion having a diameter which is greater than diameters of said extensions respectively and disposed relative to said stator to define a pair of radially extending gaps therebetween, and means for magnetically suspending said rotor in a non-contacting relation with said housing, said suspending means comprising journal bearing means for bearing said rotor and including interactive magnetic means on each of said rotor and said stator on opposite sides of each of the axially extending gaps, and active thrust bearing means for bearing said rotor, said journal bearing means for each of the axially extending gaps comprising a first pair of permanent magnet ring means on said rotor extension and said stator respectively on opposite sides of the respective axially extending gap, means for providing a repulsive relationship between said first magnet ring means, said repulsive relationship means comprising an orientation of said first magnet ring means so that a north pole on one of said first magnet ring means faces a north pole on an other of said first magnet ring means, said journal bearing means further comprising a second pair of permanent magnet ring means on said rotor extension and said stator respectively on opposite sides of the respective axially extending gap, means for providing a repulsive relationship between said second magnet ring means, said repulsive relationship means comprising an orientation of said second magnet ring means so that a north pole on one of said second magnet ring means faces a north pole on an other of said second magnet ring means, said second magnet ring means disposed adjacent to said first magnet ring means respectively and having polarity in the opposite direction so that like poles on the first and second magnet ring means respectively are adjacent each other, and wherein said thrust bearing means comprises permanent magnet ring means on said rotor adjacent at least two radially extending gaps between said rotor and said stator, and means comprising a pair of electromagnetic ring means on said stator adjacent said gaps respectively for magnetically interacting with said permanent magnet ring means for both rotating said rotor and maintaining axial position thereof, said pair of electromagnetic ring means being wound for magnetically interacting with said thrust bearing permanent magnet ring means for both rotating said rotor and maintaining axial position thereof.

A pump comprising a motor, a housing including a stator for said motor, an inlet means to said housing, an outlet means to said housing, a rotor for said motor, means attached to said rotor for forcing a fluid received from said inlet means through gaps between said rotor and said housing and then through said outlet means, and means for magnetically suspending said rotor in a non-contacting relation with said housing, said suspending means comprising an axially centrally disposed extension of said rotor and a pair of axially outer radially extending extensions of said rotor and a plurality of radially extending extensions of said housing which are interleaved with said rotor extensions to define a pair of centrally disposed and a pair of axially outer radially extending gaps respectively between said rotor and said housing, journal bearing means for bearing said rotor and including magnetic means on each of said rotor and said housing and disposed in interactive facing relationship on opposite sides of each of the axially outer radially extending gaps, and thrust bearing means for bearing said rotor and having interactive magnetic means which is disposed on both said rotor and said housing and which is disposed alongside the centrally disposed radially extending gaps, and said motor having a bearing span which is at least about 2½ times greater than an average radius of distributed force.