Rotary pump with hydrodynamically suspended impeller
AssigneeVentrAssist Pty Ltd and University of Technology
InventorsPeter Andrew Watterson, Geoffrey Douglas Tansley, John Campbell Woodard
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Abstract
This invention relates to rotary pumps adapted, but not exclusively, for use as artificial hearts or ventricular assist devices and, in particular, discloses in preferred forms a seal-less shaft-less pump featuring open or closed (shrouded) impeller blades with the edges of the blades used as hydrodynamic thrust bearing and with electromagnetic torque provided by the interaction between magnets embedded in the blades and a rotating current pattern generated in coils fixed relative to the pump housing.
Claims26
A rotary blood pump having an impeller suspended solely hydrodynamically within a pump housing by thrust forces generated by the impeller during movement in use of the impeller as it rotates about an impeller axis, and wherein said thrust forces are generated by edges of said blades of said impeller;
- and wherein said edges of said blades are shaped such that a gap between distal edges of each blade and the adjacent pump housing at the leading edge of the blade is greater than at the trailing edge so that the fluid which is drawn through the gap experiences a wedge shaped restriction which generates a thrust.
A seal-less, shaft-less pump comprising a housing defining a chamber therein and having a liquid inlet to said chamber and a liquid outlet from said chamber;
- said pump further including an impeller located within said chamber;
- the arrangement between said impeller, said inlet, said outlet and the internal walls of said chamber being such that upon rotation of said impeller about an impeller axis relative to said housing, liquid is urged from said inlet through said chamber to said outlet, and wherein thrust forces are generated by said impeller;
- and wherein said thrust forces are generated by edges of blades of said impeller, and wherein said edges of said blades are shaped such that a gap is formed between an end of each blade and the adjacent housing and the gap at a leading edge of each of said blades is greater than at a trailing edge thereof whereby fluid which is drawn through the gap experiences a wedge shaped restriction which generates a thrust relative to said housing.
A method of hydrodynamically suspending an impeller within a rotary pump for support in at least one of a radial or axial direction, said method comprising incorporating a deformed surface in at least part of said impeller so that, in use, a thrust is created between said deformed surface and the adjacent pump casing during relative movement therebetween;
- and wherein said deformed surface includes a taper;
- wherein said taper is arranged so that there is a gap between a distal end of each blade of said impeller and the adjacent housing, and a larger gap at a leading edge thereof between said impeller and said pump casing than at a trailing edge thereof.
Dependencies are inferred from the claim text.