A rotary percussive hydraulic drill including: a body, a shank intended to be coupled to at least one drilling bar equipped with a tool, the shank including a coupling part comprising female coupling splines and male coupling splines which are angularly offset from each other with respect to an extension axis of the shank, a striking piston slidably mounted inside the body along a striking axis and configured to strike the shank, a rotation driving device which is configured to drive the shank in rotation about an axis of rotation substantially coincident with the striking axis, the rotation driving device comprising a coupling member disposed around the shank, the coupling member comprising male coupling splines and female coupling splines which are respectively rotatably coupled with the female and male coupling splines of the shank a front abutment surface which is fixed with respect to the body, the front abutment surfacebeing annular and extending around the shank, the shank being configured to abut against the front abutment surface so as to limit a displacement stroke of the shank forwards, wherein the shank includes an annular bearing flange which is provided on an outer surface of the shank and which includes an annular bearing surfaceconfigured to abut against the front abutment surface, and wherein each of the female and male coupling splines provided on the shank extends from the annular bearing flange and in the direction of the striking piston, each female coupling spline provided on the shank including a bottom surface and a connecting surface which connects the respective bottom surface to the annular bearing flange and which extends forwards away from the extension axis of the shank, the connecting surface of each female coupling spline provided on the shank being at least in part formed by a curved concave surface extending substantially in the extension direction of the respective female coupling spline and having a radius of curvature which is less than the radial height of each of the male coupling splines provided on the shank.

The invention relates to an impact piston device for an impact drill drive, comprising an impact piston, which is movably mounted in a piston housing so as to be reversible between a front striking position and a rear retracted position, the impact piston having at least one front pressurizing surface and at least one rear pressurizing surface, at least one front pressure chamber and a rear pressure chamber being formed together with the piston housing, a hydraulic fluid feed, a hydraulic fluid drain, a first control device, by which at least the rear pressure chamber for effecting the reversing movement of the impact piston is connected alternately to the hydraulic fluid feed and the hydraulic fluid drain, and a second control device, with which at least one stroke path of the impact piston within the piston housing can be adjusted, the first control device having an actuatable first control valve and the second control device having an actuatable second control valve. According to the invention, it is provided that the first control valve and second control valve are arranged in a common valve housing.

A percussion apparatus including a pressure regulating device comprising a regulating cylinder; a connecting channel opening into the regulating cylinder; a pressure regulating slide mounted movable in translation within the regulating cylinder and delimiting, with the regulating cylinder, a connecting passage having a passage section which varies according to the regulating position occupied by the pressure regulating slide; a biasing element configured to exert a prestress on the pressure regulating slide; and a prestress setting device configured to set a prestress exerted by the biasing element on the pressure regulating slide.

A percussion apparatus including a pressure regulating device comprising a regulating cylinder; a connecting channel opening into the regulating cylinder; a pressure regulating slide mounted movable in translation within the regulating cylinder and delimiting, with the regulating cylinder, a connecting passage having a passage section which varies according to the regulating position occupied by the pressure regulating slide; a biasing element configured to exert a prestress on the pressure regulating slide; and a prestress setting device configured to set a prestress exerted by the biasing element on the pressure regulating slide.

A hydraulic breaking hammer and method of supporting a percussion piston is provided. The breaking hammer includes a percussion device provided with a reciprocating piston. The piston is supported on a frame at its end portions by a first piston bearing element and a second piston bearing element. The second piston bearing element includes a collar sealing element facing towards a working collar of the piston. The piston bearing elements are easily mountable and dismountable separate components.

A hydraulic breaking hammer and method of supporting a percussion piston is provided. The breaking hammer includes a percussion device provided with a reciprocating piston. The piston is supported on a frame at its end portions by a first piston bearing element and a second piston bearing element. The second piston bearing element includes a collar sealing element facing towards a working collar of the piston. The piston bearing elements are easily mountable and dismountable separate components.

The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

The rotary-percussive hydraulic perforator a body; a shank; a striking piston configured to strike the shank and provided with a braking surface; a braking chamber configured to hydraulically brake the striking piston; a stop piston configured to apply a pushing force on the shank and provided with a bearing surface configured to abut against a stop surface provided on the body, so as to limit the stroke of displacement of the stop piston towards the shank. The rotary-percussive hydraulic perforator is configured such that the bearing surface and the stop surface are axially spaced apart by a predetermined spacing distance simultaneously when (i) the shank bears on the stop piston and is in contact with the striking piston, and (ii) the braking surface is located at an inlet edge of the braking chamber.

This percussion apparatus includes a striking piston mounted so as to be displaced inside a piston cylinder and arranged to strike a tool; and a guide bearing comprising a guide surface configured to guide the striking piston during the displacements of the striking piston in the piston cylinder. The guide bearing includes a centering device configured to center the striking piston in the piston cylinder, the centering device comprising centering chambers formed in the guide surface and distributed around the striking piston, each centering chamber being fluidly connected to a high pressure fluid supply circuit; and at least one discharge groove formed in the guide surface of the guide bearing and located proximate to at least one of the centering chambers, the at least one discharge groove being fluidly connected to a low pressure circuit.

A hydraulic rock breaking machine and an apparatus and method for monitoring operation of the same is provided. The apparatus includes at least one pneumatic sensor arranged for monitoring an inner space of the machine and at least one control unit configured to receive and process the pneumatic sensing data.