SE538874C2 - Damping device for liquid-driven submersible drilling machine and liquid-driven submersible drilling machine including such damping device. - Google Patents

Abstract

The invention relates to a steam device for a hydrogen-powered lowering machine for damping the recoil from a drill bit (SA) attached to the machine, comprising a motor (2), a pressure-driven device (3) with a reciprocating device (8). on a posterior spirit, sk. neck (58), a shock in which the drill bit (SA) is rotatable and axially reciprocating, means (4) for effecting rotation of the drill bit (5,4), a recoil damper (40, 32), characterized by the means (4) for rotating the drill bit (öA) is coupled for direct operation of the drill bit neck (58), the drill bit being rotatably mounted in said shock (37) in the front end of the machining housing, the retraction damper (4G, 32) comprises a pressure wattage filled chamber (48, 49), that a pressure vessel cushion in the chamber inside is arranged to provide axial bearings (41) for the crown at its rotation and that the pressure fluid cushion is located in front of the means (4) for rotation of the drill bit. -. = <.-'-. - .- -t - e ~> 4 -fl lm- »f - e-. fl (fig. 1) kupa / ams.zacce.com / sites / sefcase / t ss4s7sc / 41 samsas / PM SÛGOSQSEOO / PM 50GQ59SEO0__2Gi 5-G5-Oöwi 50505 peak o patentkravdoox

Description

The present invention liquid-driven relates to a damping device for a submersible drilling machine according to the preamble of claim t. The invention also relates to a single-fluid submersible drilling machine comprising a damping device according to a patent for a damping device. l-hole drilling l rock is done with striking drilling. When submersible drilling with a so-called liquid-driven submersible hammer DTH (Down-The-1-lole), both rotation and axial strikes take place on a work tool in the form of a so-called drill bit by means of a combined percussion ooh drilling machine located inside the borehole. The submersible drill bit is attached at its rear end to a drill string drill string which can be constituted by a flexible unit so-called coil (soil) or a number of interconnected rigid sections of drilling rig. A machine housing included in the submersible drill comprises a percussion device driven by a pressurized liquid, usually consisting of water or bentonite emulsion, which is conveyed via an inner channel in the drill string from an outside borehole, at the ground surface, located a power source in the form of a so-called drilling rig. A hydraulic drive piston produces an impact force on the rear day or neck of the drill bit. The blow generates a single shock wave (energy) which via the drill bit generates such a large force that the rock in front of the drill bit is crushed. The crushed rock, called cuttings, is transported out of the drilling rig with consumed propellant for the drilling machine.

During hole drilling, it is important that the drill bit has as good contact with the rock as possible, and for this reason the drill bit is pressed continuously with a predetermined axial feed force forward towards the rock by means of the drilling rig. Due to the effect of the discharge force, the pin of the drill bit comes from, for example, cemented carbide on the furthest part of the drill bit, the so-called the drill bit in strong contact with the rock. the flattening force is transferred from the drill string to the machine nozzle of the submersible drill and on to the drill bit. The proximal drill bit is pushed forward by the percussion device, the rock is crushed by occurring impact energy, after which hole drilling is performed by rotation of the drill bit in combination with the forward feed force. The drill bit is rotated by means of a rotary motor ooh is rotatably received in an ohuok at the front end of the machine housing. The drill bit is accommodated in the said ohuck and is reciprocally guided in the axial direction by means of a spine or boom connection.

As a result of the impact energy that is transferred from the drill bit to the rock when it is crushed, a recoil force occurs, ie. a backward pressure reflex from the rock back to the drill bit. The pressure reflex contains harmful reaction energy which is led from the drill bit and further back through the submersible drill. In order to reduce as far as possible the harmful effects of said reaction energy, drilling machines of this type are usually equipped with a damping device. Under certain working conditions, the pressure reflexes that are returned can be 2 so strong that they can cause damage to the drilling rig. Damage can be avoided by reducing the power applied to the submersible drill, which means that the felling capacity is reduced.

In order to absorb or hydraulically dampen any pressure that occurs, modern submersible drilling rigs are equipped with damping devices that include one or more axially displaceable damping pistons where each damping coil is active in a pressure chamber with hydraulic fluid.

