A piston guiding element, rock drilling machine and method for supporting a front end portion of a percussion piston of a rock drilling machine. The piston guiding element includes a braking recess at its rear end. The element further includes at least one bearing sleeve, which is provided with two axially successive slide bearing sections. Hydraulic fluid is conveyed between the slide bearing sections via a feed system.

A piston guiding element, rock drilling machine and method for supporting a front end portion of a percussion piston of a rock drilling machine. The piston guiding element includes a braking recess at its rear end. The element further includes at least one bearing sleeve, which is provided with two axially successive slide bearing sections. Hydraulic fluid is conveyed between the slide bearing sections via a feed system.

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.

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 drilling rig and methods are provided for using multiple types of drilling when installing geothermal systems. The drilling rig can perform sonic drilling such as percussive sonic drilling and a type of non-sonic drilling. Control switching valves are added to the hydraulics of the drilling rig to selectively provide sufficient flow of hydraulic fluid to motors used in the multiple types of drilling, depending on which type of drilling is currently most efficient for the underground formation being drilled. The water pump and hydraulic motor for such have been designed to handle both types of drilling on a small drilling rig frame, thereby allowing for the drilling to occur in space-constrained environments. A method of recycling water used to remove cuttings during drilling to put back downhole is also provided.

A drilling rig and methods are provided for using multiple types of drilling when installing geothermal systems. The drilling rig can perform sonic drilling such as percussive sonic drilling and a type of non-sonic drilling. Control switching valves are added to the hydraulics of the drilling rig to selectively provide sufficient flow of hydraulic fluid to motors used in the multiple types of drilling, depending on which type of drilling is currently most efficient for the underground formation being drilled. The water pump and hydraulic motor for such have been designed to handle both types of drilling on a small drilling rig frame, thereby allowing for the drilling to occur in space-constrained environments. A method of recycling water used to remove cuttings during drilling to put back downhole is also provided.

A drilling tool is disclosed. The two ends of the drilling tool are respectively connected with an upper drilling tool and a drill bit. The drilling tool includes an axial striking part, a torsional striking part, and an auxiliary part. Under the combined action of a spring and a high-pressure drilling fluid, the hammer of the axial striking part generates an axial striking force to strike the upper housing; and the pendulum of the torsional striking part generates a torsional striking force to strike the lower housing. The reversing switch and the center tube are plugged together to simultaneously reverse torsion and axial striking forces, respectively. The high-pressure drilling fluid pushes the hammer and the pendulum to generate axial and torsional striking forces, respectively, to effectively increase the ROP and reduce the stick-slip phenomenon. The drilling tool is stable and reliable in a complex and changeable downhole environment.

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.

A modular reaming device incorporable into a tubular string. The modular reamer can include a tubular body having a first end and a second end and an internal bore, the internal bore extending longitudinally through the tubular body from the first end to the second end. The tubular body has an external surface with an outer diameter with cutting elements extending from the tubular body beyond the outer diameter of the tubular body for engagement with a bore hole sidewall. Each of the first and second ends have a coupling for coupling engagement with a tubular string.