Rotary Blood Pump With Opposing Spindle Magnets, Bore And Drive Windings

Abstract

Various “contactless” bearing mechanisms including hydrodynamic and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. In one embodiment, a pump apparatus includes a pump housing defining a pumping chamber. The housing has a spindle extending into the pumping chamber. A spindle magnet assembly includes first and second magnets disposed within the spindle. The first and second magnets are arranged proximate each other with their respective magnetic vectors opposing each other. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

1 . A method of pumping blood comprising:
 providing a pump having a housing, a rotor, a spindle, an axial magnetic bearing and at least one hydrodynamic bearing;   adjusting said rotor axially;   rotating said rotor;   supporting said rotor with said axial magnetic bearing;   exerting a force in an axial direction via said at least one hydrodynamic bearing; and,   thereby levitating said rotor.   
     
     
         2 . A pump comprising:
 a pump housing defining a pumping chamber;   the pump housing having a spindle extending into the pumping chamber;   a rotor having a bore,   the rotor configured to rotate about the spindle,   the rotor including an impeller comprising at least one blade;   a rotor portion of a magnetic bearing disposed within a non-bladed portion of the rotor;   a spindle portion of the magnetic bearing disposed within the spindle, wherein at least one of the rotor and spindle portions of the magnetic bearing comprises a first and a second magnet, wherein the first and second magnets are arranged proximate each other with their respective magnetic vectors parallel to each other.   
     
     
         3 . A controlled pump system comprising:
 a control system for controlling operation of a pump;   a pump comprising:
 housing having a pumping chamber and a spindle; 
 a rotor positioned around said spindle; 
 an axial magnetic bearing supportive of said rotor; 
 a rotor adjustment mechanism; 
 a hydrodynamic bearing generating forces in an axial direction when said rotor is in a rotating state; 
 wherein said axial magnetic bearing and said hydrodynamic bearing combine to levitate said rotor during rotation of said rotor; 
   a source conduit connected to an inlet of said pump; and,   a destination conduit to an outlet of said pump;   said control system.