Flushing element, jackhammer, and method

Abstract

A flushing element, a rock drill and a method for providing a flushing space around a shank adapter of a rock drill, the flushing element (19) surrounding a shank adapter (8) passing through the flushing element, the flushing element comprising a supply opening (49) for supplying flushing liquid to the flushing space (21) and at least two sealing housings (51) for flushing sealings (S, S2, S3), the flushing sealings being present on both axial sides of the flushing space, the flushing element further comprising a split configuration, whereby the flushing element is radially installable and removable.

Description

[Technical Field]

[0001] Background of the Invention The present invention relates to a flushing element for a rock drill, the flushing element being intended to be installed in a tool-side end portion of the rock drill, whereby the flushing element surrounds a shank adapter configured to pass through the flushing element.

[0002] The present invention further relates to a rock drill and a method for forming a flushing space around a shank adapter of a rock drill.

[0003] The field of the invention is more particularly defined in the preambles of the independent claims.

[0004] Various types of rock drilling rigs are used at mining sites or other work sites. The rock drilling rigs are equipped with one or more booms, with a rock drill arranged at a distal end of the boom. The rock drill includes an impact device equipped with an impact piston configured to provide an impact pulse to the drilling tool via a shank adapter. A flushing fluid is supplied through the shank adapter and the drilling tool towards the drill bit. A flushing housing is present around the shank adapter to enable the supply of the flushing fluid. Several drawbacks have been identified with known configurations, particularly with regard to the installation of the shank adapter. Summary of the Invention

[0005] It is an object of the present invention to provide a new and improved flushing element, a rock drill equipped with such an element, and a method for forming a flushing space around a rock drill shank adapter.

[0006] The flushing element according to the invention is characterized by the features characterizing the first independent device claim.

[0007] The rock drill according to the invention is characterised by the features characterising the second independent device claim.

[0008] The method according to the invention is characterized by the features characterizing the independent method claim.

[0009] The concept of the disclosed solution is that a flushing element is intended to form a flushing space around a shank adapter of a rock drill. The flushing element surrounds the shank adapter, which is configured to pass through the flushing element. The flushing element comprises a supply opening for supplying a flushing liquid to the flushing space and at least two sealing housings for flushing sealing. The flushing element has a split configuration, which allows the flushing element to be radially installable and detachable.

[0010] In other words, the split flushing element is configured to form an annular flushing space around the shank adapter and to provide axial and radial support for the flushing sealing. The structure includes a plurality of split seal housings and a split annular-shaped flushing space.

[0011] An advantage of the disclosed solution is that the disclosed structure of the flushing element does not restrict the use of various shank adapters. If the flushing element can be assembled around the shank adapter in the radial or lateral direction, the outer diameters of the various axial portions of the shank adapter can be sized more freely. The shank adapter is not installed in the traditional manner by axially pushing the shank adapter through the flushing structure. Due to the split structure and the lateral installation direction of the flushing housing, the outer diameters of the rotating, flushing, and connecting portions of the shank adapter can be sized independently of each other. More versatile design options can be applied.

[0012] In this document, the terms "segmented" and "segmented configuration" refer to a structure having a non-uniform rim or circumference. The structure may be radially divided or broken into two, three, or more sections or ring-shaped segments.

[0013] According to one embodiment, there are at least two flushing seals and sealing houses on both sides of the sealing space. In addition, one or both end portions of the flushing element can be equipped with end seals and end seal housings to prevent impurities from entering the interior of the flushing element.

[0014] According to one embodiment, the flushing element is an elongated split bushing having two halves with longitudinal mating surfaces, the halves integrally defining an axial opening within which the shank adapter can be installed, and the inner surface of the opening is equipped with a sealing housing.

[0015] According to one embodiment, the halves are secured to one another by a number of securing screws, in other words the halves are bolted together.

[0016] According to one embodiment, the halves integrally form a plurality of sealing grooves on the inner surface of the split bushing.

[0017] According to one embodiment, the mating surfaces of the halves have conical surfaces.

[0018] According to one embodiment, the flushing element is a split flushing housing with a cover element that is installable and detachable from the basic structure of the flushing housing. In other words, the split flushing housing is configured to form the front part of the rock drill. The front part is also known as the flushing head. The flushing head is installed at the front end of the body of the rotating device. In this embodiment, the split structure comprises a basic frame part and a removable cover piece.

