HYDRAULIC HAMMER Russian patent published in 2003 - IPC

FIELD: equipment of percussion type with hydraulic drive intended for sinking and driving out steel piles. SUBSTANCE: hydraulic hammer includes tubular body with upper and lower flanges fitted with grippers to link body with pile under mode of pile driving out, striking mass mounted in body for reciprocating motion along body, power cylinder anchored on upper flange of body which rod-piston is joined to strike mass, pump of hydraulic drive of hammer with pressure and drain lines connected through hydraulic distributor to spaces of power hydraulic cylinder, dampers installed in upper flange of body. Hammer has two or more dampers coming in the form of damping hydraulic cylinders with plungers. Spaces of damping hydraulic cylinders are filled with elastic medium, plungers face striking mass and their butts are positioned for interaction with striking mass at moment of strike under mode of pile driving out. Spaces of damping hydraulic cylinders communicate with pressure and drain lines through non-return valve with direction of flow towards damping hydraulic cylinders. Each plunger of mentioned damping hydraulic cylinders has two outer cylindrical surfaces of different diameters and circular belt connecting them. Outer cylindrical surfaces are aligned with corresponding two inner cylindrical surfaces of damping hydraulic cylinder and with similar circular belt joining them. Surface of plunger of smaller diameter faces striking mass. Annular groove which space communicates with drain line is cut in surface of smaller diameter of each plunger or damping hydraulic cylinder bordering on circular belt. Each plunger and damping hydraulic cylinder carries seal on side of groove opposite to circular groove. EFFECT: enhanced functional reliability and prolonged service life of hydraulic hammer. 3 cl, 4 dwg