Volumetric Pump

Abstract

The present invention relates to a volumetric pump that comprises an inlet section and an outlet section. The pump also comprises a first volume with variable geometry that is connected through a first suction valve to said inlet section and through a first delivery valve to said outlet section, and a second volume with variable geometry that is connected through a second suction valve to said inlet section and through a second delivery valve to said outlet section. There are also provided first means for varying the volume of said first volume with variable geometry and second means for varying the volume of said second volume with variable geometry, and actuator means of said first means for varying the volume of said first volume with variable geometry and of said second means for varying the volume of said second volume with variable geometry. Advantageously, said actuator means comprise a servo motor.

1 .- 9 . (canceled) 
     
     
         10 . A volumetric pump comprising:
 an inlet section;   an outlet section;   a first volume with variable geometry connected through a first suction valve to said inlet section and through a first delivery valve to said outlet section;   a second volume with variable geometry connected through a second suction valve to said inlet section and through a second delivery valve to said outlet section;   first means for varying the volume of said first volume with variable geometry;   second means for varying the volume of said second volume with variable geometry; and   at least one actuator configured to control operation of said first means for varying the volume of said first volume with variable geometry and for driving of said second means for varying the volume of said second volume with variable geometry, said at least one actuator comprising a servo motor.   
     
     
         11 . The volumetric pump of  claim 10 , wherein the at least one actuator comprises a brushless servo motor. 
     
     
         12 . The volumetric pump of  claim 11 , wherein the at least one actuator comprises a first brushless servo motor for operation of said first means for varying the volume of said first volume with variable geometry and a second brushless servo motor for operation of said second means for varying the volume of said second volume with variable geometry. 
     
     
         13 . The volumetric pump of  claim 10 , wherein said first means for varying the volume of said first volume with variable geometry comprises a first disc plunger and that said second means for varying the volume of said second volume with variable geometry comprises a second disc plunger. 
     
     
         14 . The volumetric pump of  claim 10 , wherein in operating conditions a reduction of the volume of said first volume with variable geometry corresponds to an increase of the volume of said second volume with variable geometry, and an increase of the volume of said first volume with variable geometry corresponds to a reduction of the volume of said second volume with variable geometry. 
     
     
         15 . The volumetric pump of  claim 10 , wherein in operating conditions said first and second means for varying the volume of said first and second volume with variable geometry operate in phase opposition. 
     
     
         16 . The volumetric pump of  claim 10 , wherein in operating conditions the fluid flow rate respectively entering/exiting from said inlet and outlet sections is substantially constant. 
     
     
         17 . The volumetric pump of  claim 10 , wherein the at least one actuator comprises a first actuator and a second actuator, and said first actuator and said second actuator each comprise:
 a servo motor;   a shaft, having a rotation axis connected to said servo motor, wherein said servo motor transmits to said shaft a rotary motion about said rotation axis; and   a slider mounted sliding on said shaft,   wherein said slider comprises means for converting said rotary motion into a reciprocating translational motion, so that a first direction of rotation of said shaft corresponds to a first direction of translation of said slider along said shaft, and a second direction of rotation of said shaft, opposite said first direction, corresponds to a second direction of translation of said slider along said shaft.   
     
     
         18 . The volumetric pump of  claim 17 , further comprising a control unit configured to:
 selectively reverse said direction of rotation of said first actuator and said second actuator to implement the respective reciprocating translational motions in phase opposition to each other; and   vary according to an acceleration/deceleration curve the respective reciprocating translational motions to obtain a substantially constant flow rate.   
     
     
         19 . A method of operating a volumetric pump comprising a first cylinder that is connected through a first suction valve to an inlet section and through a first delivery valve to an outlet section, a second cylinder that is connected through a second suction valve to said inlet section and through a second delivery valve to said outlet section, a first piston functionally inserted in said first cylinder and adapted to move with reciprocating motion to define a first volume with variable geometry, and a second piston functionally inserted in said second cylinder so as to define a second volume with variable geometry, the method comprising:
 via at least one actuator comprising a servo motor, selectively moving said first piston along said first cylinder to modify said first volume with variable geometry, and   via the at least one actuator, selectively moving said second piston to move along said second cylinder to modify said second volume with variable geometry.   
     
     
         20 . The method of  claim 19 , wherein the at least one actuator comprises first and second actuators and each of the first and second actuators comprise a servo motor, a shaft having a rotation axis connected to said servo motor, and a slider mounted on said shaft,
 the method comprising, for each of the first and second actuators:
 transmitting to the respective shaft a rotary motion about said rotation axis; and 
 converting said rotary motion into a reciprocating translational motion, so that a first direction of rotation of said shaft corresponds to a first direction of translation of the respective slider along said shaft, and a second direction of rotation of said shaft, opposite said first direction, corresponds to a second direction of translation of said slider along said shaft. 
   
     
     
         21 . The method of  claim 20 , further comprising:
 selectively reversing said direction of rotation of said first and second actuators to implement said reciprocating translational motion of said first and second pistons in phase opposition to each other; and   varying according to an acceleration/deceleration curve said reciprocating translational motion of each of said first and second pistons so as to obtain a substantially constant flow rate.