[0019] According to one embodiment, the outer surface of the mentioned detachable cover element forms part of the outer surface of the rock drill, and the opposite inner surface of the cover element comprises half of a ceiling house.

[0020] According to one embodiment, the cover element and the flushing head comprise fastening surfaces in the longitudinal direction of the flushing head.

[0021] According to one embodiment, the axial length of the cover element corresponds to the axial length of the entire flushing head.

[0022] According to one embodiment, the flushing head or housing is equipped with a uniform, undivided frame structure. Thus, an elongated, sleeve-shaped flushing element with a divided structure is implemented. The bearing of the shank adapter is likewise given a divided structure. The front end of the rock drill can be designed to axially receive a shank module with a divided, pre-assembled flushing housing and bearing element. Depending on the structure of the flushing head, the pre-assembled module can be installed from the impact end or the tool end of the flushing head.

[0023] According to one embodiment, the disclosed solution relates to a rock drill. The rock drill comprises a body and an impact device for generating an impact pulse. There is a shank adapter for receiving the impact pulse and transmitting the impact wave as a stress wave to a drilling tool connectable to the shank adapter. A rotation device is arranged to rotate the shank adapter about its longitudinal axis during drilling, and flushing liquid is supplied to a flushing head or housing located at the forward end of the body. The flushing head comprises a flushing element surrounding the shank adapter, whereby the flushing element forms an annular flushing space for supplying flushing liquid through the shank adapter to the drilling tool. The flushing element is of a split structure and comprises two or more compatible components. The flushing element follows the features disclosed in this document.

[0024] According to one embodiment, the sealing is a split seal with at least one split line, which allows the split seal to be mounted laterally around the shank adapter, i.e., not axially like a conventional seal, so that the split seal can be mounted in the middle of the shank adapter even if the inner diameter of the split seal is smaller than the outer diameter of the shank adapter at both ends of the shank adapter.

[0025] According to one embodiment, the split seal is a single split rotary seal made of a polymeric material.

[0026] According to one embodiment, the split seal has a shaped cut, as opposed to a straight cut, that allows the ends of the seal to lock and seal together at the cut.

[0027] According to one embodiment, the cutting portion is V-shaped, or alternatively, the cutting portion may have, for example, an arrow-hook design or a ball-and-socket design.

[0028] According to one embodiment, the split seal has a double split design, whereby the split seal has two halves, allowing the rotary seal to be a segmented sealing ring.

[0029] According to one embodiment, the shank adapter includes a connecting head for connecting a drilling tool and a rotating portion at the opposite end for transmitting torque. The rotating portion includes a plurality of splines. Between the connecting head and the rotating portion is a flushing portion, the flushing portion including a lateral flushing opening at the connecting head end that contacts an axial flushing portion extending to the distal end of the shank adapter. The outer diameters of the connecting head and the rotating portion are larger than the outer diameter of the flushing portion. In other words, the shank adapter has a slim midsection between thicker ends.

[0030] According to one embodiment, the connecting head of the shank adapter comprises a shoulder equipped with an axial contact surface and a protruding axial portion equipped with a connecting thread. In this embodiment, the shoulder is configured to axially transmit the propagating stress waves between the impact device and the shank adapter. Shank adapters equipped with a shoulder, i.e., shoulder contact adapters, typically have a longer service life compared to so-called bottom contact shank adapters. This is because the temperature of the connecting thread of the shoulder contact adapter can be maintained at a lower level compared to the connecting thread of the bottom contact adapter. This solution makes it possible to use shoulder adapters without the need to use larger bearings and sealing surrounding the shank adapter. Furthermore, the disclosed solution provides an easy, fast, and convenient method for installing and removing the shank adapter and for replacing worn or damaged mechanical components surrounding the shank adapter.

[0031] According to one embodiment, the connecting head of the shank adapter is provided with a connecting thread having an outer diameter larger than the outer diameter of the flushing portion between the spline and the connecting thread. In this solution, a bottom contact shank is disclosed. However, the outer dimensions of the connecting thread of the bottom contact adapter can be freely sized without restricting the installation of the shank adapter, so that compared with current bottom contact adapters, the connecting thread can be larger than usual and therefore have higher durability.