Devices are also known in which the damping coil has both the task of superimposing force from the machine head, drill bit and further towards the rock, and that damping-reflecting compressive forces from the rock towards the drill bit, the machine housing and further back. In these devices, the space behind the damping piston acts both as a damping chamber and a pressure chamber to provide feed force. The damping chamber can be connected to a shock absorbing hydraulic circuit which provides a suspension function which protects the drill mesh. In the case of a so-called double damper, the damping coil has two pressurized areas which are connected to each other via a choke gap. One of these areas is located in a confined volume, which acts as a choke damper and via a "tandem" effect, reflected energy converts the heat into the hydraulic fluid when passing through the choke gap.

A disadvantage of well-known damping devices for rock drilling machines is that, due to the relative location of the damping chamber far back in the far back of the drilling machine, they result in harmful recoil forces being allowed to pass through sensitive equipment such as sawmills and rotary motor for the work tool. A further disadvantage is the limited ability of the known devices to absorb axial touches, which is mainly due to the limited force-absorbing cross-sectional area of the formed pressure fluid cushion in a main axis of the radial alpine cross-section. It should be appreciated that the ability of the pressurized fluid pad to absorb occurring forces, to act as an axial bearing for the rotation of the work tool and to provide the required feed force to the rock depends on the ability to form and efficiently utilize the cross-sectional area of the pressurized fluid.

The felling capacity and the maximum effect with which hitherto known rock drilling machines can work is consequently limited to a level that depends on the risk of damage in the event of shaking during recoil forces occurring. By damping said forces as far forward in the rock drilling machine as possible and thus also as close to the working area in front of the drill bit as possible where the harmful pressure reflections are generated, it is possible to avoid the forces being transmitted backwards and reaching sensitive equipment such as percussion and a rotary motor.

From EP 0856637 At a damping device for a rock drilling machine is known. To dampen the recoil, a circular damping chamber is arranged in one of the drilling machines which is located relatively far back. More specifically, the damping chamber is located behind the rotatone motor as well as a rear end paiti or neck of the drill bit against which a bracing member included in a 1G 2G 3G 3 sieve works. The damping chamber provides a pressure fluid cushion which is delimited in the axial direction by a pair of separate damping coils arranged in the rear of the drill, which, viewed in the axial direction, have a front movable damping coil adjacent to the stationary damping coil. in the radii direction, the damping chamber is delimited by the siag plant machine for the siagkoiven.

From SE 392 830 a damping device is known which essentially corresponds to the above device in that the annular damping chamber's position is relatively narrowly behind the drilling machine. In this known device the pressure fluid cushion inside the damping chamber is used as an axial shaft for the rotation of the drill bit.

A first object of the present invention is therefore to provide a single damper device for a submersible drilling machine which is simpler and more efficient than hitherto known damper devices. A second object is to provide a damping device which can also be used to provide a forward driving force for the drill bit from the machine housing towards the rock. A third object of the invention is to provide a submersible drilling machine which is efficient and has a high felling capacity by allowing it to run with higher power than hitherto known submersible drilling machines.

These objects of the invention are achieved by a damping device for a liquid drive submersible drilling machine which has the features and characteristics stated in claim 1, as well as a liquid-powered submersible drilling machine which has the features and features stated in claim 12. Further advantages of the invention appear from the subclaims.

The utilization of directly driven drill bit, ie. a drill bit which is rotated by intermittent pressurization with driving fluid by a rotary motor, wherein said rotary motor is of so-called wing ~ according to the type of disc coil, and whose rotor body is arranged for direct operation of the drill bit neck, in combination with a damping device with a damping coil which is located in front of the saw rotary motor which the rear end of the drill bit or neck offers a number of advantages.

First, the damping coil with associated annular damping chamber can be piaceras relatively narrowly advanced in the drilling machine, i.e. in front of a rotary motor such as a sawmill and the neck of the drill bit against which the sawmill's koiv operates.

Secondly, an annular pressure chamber with relatively high effective driver area can be extended by utilizing the radial distance with the inner mantle of a circumferential portion of an outermost outer tube included in the submersible drill and the peripheral outside of a circumferential portion of the drill bit neck.

Thirdly, the damping coil and pressure chamber can be defined in the existing parts of the machine housing, with the chuck spinning coupling to the drill bit and a rear end piece of outer tube attached to the front end of the engine housing bypassing the shock, the force acting on the shock being reduced by the axia. 4 feed force from the machine housing towards the rock offered by the pressure medium in the damping chamber, partly the feed force on the drill bit which is led via the machine housing and is generated by the drilling rig.

