Positive displacement pump

Abstract

The present invention provides a novel method of actuation for valve-less positive displacement reciprocating pumps. It also allows for variation of pumping volume by altering the speed of the motor, typically by adjusting the voltage. Use of the valve-less piston allows for compact design and it simplifies the construction, thereby ensuring reliable service.

1 . A positive displacement piston pump in which said piston moves axially while rotating on the same axis as a motor shaft.  
   
   
       2 . The pump as described in  claim 1  in which the axial movement of said piston is actuated by a ramp.  
   
   
       3 . The pump as described in  claim 1  in which said piston is connected to said motor by a sliding coupler.  
   
   
       4 . The pump as described in  claim 1  in which said piston has a motor rotor directly mounted onto it.  
   
   
       5 . The pump as described in  claim 4  wherein said piston-and-motor rotor combination is encased hermetically.  
   
   
       6 . The pump as described in  claim 2  wherein the angle formed between said ramp and a plane perpendicular to said piston is less than 45 degrees.  
   
   
       7 . The pump as described in  claim 1  formed from ceramic materials.  
   
   
       8 . The pump as described in  claim 1  wherein said pump is hermetically-sealed from a motor.