Peristaltic pump

Abstract

A peristaltic pump with three coaxial cylindrical components; a high-modulus rod contained within a piezoelectric tube, which in turn is contained within a cylindrical pressure casing, which may the casing of a hydraulic cylinder. The casing is filled with ERF. The piezoelectric tube has a plurality of electrode bands attached to its outer surface and is coated on its interior with an electrically conductive material. The electrodes are voltage-activated to cause certain portions of the tube to expand and others to contract, resulting in peristaltic action. The applied voltage also causes the ERF to form a gel state both inside and outside of the piezoelectric tube. A second embodiment includes a second set of electrode bands added to the interior of the casing, and a third set of electrode bands is added to the outside of the high-modulus rod. A method of incorporating the peristaltic pump into the piston of a hydraulic cylinder thereby forming a self-contained electrically-powered hydraulic actuator. An improved power supply that switches the polarity of the electrodes in a stepped fashion by transferring the associated charge through an inductor and drawing lost energy from a voltage source.

I claim:  
     
         1 . A peristaltic pump comprising: 
 a pressure casing having first and second ends;    a piezoelectric tube having first and second ends;    said tube disposed within said casing;    a high modulus rod have first and second ends;    said rod disposed within said tube;    spacers at said first and second ends of said tube and rod;    said spacers maintaining said tube and rod in coaxial alignment;    said rod and said tube defining a first annular gap therebetween;    said casing and said tube defining a second annular gap therebetween;    said casing filled with an electrorheological fluid.    
     
     
         2 . The pump of  claim 1  further comprising a first plurality of electrode bands, said bands on the exterior of said tube.  
     
     
         3 . The pump of  claim 1  further comprising a power supply, said power supply electrically connected to said pump.  
     
     
         4 . The pump of  claim 1  wherein said spacers comprise fluid passages.  
     
     
         5 . The pump of  claim 1  wherein said tube comprises an inner surface, said inner surface coated with an electrically conductive material.  
     
     
         6 . The pump of  claim 1  wherein said casing comprises inlet and exit ports.  
     
     
         7 . The pump of  claim 1  further comprising a second plurality of electrode bands, said bands on the interior surface of said casing.  
     
     
         8 . The pump of  claim 1  further comprising a third plurality of electrode bands, said bands on the outer surface of said rod.  
     
     
         9 . A peristaltic pump comprising: 
 a pressure casing having first and second ends;    a piezoelectric tube having first and second ends;    said tube disposed within said casing;    a high modulus rod having first and second ends;    said rod disposed within said tube;    spacers at said first and second ends of said tube and rod;    said spacer and maintaining said tube and rod in coaxial alignment;    said rod and said tube defining a first annular gap therebetween;    said casing and said tube defining a second annular gap therebetween;    said casing filled with an electrorheological fluid;    a first plurality of electrodes bands, said bands on the exterior of said tube;    a second plurality of electrode bands; said bands on the internal surface of said casing; and    a third plurality of electrode bands; said bands on the outer surface of said rod; and    a power supply, said power supply electrically connected to said pump.    
     
     
         10 . The pump of  claim 9  further comprising a power supply, said power supply electrically connected to said pump.  
     
     
         11 . The pump of  claim 9  wherein said spacers comprises fluid travel passages.  
     
     
         12 . The pump of  claim 9  wherein said tube comprises an inner surface; said inner surface coated with an electrically conductive material.  
     
     
         13 . The pump of  claim 9  wherein said casing comprises inlet and exit ports.  
     
     
         14 . A hydraulic system comprising: 
 a peristaltic pump;    a pressure casing having first and second ends;    said pump disposed within said casing;    said casing filled with an electrorheological fluid;    an actuator rod;    said rod disposed within and passing through, the ends of said casing;    said pump connected to said rod;    said pump operable to actuate said rod.    
     
     
         15 . The system of  claim 14 , further comprising a plurality of support plates, said pump connected to said rod by said support plates.  
     
     
         16 . The system of  claim 14  further comprising a power supply, said power supply electrically connected to said system.  
     
     
         17 . A power supply for use with an electrical system comprising: 
 a plurality of capacitors;    said capacitors electrically connected in parallel;    a plurality of capacitor switches;    an inductor;    said plurality of capacitors connected in series with said inductor via said capacitor switches; and    a voltage source;    said voltage source connected across said inductor via first and second voltage switches.    
     
     
         18 . The power supply of  claim 17  whereby said capacitors comprise an electrode band and a portion of a piezoelectric tube.  
     
     
         19 . The power supply of  claim 17  wherein said capacitor switches are triacs.  
     
     
         20 . The power supply of  claim 17  wherein said voltage switches are triacs.