Fourthly, thanks to a the furthest outer pipe is stationary fixed to the engine housing, ie. the drill bit is rotatably mounted in the outer tube by direct drive, can supply lines, sensors and other components required to control fluid flow to and from the pressure chamber behind the damping piston are easily integrated not only in the tubular casing but also in the outer tube. In the following, the invention is described in more detail with Paganization of an embodiment shown in the accompanying drawings; on which; Eg¿ shows a longitudinal sectional view through a front part of a submersible drilling machine according to the invention, wherein a drill bit included in the submersible drill is shown partly in a retracted position, partly in an alternative projecting position of a working stroke (crushing stroke) towards a rock surface in front of the drill bit, egg shows a longitudinal section through a rear part of the submersible drill according to fig. l, fi Lâ shows a cross-sectional view through a rotary motor included in the submersible drilling machine taken along the line lll-lll in fig. t. fi gi shows an enlarged longitudinal sectional view of a damping device included in the submersible drilling machine according to the invention viewed within the marked area lv in fig. 1 and in which figure a hydraulic wiring diagram is schematically shown which further explains the principle of operation of the damping device according to the invention. The pressure fluid driven submersible drill bit described in the following is based on the self-rotating type described in more detail in Swedish patent application No. 1450845-1 ooh to which reference is made. in the following. Lvled smooth / rotating refers here to a single-core drilling machine of the type in which stepwise indexing of the drill bit takes place by the effect of intermittent pressurization of a rotary motor with drive fluid, preferably a motor of the so-called wing or disc piston type, whose rotor body is arranged for direct operation of the drill bit.

The submersible drilling machine shown in Figs. 1 and 2 comprises a tubular machine housing 2 with percussion mechanism 3, a rotary motor 4 and a drill bit 5A which has a neck 55 at its rear end. lvied neck generally refers to the posterior part of the drill that receives impact energy as well as over-rotation and feed force. The rear part of the k / machine housing 2 has a back piece o which is intended to be connected to a drilling support in the form of a drill string (not shown) formed by interconnected rigid drilling sections or a flexible unit so-called. coil A pressurized drive fluid, for example water or suspension of bentonite clay and water, is led from a cancer cell (not shown) in the form of a drilling rig connected to the other end of the drill string via a central cinnamon 7 in the drill string for driving the sink drill. In needle drilling of rock R, the drill bit 5A is applied to a normally hydraulically generated forward axial feed force FZ of said drilling rig. Via the drill string, machine housing 2, the lead feed force FZ up to the pin of the drill bit 5A which is brought into contact with the rock R. The proximal drill bit 5A is closed by the percussion device 3, the rock R is crushed by occurring impact energy, after which drilling is performed by rotating l-läl drilling work against the rock is performed by repeating the above steps. The two parallel power arrows F2 in Fig. 1 denote the feed force of the drill bit 5A in the shaft direction from the machine housing 2 towards the rock R, and in a corresponding manner the power arrow Er denotes a subsequent recoil force, i.e. the backward-facing pressure reflex from the drill bit towards the machine housing that arises after each working stroke of the drill bit.

