WELL PUMP HYDRAULIC DRIVE Russian patent published in 2007 - IPC F04B47/04 

FIELD: positive displacement hydraulic machinery.

SUBSTANCE: invention can be used for to drive pumps designed for lifting liquids from depth. Proposed hydraulic drive of well pump has working cylinder and auxiliary tandem cylinder with rod with pistons fitted on ends of rod and installed to form four spaces, namely, two piston spaces, first of which is connected with compressed gas source and second, through hydraulic distributor, is connected with pump and drain, and two rod spaces, first of which is connected through hydraulic distributor with pump and drain, and second one, with rod space of working cylinder to form closed hydraulic circuit, and system to compensate for leaks from said circuit. The latter contains plunger pump whose space is connected with suction line with check valve connected through hydraulic distributor with drive pump, and delivery line with check valve connected with closed hydraulic circuit. Plunger pump of leaks compensation system is made in from of pressure booster. Smaller diameter plunger is arranged in second piston space of tandem cylinder for engagement with piston of tandem cylinder. Plunger of larger diameter is arranged in space of plunger pump connected with suction and delivery lines.

EFFECT: improved reliability of pumping unit owing to provision of operation of pump to feed liquid into closed hydraulic circuit only in case of its deficiency in circuit.

1 dwg