LIFTING DEVICE HYDRAULIC DRIVE Russian patent published in 2005 - IPC

FIELD: oil producing industry; positive displacement hydraulic machines.

SUBSTANCE: invention is designed for use in positive displacement hydraulic machines including hydraulic or pneumatic devices setting into operation of oil-well sucker-rod pump intended for lifting liquids from depth. Hydraulic drive of lifting device has working cylinder whose piston is provided with unit for connection with lifting device and which divides working cylinder into two spaces. One of spaces is connected by main pipeline through main distributor with pump and drain. Piston travel speed adjusting unit and two control elements can be connected with piston in extreme position. Piston travel speed adjusting unit is made in form of additional pipelines to deliver and drain working liquid from space of working cylinder with additional distributors. Main and additional distributors are connected with control elements made in form of time relays.

EFFECT: possibility of adjustment of working cylinder piston travel by means of simple and reliable devices.

2 cl, 4 dwg