The percussion unit 3 is located in the rear end of the machine nose 2 and comprises a percussion piston 8 which is driven via the liquid flow. The percussion piston 8 is designed as a shaft with a shoulder A and a through-going channel 9. The liquid flow is led via a valve 10 which alternately opens and closes the flow when the percussion piston 8 is moved between a rear initial position and a front end position which the piston performs its stroke against a rear end portion 5G of neck neck 58. A front and rear pressure chambers 18A, 138 are pressurized and relieved alternately by the axial movements of the percussion piston 8. The lower end position of the percussion piston 8 has a seat S against which an outer shoulder A included in the percussion piston 8 bottoms. The drill bit 5A is attached via its diametrically narrower elongate rear drill neck 58 to a knuckle in the front end of the machine nose 2. The bore 58 has a continuous axial channel 17. The percussion piston 8 has a piston surface and is arranged to strike the rear end portion 5G of the drill neck 58. The percussion piston 8 is connected to the liquid flow which via the valve 10 alternately fills and empties said pressure chambers 18A, 188 with propellant under pressure. When the percussion piston 8 has made its stroke against the end portion 56 of the drill neck 58, the front ventricular chamber 13A is placed under low pressure. return stroke and returns to its rear initial position. The drill neck 58 has a spline connection which fits into a crown sleeve 37, which gives the drill bit 5A a controlled forward and reciprocating axial movement and the possibility of rotating inside the machine housing 2, accompanying the rotation of the rotary motor 4. l flg. 8 shows the rotary motor 4 arranged for direct operation of the drill neck 58. The rotary motor 4 in this case is of the wing or disc piston type of the type comprising a stator housing 22 and a cylindrical rotor body 23 enclosed therewith, a number of disc pistons 25 movable in radellar guide slots 24 running in annular latches 26 in the stator housing and which groove communicates with an inlet 2 ? respective outlet 28 for propellant. The rotary motor 4 is located for direct operation of the drill bit 58, between the end portion 5G of the pin and the percussion device 3 in such a way that the drill bit 58 runs axially through an opening in the center of the rotor body of the rotary motor 4. The drill neck 58 is connected in this way via a spline or boom joint 29 to allow the drill bit 5A to relative to the rotatlon motor. When moving in the shaft direction 6, the rotor body 23 of the rotary motor 4 rotates, the drill neck SB and thus the drill bit 5Amed follows in the rotation.

The liquid flow to the rotary engine 4 begins when the percussion piston 8 is in its rear exit position, the position when the percussion piston is closest to the connection 6. When the pressurized liquid flow reaches the percussion piston 8, the valve 10 is opened, part of the flow being directed to the rotary motor 4. A remaining part of the liquid flow is led to the percussion piston 8 which strikes the drill neck 5B. When the percussion piston 8 leaves the rear rear starting position and moves towards its front end position, the valve 10 closes a channel 25 which leads to a pressure chamber included in the rotary motor 4, whereby the rotary motor stops. Accompanying rotary motor 4 performs the percussion piston 8 its working stroke and strikes the drill neck 58, the drill bit 5A striking the rock R. When the percussion piston 8 moves backwards towards the rear position, and when its rear position the valve 10 opens again and the flow is directed to the rotary motor 4. alternating pressurization of the rotary motor 4 via the valve 10 in this way, coupled to the reciprocating stroke reciprocating movements 8, an intermittent pressurization of the rotary motor 4 and thus indexing or rotation of the drill neck SB and thus the drill bit 5A predetermined steps for hole drilling in the rock R.

In order in accordance with the present invention to reduce the harmful reaction energy designated Er in Fig. 1 from said pressure reflex, the submersible drilling machine is equipped with a single damping device. This damping device also has the task of generating a forward axial driving force F1, i.e. feed force from the machine housing 2 towards the rock R. The damping device also has a pressure fluid cushion which acts as an axial bearing and is enclosed by an intermediate drill bit and a machine housing, the drill bit being the rotatable part while the machine housing is stationary. The operation of said damping device will be described in more detail below. Again to Fig. 1 an outer tube 32 is fixed in the front part of the tubular machine housing 2 which, since it is stationary, can be said to form a front part of the tubular machine housing 2, i.e. the hammer housing. An end sleeve 35 is screwed into the front end of the outer tube 32 via a thread. A crown sleeve 37 rotatably mounted in the outer tube 32 is provided with a spline coupling 38 acting on the drill neck 5B and together with an annular axial displaceable damping piston 40 forms part of a first axial bearing 41A which comprises a hydraulically effective damping cushion with enclosed pressure fluid. Said axial bearing 41 receives via a circumferential shoulder 42 arranged in the damping piston 40 against a similarly circumferential inner shoulder 43 of annular rear end piece 44 of the outer tube 32, which end piece has an opening 45 through which the drill neck 5B extends. As can be seen from Fig. 4, the damping piston 40 is coupled axially displaceably to the crown sleeve 37 via a coupling 46 and is "floating" in such a way that the tank moves back and forth between a front and a rear end position L1 and L2, respectively. It will be appreciated that said crown attachment 37 rotates together with the drill bit 5A relative to the outer tube 32.

