HYDRAULIC DRIVE OF DEEP-WELL SUCKER-ROD PUMP Russian patent published in 2006 - IPC F04B47/04 

FIELD: oil producing industry.

SUBSTANCE: device is designed for recovery of oil from wells. Proposed hydraulic drive of deep-well sucker-rod pump contains hydraulic cylinder with piston and rod for connecting with sucker-rod string of deep-well pump. Pneumohydraulic accumulator is connected through separator to working liquid reservoir. Hydraulic distributor serves to deliver working liquid from reservoir by power pup into underpiston space of hydraulic cylinder or to return working liquid into reservoir. Piston reversing system includes upper and lower switches interacting with rod and electromagnetic hydraulic selector controlled by said switches and delivering working liquid to change over hydraulic distributor and separator. Hydraulic drive is furnished with additional pump and additional hydraulic distributor operated by electromagnetic hydraulic selector for alternate delivery of liquid from additional pump into pneumohydraulic accumulator or return of liquid into reservoir. Additional pump is installed on one drive with power pump. Excess pressure relief system is furnished with safety valves. Hydraulic distributor of power pump, electromagnetic hydraulic selector and safety valve are made with neutral position of working members of spools to provide starting mode of operation of power pump.

EFFECT: improved reliability of drive, simplified load compensation system, prevention of leaks of working liquid, increased efficiency of system.