Pump

Abstract

There is disclosed a pump, in particular a reciprocating pump. In one embodiment, a reciprocating pump ( 10 ) is disclosed which comprises an actuating cylinder ( 12 ); an actuating piston ( 16 ) mounted for reciprocating movement within the actuating cylinder; a discharge cylinder ( 52 ); a sleeve ( 40 ) releasably mounted within the discharge cylinder, to thereby define an operating diameter of the discharge cylinder; and a discharge piston ( 30 ) coupled to the actuating piston and mounted for reciprocating movement within the sleeve to successively draw fluid into and discharge fluid from the discharge cylinder. There is also disclosed a sleeve for such a pump, and a method of changing output flow from such a pump.

1 . A reciprocating pump comprising: 
 an actuating cylinder;    an actuating piston mounted for reciprocating movement within the actuating cylinder;    a discharge cylinder;    a sleeve releasably mounted within the discharge cylinder, to thereby define an operating diameter of the discharge cylinder; and    a discharge piston coupled to the actuating piston and mounted for reciprocating movement within the sleeve to successively draw fluid into and discharge fluid from the discharge cylinder.    
   
   
       2 . A pump as claimed in  claim 1 , wherein the discharge piston is releasably coupled to the actuating piston.  
   
   
       3 . A pump as claimed in  claim 1 , wherein the discharge cylinder is releasably coupled to the actuating cylinder.  
   
   
       4 . A pump as claimed in  claim 1 , wherein the pump additionally comprises: 
 a second discharge cylinder;    a second sleeve releasably mounted within the second discharge cylinder, the second sleeve defining an operating diameter of the second discharge cylinder; and    a second discharge piston coupled to the actuating piston and mounted for reciprocating movement within the second sleeve, to successively draw fluid into the second discharge cylinder while discharging fluid from the first discharge cylinder, and to discharge fluid from the second discharge cylinder while drawing fluid into the first discharge cylinder.    
   
   
       5 . A pump as claim in  claim 4 , wherein the output from the two discharge cylinders is combined.  
   
   
       6 . A pump as claimed in  claim 4 , wherein the pump provides independent fluid outputs from the two discharge cylinders.  
   
   
       7 . A pump as claimed in  claim 4 , wherein the first and second sleeves are of different diameters, to define different operating diameters of the respective discharge cylinders.  
   
   
       8 . A pump as claimed in  claim 4 , wherein the second discharge sleeve has a diameter equal to that of the first discharge sleeve, such that the discharge cylinders are of the same operating diameters.  
   
   
       9 . A pump as claimed in  claim 4 , wherein the second discharge piston is releasably coupled to the actuating piston.  
   
   
       10 . A pump as claimed in  claim 4 , wherein the second discharge cylinder is releasably coupled to the actuating cylinder.  
   
   
       11 . A pump as claimed in  claim 4 , wherein the first and second discharge cylinders are located at opposing first and second ends of the pump.  
   
   
       12 . A pump as claimed in  claim 1 , wherein the sleeve forms part of a removable cartridge comprising the sleeve and a seal for sealing between the sleeve and the discharge cylinder.  
   
   
       13 . A pump as claimed in  claim 1 , comprising a locking collar for engaging with the discharge cylinder to locate and secure the sleeve against movement relative to the discharge cylinder, in use.  
   
   
       14 . A pump as claimed in  claim 1 , wherein the actuating piston is operable in response to a fluid pressure force provided by an actuating fluid.  
   
   
       15 . A pump as claimed in  claim 14 , comprising a main valve assembly for controlling supply of actuating fluid to the actuating piston.  
   
   
       16 . A pump as claimed in  claim 15 , wherein the main valve assembly is adapted for controlling supply of actuating fluid successively to one end of the actuating cylinder whilst permitting discharge of actuating fluid from the other end of the actuating cylinder.  
   
   
       17 . A pump as claimed in  claim 15 , wherein the main valve assembly comprises a valve housing and a reciprocating shuttle valve, the shuttle valve controlling the flow of actuating fluid to the actuating cylinder depending upon a position of the shuttle valve relative to the valve housing.  
   