As shown in the detail enlargement in Fig. T, the crown sleeve 37 thus forms part of a shock which is enclosed by the outer tube 32 and is rotatably mounted via a second axial bearing 418 in the outer tube together with the first axial bearing 41A. Lll 47 is denoted by a coil spring which is axially operative between the end housing 35 and the second axial bearing 418. lvled the term chuck is hereinafter generally referred to as the part or parts which constitute a bracket for a rotatable working tool. Fig. 4 and the detail enlargement in Fig. t show in more detail how the thrust bearing 41 is designed to form a double damper with concentrically located radially outer and inner annular chambers 48, 49 with pressurized piston members A1 and A2, respectively, which communicate with each other via a throttle gap 50. the pressure chamber 48 has a substantially larger effective piston area than the radially inner pressure chamber 49, i.e. At> A2.

The outer and inner annular pressure chambers 48, 49 are delimited between washable telescopically displaceable parts consisting of the damping piston 40 mentioned at the opposite ends and a rear end piece 44 of the outer tube 32 formed with reduced inner diameter. In the radial direction the outer and inner pressure chambers 49 are delimited. the orifice gap 50, common to the inner jacket of the outer tube 32 and the peripheral outside the neck SB of the drill bit 5A. Due to the combined essential radial extension of the outer and inner pressure chambers 48, 49, carbon products A1, A2 are obtained which together offer an effective driving area not only to provide a forward driving force, i.e. feed force Ft to the rock but also to act as an axial bearing underbody 5A. rotation and dampen the rearward pressure reflex Er from the rock R that occurs after each stroke of the drill bit.

As best seen in Fig. 4, the damping piston 40 has a front end position designated Lt and a rear end position designated 1-2. When the dam piston 40 is in said front end position L, the outer and inner pressure chambers 48, 49 exhibit maximum volume. The front end position Lt of the damping piston 40 is limited by co-operation between an annular projection 52 radially inwardly directed from the damping piston inner jacket 52 and a ledge 53 formed at a transition to a diametrically thicker portion of the crown sleeve 37. The rear end position L2 of the damping coil 54 of the damping piston 40 which telescopically projects into a seat-forming ledge 55 of the rear end piece 44 of the outer tube 32, the inner diameter of the ledge being slightly larger than the outer diameter of the collar so that the above-mentioned annular throttle gap 50 is defined between the mating portions. 49 communicates. In the radially inner pressure chamber 49 there is a confined volume of hydraulic fluid, which acts as a throttle damper and converts the energy from the rearward pressure reflex Er to 8 heat in the hydraulic fluid when passing through the throttle gap 50 to the outer pressure chamber 48. Thanks to the area differences between A1, A2 it the inner pressure chamber 49 with the smaller area A2 to be drained first on its liquid content to the larger outer pressure chamber 48 with the area A1 via the throttle gap 50.

Similarly, the two concentrically located radially outer and in-ring pressure chambers 48, 49 with the piston articles A1 and A2, respectively, offer a hydraulically generated forward feed force F1 which, by pressurization with hydraulic fluid, drives the drill bit 5A into contact with the rock R during heel drilling.

Fig. 4 further illustrates the operating principle of the damping device by means of a hydraulic wiring diagram. It should be understood that the hydraulic components described below are integrated in suitably shaped channels and recesses in the machine housing 2 of the submersible hammer and in outer tubes 32. The source 60 generally denotes a pressurized drive fluid intended for use as a hydraulic medium in the damping device pressure chamber 48,49. The propellant is intended to be led from the central channel 7 in which it should be understood that the propellant can be drawn from any suitable feed channel for pressurized propellant located near the front outer tube 32 in which the axially movable damping piston 40 is integrated.

The damping device is designed to control and monitor a damping pressure Dtpr, i.e. the pressure which must act on the damping piston 40 in order for it to function as a damping piston; and pressure F1pr to act as a feed piston and feed the drill bit forward to contact with the rock R. In this embodiment of the invention, the feed pressure F1pr and damper pressure D1pr are equal.

An accumulator 61 having a predetermined preload pressure is connected to the source 60 via a pressure reducing valve 62 or similar valve means which can maintain a constant pressure in the outlet and disconnects from the inlet when the pressure in the outlet exceeds a predetermined value. The accumulator 61 and the damping device pressure chamber 48, 49 are charged with propellant via said pressure reducing valve 62. The accumulator 61 acts as a single spring and depending on the selected performance of the accumulator a predetermined constant pressure is maintained in the damping device two pressure chambers 48, 49. the pressure reducing valve 62 and the outflow via a controllable throttle valve as a replacement for the accumulator 61.

