HYDRAULIC UNIT OF IMPACT ACTION Russian patent published in 2011 - IPC E21B1/26 

FIELD: machine building.

SUBSTANCE: unit consists of differential stepped piston-striker with case forming chambers of working and back strokes, of sleeve valve, of hydraulic pneumatic accumulator, of hydraulic channels, and of head and drain mains; also, unit is equipped with valve installed in case and forming three cavities. The first cavity is continuously communicated with the head main, hydraulic pneumatic accumulator and the chamber of backstroke. The second cavity is constantly connected with the chamber of the working stroke and alternately is connected with the head and drain mains. In the third controlled cavity there is installed a spring facilitating reliable valve closing at the end of the working stroke of the differential piston-striker. The second and the third controlled cavities of the valve are connected with the sleeve valve by means of the hydraulic channels; in the first position the sleeve valve connects the chamber of the working stroke with the drain main and the controlled cavity of the valve with the head main. In the second position the sleeve valve connects the controlled cavity of the valve with the drain main.

EFFECT: reduced local hydraulic losses during working stroke resulting in increase of energy of single impact and power of impact unit.

3 dwg