[0032] According to one embodiment, the shank adapter is supported for axial movement by at least one split sliding bearing, in other words, the bearing of the shank adapter can be installed or removed transversely to the axial direction of the shank adapter.

[0033] According to one embodiment, the split flushing element comprises a bearing seat or housing for the split sliding bearing halves. There may also be a split flushing bushing equipped with a seat for sealing and a seat for the bearing component. If the structure comprises a cover element that can be laterally installed and removed, the sealing and bearing seats may be partially formed on the inner surface of the cover element. Alternatively, there may be a separate split bearing element, such as a split bearing bushing equipped with a bearing seat for the split bearing element.

[0034] According to one embodiment, the rock drill includes one or more sensors, sensor modules, or measurement devices located at a forward end portion of the rock drill, where the sensors have a split configuration such that they can be radially installed around the shank adapter in a manner similar to the disclosed sealing housing and bearing.

[0035] According to one embodiment, the sensor or components of the sensor are integrated to be part of the structure of the sealing housing having a split configuration.

[0036] According to one embodiment, the sensor is configured to detect stress waves propagating within the shank adapter. The sensor is a non-contact sensor and may be an inductive sensor, a capacitive sensor, or a sensor that detects changes in a magnetic field. Such sensors typically require the sensing components to be arranged around the object being sensed, which in this case is the shank adapter. If the structure of the sensor or sensing device can be divided into two, three, or more pieces, this facilitates sensor installation.

[0037] According to one embodiment, the disclosed solution relates to a method for providing a flushing space around a shank adapter of a rock drill, the method comprising: surrounding a middle portion of an elongated shank adapter with a flushing element to form a flushing space having an annular shape, sealing the flushing element to the shank adapter with at least two flushing seals supported on an inner surface of the flushing element relative to a sealing housing, using a split flushing element with at least two connectable components, and connecting the components of the flushing element laterally relative to the shank adapter.

[0038] According to one embodiment, the method includes pre-assembling a flashing element around a shank adapter and installing the combination of the shank adapter and flashing element as a single piece inside the rock drill - in other words, forming a pre-assembled shank module.

[0039] According to one embodiment, the above-mentioned pre-assembly may comprise a pre-assembled bearing element in addition to the flushing element.

[0040] According to one embodiment, the rock drill comprises separate, split bearing housings or modules configured to support the sliding bearing elements.

[0041] According to one embodiment, the bearing element referred to is an integral part of the split flushing element, which is therefore equipped with a bearing housing for receiving the split bearing element.

[0042] According to one embodiment, the mentioned split bearing elements are made of a sliding bearing material, which may for example be made of a suitable metallic bearing material.

[0043] According to one embodiment, a bronze alloy material is used as the sliding bearing material mentioned above, which may be, for example, tin bronze, lead tin bronze, aluminum bronze, or manganese bronze.

[0044] According to one embodiment, the disclosed method includes the following installation steps: installing a first component of the split flashing element, installing a shank adapter onto the first component, installing a flashing ceiling, and installing a second component of the split flashing element.

[0045] According to one embodiment, the disclosed flushing element and related segmented components can be used in any kind of hydraulic rock drill that uses the so-called tophammer principle. Although surface drilling is disclosed in this document only as an example of use, this means that the solution can also be used in underground drilling machines, bolting devices, exploration devices and any kind of device that performs tophammering.

[0046] The above disclosed embodiments can be combined to form suitable solutions having the required features of the above mentioned characteristics.