The present damping device works as follows: Feed function: Pressurized propellant from source 60, ie. drive fluid taken from the central duct 7 flows via a suitably shaped channel in the engine housing 2 and the outer tube 32 (not shown) in the two hydraulic pressure chambers 48, 49 behind the damping piston 40. In this case a predetermined pressure F1pr is charged in the chambers 48, 49 as in in turn, by the action of the damping piston 9 40 both carbon products A1, A2 generate the required forward driving force, i.e. feed force F1for the drill bit 5A against the rock R. lt / feed force F1 is a product of the pressure receiving area A1 of the radially hydraulic outer pressure chamber 48 ooh the pressure receiving area A2 of the radially hydraulic inner pressure chamber 49. Consequently, the resultant driver 2 wants to attach the crown area A1 +? push this out against the second thrust bearing 418 iohuoken, with the force Ft. the clamping force FZ, which derives from the feed force of the rig, the pressure crown 5A against the rock R. By letting F1> F2, i.e. the feed force on the drill bit 5A deriving from the compressive force of the damping piston 40 will be greater than the feed force of the rig on the drill bit, the parts will be in the position according to Figure 1. The second thrust bearing 418 iohuoken is then relieved to FZ-F1, i.e. as the difference between the feed force of the rig and the reciprocating piston.

The damping function: in the outer and inner pressure chamber 48, 49 a corresponding pressure prevails, namely Dtpr which is the pressure acting on both the outer and inner piston parts A1 and A2 of the damping piston 40 when it is to function as a damping piston thereby generating a damping force DP to receive a resilient sat retard, the recoil force, ie. the posterior refractive pressure reflex Er which occurs after each stroke of the drill bit 5A. As described above, the damping piston 40 is axially displaceably coupled to the crown sleeve 3 via spline coupling 46? and is "floating" in such a way that it can move forward and back between said front l_1 and rear LZ end position. The sieve energy is transferred just as usual, through the impact piston's 8 tube travel energy via the drill bit 5A to the rock R. Reflectors from the drill bit go back to the crown attachment 37, ooh to the hydraulic drive area A1, A2 and the pressurized volume in the damping chamber. It is conceivable that the inflow to the drive area A1, A2 takes place through a rear valve, so that flow into this volume takes place freely with a large channel area, while the outflow takes place through a throttle drain. Ûä damping the reflex out hydraulically.

A substantial advantage of the present invention is that there is no metallic contact between the crown attachment 37 and the armor housing 2, in the direction the reflex goes, which substantially limits occurring vibrations to propagate backwards in the drill string.

When a pressure reflex Er from the rock R strikes back against the drill bit 5A, the crown sleeve 37 and thus also the damping piston 40 connected thereto is driven in the rearward direction, towards the rear end position 1-2. In this case, drive fluid is forced out of said inner pressure chamber 49 via the piston area A2 formed between the collar 54 of the damping piston 40 which telescopically projects into the seat-forming annular ledge 55 of the rear end piece 44 of the outer tube 32. Thanks to fluid, the outer chamber 50 is pressed and filled. the harmful energy in the pressure reflex Er or the recoil is attenuated by converting it to heat in the hydraulic fluid as it passes through the throttle gap 50. 1G As the external pressure chamber 48 is filled with propellant from the inlet chamber 49, propellant is forced into the accumulator 61 for temporary storage. As soon as the pressure reflex Er from the rock R has ceased, by the action of the pressure increase inside the accumulator 61, driving fluid is forced to flow backwards into the outer and the inner pressure chamber 48, 49 so that the original pressure state enters. The pressure Ftpr again prevails in the two pressure chambers 48 and 49, the damping coil 40 being driven forward towards the forward end Lt.