   
       18 . A pump as claimed in  claim 15 , wherein the main valve assembly is provided separately from the actuating cylinder.  
   
   
       19 . A pump as claimed in  claim 15 , wherein the actuating cylinder comprises a plurality of fluid flow ports for fluid communication between the actuating cylinder and the main valve assembly.  
   
   
       20 . A pump as claimed in  claim 19 , wherein the actuating cylinder comprises a pair of main flow ports, for the flow of actuating fluid into and out of the cylinder, the main flow ports acting as inlets or outlets depending on a direction of movement of the actuating piston.  
   
   
       21 . A pump as claimed in  claim 19 , wherein the main actuating cylinder flow ports are in fluid communication with the main valve assembly through main valve assembly flow ports, for the flow of fluid between the actuating cylinder and the main valve assembly.  
   
   
       22 . A pump as claimed in  claim 17 , wherein in a first position, the shuttle valve facilitates supply of actuating fluid to a first end of the actuating cylinder and discharge from a second end, to facilitate movement of the actuating piston in a first direction.  
   
   
       23 . A pump as claimed in  claim 22 , wherein in a second position, the shuttle valve facilitates supply of actuating fluid to the second end and discharge from the first end, for movement of the actuating piston in a second, opposite direction.  
   
   
       24 . A pump as claimed in  claim 15 , wherein the actuating cylinder includes a pair of pilot valves for controlling operation of the main valve assembly.  
   
   
       25 . A pump as claimed in  claim 24 , wherein the pilot valves are provided at opposite ends of the actuating cylinder, and each include a valve pin protruding into the actuating cylinder enabling opening of the pilot valves.  
   
   
       26 . A pump as claimed in  claim 24 , wherein the pilot valves are each biased towards a closed position, and wherein the actuating piston is adapted to contact the pilot valves to open the valves.  
   
   
       27 . A pump as claimed in  claim 24 , wherein the pilot valves permit selective fluid bleed from the main valve housing.  
   
   
       28 . A pump as claimed in  claim 27 , wherein each pilot valve selectively permits fluid bleed from a respective end of the main valve housing.  
   
   
       29 . A pump as claimed in  claim 28 , wherein the pilot valves selectively open the main valve housing to atmosphere, to permit fluid bleed through respective bleed ports.  
   
   
       30 . A pump as claimed in  claim 24 , wherein a first pilot valve is coupled to a first end of the main valve housing, and a second pilot valve is coupled to a second, opposite end of the valve housing, by corresponding fluid lines.  
   
   
       31 . A pump as claimed in  claim 30 , wherein the pilot valves are each also coupled to a fluid pressure source such that actuation of the first pilot valve supplies fluid to the first end of the valve housing, to move the shuttle valve in a first direction and actuation of the second pilot valve supplies fluid to the second end of the valve housing, to move the shuttle in a second, opposite direction.  
   
   
       32 . A pump as claimed in  claim 25 , wherein the position of the pins relative to the actuating cylinder are adjustable to permit alteration of the distance of travel of the actuating piston.  
   
   
       33 . A pump as claimed in  claim 15 , wherein the main valve assembly further comprises a flow input valve for controlling supply of actuating fluid to the assembly, and wherein the flow input valve is adjustable for controlling the supply of fluid to the main valve assembly and thus to the actuating piston.  
   
   
       34 . A sleeve for a reciprocating pump, wherein the sleeve is adapted to be releasably mounted in a discharge cylinder of the pump, to thereby define an operating diameter of the discharge cylinder.  
   
   
       35 . A method of changing output flow from a pump comprising the steps of: 
 detaching a discharge cylinder from a pump;    releasing a first sleeve of a first diameter from location within the discharge cylinder;    inserting a second sleeve of a second, different, diameter into the discharge cylinder; and then    re-attaching the discharge cylinder to the pump.    
   
   
       36 . A method as claimed in  claim 35 , further comprising the steps of: 
 releasing a first discharge piston from the pump, the first discharge piston adapted for reciprocating movement within the first sleeve;    attaching a second piston sized to be received within the second sleeve; and then    re-attaching the discharge cylinder.