[0047] Some embodiments are explained in more detail in the accompanying drawings. [Brief explanation of the drawings]

[0048] [Figure 1] 1 is a schematic side view of a rock drilling rig for surface drilling. FIG. [Figure 2] FIG. 1 is a schematic diagram showing a hydraulic rock drill. [Figure 3] FIG. 2 is a schematic cross-sectional side view showing the front part of the rock drill. [Figure 4] FIG. 1 is a schematic side view showing a shank adapter equipped with a connecting head for making shoulder contact with a drilling tool. [Figure 5] FIG. 1 is a schematic side view showing a shank adapter equipped with a connecting head having an oversized thread surface. [Figure 6] 1 is a schematic diagram showing a flushing element comprising a sleeve-like body comprising two halves. [Figure 7] 7 is a schematic cross-sectional side view of the flushing element shown in FIG. 6. [Figure 8] FIG. 2 is a schematic partial cross-sectional side view showing a flushing head having a split structure. [Figure 9] 1 is a schematic view of a split sealing ring with a shaped cutout, viewed in an axial direction; FIG. [Figure 10] 1 is a schematic view of a split sealing ring with multiple cuts viewed in an axial direction; FIG. [Figure 11] 1 is a schematic diagram showing a split sealing ring in a lateral view with a shaped cut. FIG. [Figure 12] FIG. 1 is a schematic diagram showing a split bearing element comprising two halves. DETAILED DESCRIPTION OF THE INVENTION

[0049] For the sake of clarity, these figures illustrate in a simplified manner some embodiments of the disclosed solution, in which like reference numerals denote like elements.

[0050] FIG. 1 shows a rock drilling rig 1 intended for surface drilling. The rock drilling rig 1 comprises a movable bed 2 and at least one drilling boom 3 connected to the movable bed 2. At the distal end of the drilling boom 3, there is a drilling unit 4 equipped with a feed beam 5 and a rock machine 6 supported on the feed beam 5. A drilling tool 7 is connectable to the drilling machine 6. The rock drill 6 comprises a shank adapter 8 at its forward end FE for connecting the tool 7. The rock drill 6 further comprises an impact device 9 and a rotation device 10. The rock drill 6 can be moved on the feed beam 5 in a drilling direction A by a feed device 11. During drilling, an impact pulse is generated by the impact device against the rotating shank adapter 8, which transmits the impact pulse and torque to the drilling tool 7. A flushing fluid flow is conveyed through the hollow structure to the shank adapter 8 and further through the drilling tool 7 to the bottom of the borehole in order to flush out the cuttings from the borehole.

[0051] 2 discloses a rock drill 6 comprising a body 12, an impact device 9, a rotation device 10 and a gear housing. At the forward end FE of the body 12, a flushing housing 13 and a shank adapter 8 are mounted. A flushing fluid, such as water, is conveyed by a flushing channel 14 to the flushing housing 13 or flushing head.

[0052] The impact device 9 may comprise an impact piston 48 (shown in FIG. 4) for generating an impact pulse IP in the direction of impact against the shank adapter 8. The rotation device 10 and transmission means inside the gear housing rotate the shank adapter 8 about its longitudinal axis (R), as shown in FIG.

[0053] FIG. 3 very simply discloses the front end FE of a rock drill. The flushing housing 13 is equipped with a pre-assembled shank module 15, which includes a shank adapter 8 and a flushing element 16 assembled around the shank adapter 8. The flushing housing 13 may include a space into which the module 15 can be pressed in the mounting axial direction ID and locked in place, for example, by a flange 17. As can be seen, the ends of the shank adapter 8 have diameters D1 and D4 that are larger than the diameters D2 and D3 between them. Therefore, the shank adapter 8 cannot be axially mounted inside the frame 18 of the flushing element 19. Instead, the frame 18 has a split structure and includes two halves that can be mounted laterally to each other. In addition to the frame 18, the seals S1, S2, and S3, as well as the front bearing element 20, also have a split structure. Therefore, in the illustrated structure, the flushing element 19 includes a split frame, a split seal, and a split bearing. The frame 18 and seals S2, S3 together define a flushing space 21 around the flushing portion 22 of the shank adapter 8. Flushing fluid is supplied through supply openings 49 to the flushing space 21 surrounding the shank adapter 8 and further through flushing openings 23 in the shank adapter 8 to an axial passage 50 within the shank adapter 8 through which the flushing fluid 50 flows towards the drilling tool.

[0054] At least two sealing housings 51 are present on the inner surface of the flushing element 19 for receiving the flushing sealings S2, S3. The sealing housings 51 are located at a certain axial distance from each other on both sides of the flushing space 21. Furthermore, a sealing housing 52 is present for receiving the front sealing S1. The sealing housings 51, 52 may be sealing grooves or other suitable spaces.

