Pump assembly

Abstract

A pump assembly ( 10 ) including two diesel engines ( 11 ) that are intended to operate at a relatively constant speed. The engines ( 11 ) each drive a variable displacement pump ( 12 ) that is preferably a swashplate pump. Fluid under pressure from each pump ( 12 ) drives an assembly ( 13 ) to pump a fluid such as a 95/5 emulsion, water and/or mud.

1 . A pump assembly including: a variable volume pump to deliver a drive fluid under pressure; a motor and pump device, said device including a motor portion and a pump portion, said motor portion being connected to said variable volume pump to receive said drive fluid so as to be driven thereby, said motor portion being adapted to receive a drive fluid under pressure, said motor portion including a cylinder and piston co-operating therewith to internally divide the cylinder into first and second variable volume motor chambers, the volume of said chambers being varied by movement of said piston longitudinally of said cylinder, a piston rod extending from said piston through said first chamber, a second piston rod, said second piston rod extending from said piston through said second chamber, a first pump cylinder operatively associated with said first piston rod to provide a first variable volume first pump chamber, a second pump cylinder, said second cylinder being operatively associated with said second piston rod to provide a variable volume second pump chamber; and a control assembly including a sensor to provide a signal indicative of the displacement of said piston, and a controller operatively associated with said sensor to receive said signal and to control said variable displacement pump to thereby control said motor portion and therefore output from said pump portion. 
     
     
         2 . The pump assembly of  claim 1 , wherein said variable volume displacement pump is a swashplate pump. 
     
     
         3 . The pump assembly of  claim 1 , wherein said device includes a priming pump to delivery fluid to the cylinders of said pump portion under pressure. 
     
     
         4 . The pump assembly of  claim 2 , wherein said device includes a priming pump to delivery fluid to the cylinders of said pump portion under pressure.