Double-plate rotary barrel pump

Abstract

The present invention relates to a rotary barrel pump ( 6 ) comprising two plates: a mobile plate ( 2 ) also driven by drive shaft ( 5 ) and a variable-inclination plate ( 7 ), the two plates ( 2, 7 ) being linked to one another by a pivot connection.

1 . A barrel pump comprising a casing and comprising, within the casing:
 a drive shaft,   a cylinder block comprising at least two circumferentially distributed compression chambers, the cylinder block being driven by the drive shaft,   a mobile plate,   at least two pistons in translation respectively in the compression chambers of the cylinder block, the pistons being driven by the mobile plate by means of connecting rods,   wherein in that the mobile plate is driven by the drive shaft and the barrel pump comprises a plate with variable inclination relative to the drive shaft, the mobile plate being in pivot connection relative to the variable-inclination plate about axis of the variable-inclination plate.   
     
     
         2 . A pump as claimed in  claim 1 , wherein the pivot connection between the mobile plate and the variable-inclination plate consists of means for supporting the loads and means for holding up the assembly of the two plates. 
     
     
         3 . A pump as claimed in  claim 2 , wherein the pivot connection between the mobile plate and the variable-inclination plate consists of a conical roller thrust and of a ball bearing. 
     
     
         4 . A pump as claimed in  claim 3 , wherein the conical roller thrust is arranged between an outer shoulder of the mobile plate and an inner shoulder of the variable-inclination plate. 
     
     
         5 . A pump as claimed in  claim 3 , wherein the ball bearing is arranged between an outer shoulder of the mobile plate and an inner shoulder of the variable-inclination plate. 
     
     
         6 . A pump as claimed in  claim 1 , wherein the mobile plate is driven by the drive shaft through a pin spherical joint. 
     
     
         7 . A pump as claimed in  claim 6 , wherein the pin spherical joint comprises a device for forming a pin spherical joint in form of a hollow revolution part comprising a substantially cylindrical inner surface and an outer surface having substantially the shape of a truncated sphere at both ends, the inner surface comprises at least one groove or one female spline, and the outer surface comprises at least one crowned spline. 
     
     
         8 . A pump as claimed in  claim 7 , wherein device for forming a pin spherical joint is mounted on the drive shaft by means of a key or a splined shaft, and the mobile plate is mounted on the device by means of at least one groove cooperating with the at least one crowned spline. 
     
     
         9 . A pump as claimed in  claim 6 , wherein the mobile plate comprises a partly spherical inner surface. 
     
     
         10 . A pump as claimed in  claim 1 , wherein the barrel pump comprises a means for controlling the inclination of the variable-inclination plate. 
     
     
         11 . A pump as claimed in  claim 10 , wherein the inclination control means comprises a worm drive system. 
     
     
         12 . A pump as claimed in  claim 1 , wherein the are connected to the mobile plate without friction pads. 
     
     
         13 . Use of the barrel pump as claimed in  claim 1  for a drilling operation, in particular for injecting drilling mud into a wellbore. 
     
     
         14 . A method for conducting a drilling operation, comprising injecting drilling mud into a wellbore using the barrel pump as claimed in  claim 1 .