[0055] In the disclosed solution, the diameter D2 of the bearing portion 24 may be smaller than the diameter D1 of the connecting head 25 of the shank adapter 8 and may also be smaller than the diameter D4 of the rotating portion 26. This is advantageous for the propagation of stress waves generated by the impact pulse of the impact device. At the connecting head 25 or connecting portion, a shoulder 27 may form the largest diameter D1. At the rotating portion 26, there may be a plurality of splines 28 designed to contact the rotating gears of the gearing housing. The larger dimension D1 at the connecting head 25 may be advantageous in terms of the durability of the connection, while the larger dimension D4 at the rotating portion 26 may be advantageous in terms of the transmission of torque.

[0056] The pre-assembled shank module 15 disclosed in Figure 3 can be supported relative to the flushing housing 13 in several alternative ways. For example, it is possible to install the module 15 in the opposite direction to the disclosed installation direction ID. Another possibility is to design the flushing housing with an openable cover or split structure, whereby the module can be installed laterally in a single piece.

[0057] FIG. 3 further discloses that the shank adapter 8 may be provided with a surface 29 intended to retract the shank adapter 8 and the connected drilling tool rearward by a feed device of the drilling unit upon completion of drilling.

[0058] FIG. 4 shows a shank adapter 8, in which the connecting head 25 has a shoulder 27 and a connecting thread 30. The shoulder 27 has an axial surface 31 for transmitting shock waves. A clearance exists between the distal end 32 of the shank adapter 8 and the drilling tool 7. The diameters D1 and D4 are larger than the diameters D2 and D3 between them. The diameters DP and D3 of the piston 33 may be substantially equal. At the rear end of the shank adapter 8, there may be a section for receiving the shock pulse, equipped with an impact surface 34. The diameter D5 of the impact section may likewise be equal to or substantially equal to the diameter DP of the striking piston 33. The advantage of this is therefore good propagation of stress waves through the shank adapter 8.

[0059] Figure 4 discloses a so-called shoulder-contact shank adapter 8, whereas Figure 5 discloses a so-called bottom-contact shank adapter 8. In Figure 5, the distal end 32 of the shank adapter 8 is fastened to the drill tool 7 by a threaded portion 30. The diameter D1 of the threaded portion 30 may be dimensioned to be larger than that of a typical shank adapter because a split flushing element is intended to be used for connection with the shank adapter.

[0060] 4 and 5, it is further disclosed that the shank adapter 8 can include a narrow portion having a diameter D5 that is smaller than the diameters D1-D4.

[0061] 6 and 7 show a sleeve-like frame 18 of a flushing element 19, comprising a first half 19a and a second half 19b that can be bolted together. A joint or mating surface 35 exists between the halves 19a and 19b. The halves 19a and 19b together define an axial opening 53 within which a shank adapter can be installed. A sealing groove 36 for receiving a seal facing the shank adapter exists on the inner surface of the frame 18. A plurality of sealing grooves 37 for receiving a seal facing the body of the flushing housing exists on the outer surface of the frame 18. The number of sealing grooves 36, 37 can be selected according to requirements. Furthermore, a leak channel 38 can exist between two consecutive sealing elements.

[0062] FIG. 8 shows a front end FE of a rock drill with a flushing housing 13 equipped with a retractable cover element 39. In this solution, the flushing element 19 is a split flushing housing 19 with a cover element 39 that can be installed and removed from the base structure 40 or frame of the flushing housing 13. When the structure is opened by removing the cover element 39, the shank adapter 8, the seal S, and the bearing element 20 can be easily removed and installed laterally. The cover element 39 can be bolted to the base structure 40. The seal S and the bearing element 20 have a split structure to facilitate installation. Furthermore, a support element 41 has a split structure to function as a retracting aid. Flushing fluid can be supplied to the flushing space 21, which can be located on the cover element 39, through a supply port 42. Furthermore, a lubrication channel 43 can ensure proper lubrication of the bearing element 20.

[0063] 9 discloses a sealing ring S with one mold cut 44. The cut 44 or split line allows the sealing ring S to have a split structure. The split sealing ring S has two ends, which allows the split sealing ring S to be pressed head-first around the shank adapter toward the sealing groove.

