DOUBLE-ACTING SUBSURFACE HYDRAULIC MACHINE Russian patent published in 1999 - IPC

FIELD: lifting of liquid from well; subsurface hydraulic motors. SUBSTANCE: hydraulic machine has housing with cylinders whose pistons are coupled by rod. distributing mechanism with inlet valve and tappets, outlet valves and relief valves installed on common tappet is placed between cylinders. Rigid coupling of tappets with inlet valve and provision of grooves communicating valve space with spaces of outlet valves at end of working stroke of pistons precludes premature change-over of outlet valve before lowering of valve to its seat. Provision of additional channels through which space communicates with outlet valve spaces cuts down time taken for changing over of outlet valves as their section exceeds section of grooves and they open at the beginning of travel of outlet valves. EFFECT: simplified design, enhanced reliability of hydraulic machine in operation. 3 dwg