The invention is not limited to the one described above, the one shown in the drawings can be changed and modified in a number of different ways within the scope of the inventive concept stated in the appended claims. _. _. _ _- ~> <>. ~>. ~.-s «<-.-_- _...- -.-

Claims (1)

Device in a liquid-powered submersible drilling machine for damping the recoil from a nozzle crown (SA) connected to the machine, comprising a machine housing (2), a pressure-fluid drive percussion device (3) with a reciprocating percussion piston (8) arranged to release a slack end , and sk neck (SB) of the drill bit, a shock in which the eardrum (SA) is rotatable and axially forward and backwardly movably attached to the machine housing, means (4) for effecting rotation of the drill bit (SA), and feed force (FZ) from the machine nose (2) to the eardrum, a rekyi steamer, characterized by the means (4) for rotating the drill bit (SA) is connected for direct operation of the neck of the porn crown (SB), the drill bits being rotatably mounted in said onuok in the front end of the machine housing (2) via a single ring (37) , that the recoil damper comprises a pressurized fluid-filled chamber (48, 49), that the pressurized fluid cushion enclosed in the chamber (48, 49) is arranged to form axial bearings (41) for the drill bit upon its rotation. Device according to claim t, wherein in the chamber (48, 49) with the pressure fluid cushion formed therein is located in front of the means (4) for rotation of the drill bit (SA). Apparatus according to any one of claims 1-2, wherein the means (4) for effecting rotation of the drill bit (SA) comprises a wing-type disc piston type fluid motor of the type having a stator nose (22) and a cylindrical rotor body (23) enclosed therewith. which rotor body is directly coupled to the drill bit (SB) for operation thereof. Device according to claim 3, used in the drill bit (SB), opens axially through an opening in the center of the rotor body of the rotary motor (4) and is axially slightly reciprocally movably coupled to said rotor body. A device according to any one of claims 1 to 4, wherein the recoil mandrel pair comprises an annular torque damping piston (40) axially forwardly and reciprocally movably coupled to the neck (SB) shock and said damping piston having a rearwardly directed piston surface which is axially aligned with the front chamber (48, 49). surface of an annular end piece (44) of an outer tube (32) included in the machine light (2) through which end piece the drill neck (SB) extends via an opening (45). Device according to claim S, wherein the chamber (48, 49) is radially delimited by a circumferential portion of the inner jacket of the machine nose (2) and the peripheral outside of a circumferential portion of the earmold (SB). A device according to claim 5 or 6, wherein the chamber (48, 49) comprises two concentrically located radially outer and inner annular pressure chambers (48, 49) which communicate with each other via a throttle gap (59) wherein the the radial outer pressure chamber (48) reaches a larger effective piston area (A1) than the piston area (A2) of the radially inner pressure chamber (49). Device according to claim ö, wherein the cononentrically located outer and inner annular pressure chambers (48, 49) are delimited between two telescopically displaceable parts of which one part (54) comprises a part of the damping piston (40) and the other part comprises a part of the outer tube (32) end piece (44). Device according to any one of claims 1, 7, wherein the chamber (48, 49) is connected to a source of pressure fluid where the liquid consists of pressurized propellant for driving the lowering machine. Device according to claims t - 9, wherein pressure pressure actuating chamber (48, 49) is generated by a rearward pressure reflex (Er) from the upper crown, are arranged to receive resilience of a liquid accumulator (beer) connected to the chamber or to be led out of the fringe chamber passing a throttling valve. Device according to any one of claims 1 to 10, wherein the axially forward feed force (Ft) from the damping piston (49) acting on the crown sleeve (37) taken out in the unoccupied rotary pair bearing is greater than the feed force (FZ) which an out-of-porn drill has on the machine 2) via a loor string attached to a back piece (6) of the machine nozzle. Liquid-driven submersible porn machine comprising, a machine nozzle (2) with a tryokfluid drive percussion device (3), a drill bit (5A), a reciprocating percussion piston (8) arranged to be abraded on a rear end, so-called borrnaoke (SB) of the porn crown, an onuok in which the ear crown (öA) is rotatable ooh axielite forward and reciprocally movably attached to the machine nozzle, means (4) for effecting rotation of the ear crown (SA), a recoil damper, sensing dav means ( 4) for rotation of the earmold crown (SA) is coupled for direct operation of the earmuff crown (58) wherein the drill bit is rotatably mounted in the front end of said onuok imasklnnus (2) via a crown sleeve (37), that the recoil damper comprises entry and liquid-filled chamber (48, 49). , that a pressure fluid cushion enclosed in the chamber is arranged to form axial layers (41) for the drill bit during its rotation and which pressure fluid cushion is formed in front of means (4) for rotation of the drill bit. vgwwa fi-.fi w a _. u u -.- »and-a