[0064] 10 discloses a sealing ring S with multiple cutouts 44. In this case, the sealing ring S is made up of multiple pieces Sa-Sd that can be assembled around the shank adapter in the field. The number of pieces can be two, but in some cases can be three or even four. In FIGS. 9 and 10, the cutouts 44 are V-shaped.

[0065] Figure 11 discloses a sealing ring S in which the direction of the cuts 44 is different from the cuts shown in Figures 9 and 10. Figures 9 and 10 show axially oriented cuts or parting lines 44, whereas in Figure 11 the cuts or parting lines 44 are radial.

[0066] 12 discloses a bearing element 20 having a split configuration, with two bearing components 20a, 20b and a mating surface 45 between the two bearing components 20a, 20b. The bearing element 20 may have an elongated bearing portion 46 made of a sliding bearing material and may further have a lateral flange 47 at one end.

[0067] The drawings and the associated description are intended only to illustrate the concept of the invention. The invention may vary in detail within the scope of the claims.

Claims

1. A flushing element (19) for a rock drill (6), comprising: The flushing element (19) is configured to surround the shank adapter (8) passing through the flushing element (19); The flushing element (19) a supply opening (49) for supplying flushing liquid to a flushing space (21) surrounding the shank adapter (8); at least two sealing housings (51) for receiving flushing sealings (S, S2, S3), located at a certain axial distance from each other on both sides of the flushing space (21); Equipped with the flushing element (19) has a split configuration, whereby the flushing element (19) comprises two halves (19a, 19b) that can be placed on each other transversely to the axial direction of the shank adapter (8); The flushing element (19) has two halves (19a, 19b) that together define an axial opening (53), and the shank adapter (8) is installable within the axial opening (53).

2. said flushing element (19) being an elongated split bushing comprising two halves (19a, 19b) with longitudinal mating surfaces (35); 2. The flushing element according to claim 1, wherein the inner surface side of the opening is equipped with the sealing housing (51).

3. 2. The flushing element of claim 1, wherein the flushing element (19) is a split flushing housing (13) comprising a cover element (39) and a basic structure (40), whereby the cover element (39) is installable and detachable from the basic structure (40) of the flushing housing (13).

4. A rock drill (6), A body (12); an impact device (9) for generating an impact pulse (IP); a shank adapter (8) for receiving the impact pulse (IP) and transmitting the impact pulse (IP) as a stress wave to a drilling tool (7) connectable to the shank adapter (8); a rotation device (10) for rotating the shank adapter (8) about its longitudinal axis; a flushing head (13) at the forward end of said body (12); Equipped with the flushing head (13) comprises a flushing element (19) surrounding the shank adapter (8) and configured to form an annular flushing space (21) for supplying flushing liquid through the shank adapter (8) to the drilling tool (7); said flushing element (19) being a split structure comprising at least two matching components (19a, 19b, 39, 40); A rock drill (6), wherein the flushing element (19) is as claimed in any one of claims 1 to 3.

5. 5. The rock drill according to claim 4, wherein the flushing sealing (S, S1-S3) is a split seal (S) having at least one split line (44) so ​​that the split seal (S) can be fitted laterally around the shank adapter (8).

6. The shank adapter (8) a connecting head (25) for connecting said drilling tool (7); a rotating portion (26) located at an end portion of the shank adapter (8) opposite to the connecting head (25), the rotating portion (26) being provided with a plurality of splines (28) for transmitting torque; a flushing part (22) located between the connecting head (25) and the rotating part (26), the flushing part (22) being provided with a lateral flushing opening (23) contacting an axial passage (50) extending at its end on the connecting head side to the distal end of the shank adapter (8); Equipped with 6. A rock drill according to claim 4 or 5, wherein the outer diameters (D1, D4) of the connecting head (25) and the rotating part (26) are larger than the outer diameter (D3) of the flushing part (22).

7. 7. A rock drill according to claim 6, wherein the connecting head (25) of the shank adapter (8) comprises a shoulder (27) equipped with an axial contact surface (31) and a protruding axial section equipped with a connecting thread (30).

8. 8. A rock drill according to any one of claims 4 to 7, wherein the shank adapter (8) is supported axially movably by at least one split sliding bearing element (20).

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