Rotary Blood Pump

Abstract

Various “contactless” bearing mechanisms including hydrodynamic, hydrostatic, and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. These design features may be combined. In one embodiment, a pump housing has a spindle extending from a wall of the pump housing into a pumping chamber defined by the pump housing. The spindle has a stepped portion adjacent the wall. In one embodiment, the stepped portion is defined by a change in spindle diameter. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

1 . A pump apparatus, comprising:
 a rotor comprising paddles located at a periphery of the rotor to generate hydrostatic thrust forces, the paddles distinct from any impeller blades.   
     
     
         2 . The apparatus of  claim 1  wherein the rotor further comprises a grooved bore for generating hydrostatic thrust forces during rotation. 
     
     
         3 . The apparatus of  claim 1  further comprising a plurality of drive magnets disposed within a non-bladed portion of the rotor. 
     
     
         4 . A pump apparatus, comprising:
 a rotor having grooves located at a periphery of the rotor, the grooves establishing hydrostatic thrust forces during rotation of the rotor.   
     
     
         5 . The apparatus of  claim 4  wherein the rotor further comprises a grooved bore for generating hydrostatic thrust forces during rotation. 
     
     
         6 . The apparatus of  claim 4  wherein the rotor has a surface geometry suitable for supporting a hydrodynamic bearing. 
     
     
         7 . The apparatus of  claim 6  wherein the surface geometry comprises a plurality of spiral grooves. 
     
     
         8 . The apparatus of  claim 6  wherein the surface geometry comprises a herringbone groove pattern. 
     
     
         9 . The apparatus of claim  18  further comprising a plurality of drive magnets disposed within a non-bladed portion of the rotor. 
     
     
         10 . A pump apparatus comprising:
 a rotor having a grooved bore structured for generating hydrostatic thrust forces during rotation.   
     
     
         11 . The apparatus of  claim 10  further comprising a plurality of drive magnets disposed within a non-bladed portion of the rotor.