Patent ID: 8591202

Claim:
A positive displacement pump system comprising: a) a drive system comprising a windmill and a counterbalance assembly, the windmill being coupled to the counterbalance assembly via a gearbox assembly; b) a first pump configured to pump liquid from a deep well, the first pump comprising: i. two or more vertically aligned pumping chambers; ii. a reciprocating central discharge tube suspended from the counterbalance assembly, wherein the discharge tube extends through the pumping chambers and is in fluid communication with each pumping chamber; and iii. a valve assembly in each pumping chamber, the valve assembly comprising a piston which sealably and slidably surrounds the central discharge tube and separates each chamber into an upper sub-chamber and lower sub-chamber; and c) a second pump comprising: i. two or more vertically aligned pumping chambers; ii. a reciprocating central discharge tube suspended from the counterbalance assembly and extending through the pumping chambers and being in fluid communication with each pumping chamber; and iii. a valve assembly comprising a piston in each pumping chamber that surrounds the central discharge tube and separates each chamber into an upper sub-chamber and lower sub-chamber; wherein both first and second pumps are controlled and operated by the drive system and the discharge tubes are configured in such a way that the discharge tube of the first pump reciprocates in opposite direction to the reciprocation direction of the central discharge tube of the second pump.