Abstract
A shank adapter, rock drilling machine and method of mounting a shank adapter of a rock drilling machine inside a slide bearing element. The shank adapter includes a coupling head and a rotation portion at its opposite ends, and a flushing portion located therebetween. Outer diameters of the coupling head and the rotation portion are both greater than outer diameters of portions of the shank adaptor located therebetween.
Claims
1. A shank adapter of a rock drilling machine comprising: a coupling head arranged for connecting a drilling tool; a rotation portion located at an opposite end portion of the shank adapter relative to the coupling head, the rotation portion including several splines for transmitting torque; and a flushing portion located between the coupling head and the rotation portion, the flushing portion including a transverse flushing opening in contact with an axial flushing portion extending to a distal end of the shank adapter at the coupling head side end, wherein outer diameters of the coupling head and the rotation portion are both greater than outer diameters of the shank adapter located between the coupling head and the rotation portion.
2. The shank adapter as claimed in claim 1, further comprising a flushing portion and a bearing portion disposed between the coupling head and the rotation portion, and the outer diameters of the coupling head and the rotation portion both being greater than outer diameters of the flushing portion and the bearing portion.
3. The shank adapter as claimed in claim 1, the wherein a smallest diameter of the two outer diameters of the coupling head and the rotation portion is at least 5% greater than the greatest outer diameter between the coupling head and the rotation portion.
4. The shank adapter as claimed in claim 1, wherein a smallest diameter of the two outer diameters of the coupling head and the rotation portion is at least 4 mm greater than the greatest outer diameter between the coupling head and the rotation portion.
5. The shank adapter as claimed in claim 1, wherein the coupling head includes a shoulder provided with an axial contact surface and a protruding axial part provided with a coupling thread, and wherein an outer diameter of the shoulder is greater than the diameter of the coupling head.
6. A rock drilling machine, comprising: a body; an impact device arranged for generating impact pulses; a shank adapter arranged for receiving the impact pulses and transmitting the impact pulses as stress waves to a drilling tool connectable to the shank adapter; a rotation device arranged for turning the shank adapter around a longitudinal axis; at least one bearing element arranged for supporting the shank adapter; a flushing head at a front end of the body, wherein the flushing head includes a flushing element surrounding the shank adapter and configured to form an annular flushing space for feeding flushing agent through the shank adapter to the drilling tool, wherein the bearing element and the flushing element both have split structures including at least two compatible components, and wherein the shank adapter is in accordance with claim 1.
7. A method of mounting a shank adapter of a rock drilling machine inside a slide bearing element, the method comprising: implementing a split bearing element including at least two connectable bearing components; and connecting the shank adapter and the split bearing element together by means of transverse relative movement between the shank adapter and the bearing components.
8. The method as claimed in claim 7, further comprising pre-assembling the bearing element around the shank adapter and mounting the combination of the shank adapter and the bearing element in one piece inside the rock drilling machine.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0035] Some embodiments are described in more detail in the accompanying drawings, in which
[0036] FIG. 1 is a schematic side view of a rock drilling rig for surface drilling,
[0037] FIG. 2 is a schematic view of a hydraulic rock drilling machine,
[0038] FIG. 3 is a schematic and cross-sectional side view of front part of a rock drilling machine,
[0039] FIG. 4 is a schematic side view of a shank adapter provided with a coupling head implementing shoulder contact with a drilling tool,
[0040] FIG. 5 is a schematic side view of a shank adapter provided with a coupling head comprising a large dimensioned screw surface,
[0041] FIG. 6 is a schematic view of a flushing element comprising sleeve-like body with two halves,
[0042] FIG. 7 is a schematic and cross sectional view of the flushing element shown in FIG. 6,
[0043] FIG. 8 is a schematic and partly cross sectional side view of a flushing head having a split structure, and
[0044] FIG. 9 is a schematic view of a split bearing element seen in axial direction and comprising two halves.
[0045] For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner.
[0046] In the figures, like reference numerals identify like elements.
DETAILED DESCRIPTION OF SOME EMBODIMENTS
[0047] FIG. 1 shows a rock drilling rig 1 intended for surface drilling. The rock drilling rig 1 comprises a movable carrier 2 and at least one drilling boom 3 connected to the carrier 2. At a distal end portion of the drilling boom 3 is a drilling unit 4 provided with a feed beam 5 and a rock drilling machine 6 supported on it. A drilling tool 7 is connectable to the drilling machine 6. The rock drilling machine 6 comprises a shank adaptor 8 at a front end FE of the rock drilling machine 6 for connecting the tool 7. The rock drilling machine 6 further comprises an impact device 9 and a rotating device 10. The rock drilling machine 6 may be moved towards a drilling direction A on the feed beam 5 by means of a feed device 11. During the drilling impact pulses are generated by means of the impact device to the rotating shank adapter 8 which transmits the impacts pulses and torque to the drilling tool 7. Flushing agent flow is conveyed through a hollow structure to the shank adapter 8 and all the way through the drilling tool 7 to a bottom of the drilled hole for flushing drilling cuttings away from the drilled hole.
[0048] FIG. 2 discloses a rock drilling machine 6 comprising a body 12, an impact device 9, a rotating device 10 and a gear housing. Mounted at a front end FE of the body 12 are a flushing housing 13 and a shank adaptor 8. Flushing agent, such as water, is conveyed by means of a flushing channel 14 to the flushing housing 13 or flushing head.
[0049] The impact device 9 may comprise an impact piston 48 (shown in FIG. 4) for generating impact pulses IP to the shank adapter 8 in an impact direction. The rotation device 10 and transmission means inside a gear housing make the shank adapter 8 to rotate R around its longitudinal axis as it is shown FIG. 4.
[0050] FIG. 3 discloses a front end FE of a rock drilling machine in a highly simplified manner. A flushing housing 13 is provided with a pre-assembled shank module 15 comprising a shank adapter 8 and a flushing element 16 assembled around it. The flushing housing 13 may comprise a space inside which the module 15 can be pushed in axial installation direction ID and can be locked in place by means of a flange 17, for example. As can be seen, opposite ends of the shank adapter 8 have greater diameters D1 and D4 compared to diameters D2 and D3 between them. Therefore, the shank adapter 8 cannot be mounted in axial direction inside a frame 18 of a flushing element 19. Instead, the frame 18 has split structure and it comprises two halves mountable to each other in transverse direction. In addition to the frame 18, also sealings S1, S2 and S3, as well as a front bearing element 20 have split configuration. Thus, in the shown structure, the flushing element 19 comprises a split frame, split sealings and split bearings. The frame 18 and seals S2, S3 define together a flushing space 21 around a flushing portion 22 of the shank adapter 8. Flushing agent is fed via a feed opening 49 to a flushing space 21 surrounding the shank adaptor 8 and further through a flushing opening 23 of the shank adapter 8 to an axial passage 50 inside the shank adapter 8 wherein it flows towards a drilling tool.
[0051] On an inner surface of the flushing element 19 are at least two sealing housings 51 for receiving flushing sealings S2, S3. The sealing housings 51 are located at axial distance from each other and on opposite sides relative to the flushing space 21. There is also a sealing housing 52 for receiving a front sealing S1. The sealing housings 51, 52 may be sealing grooves or other suitable spaces.
[0052] In the disclosed solution diameter D2 of a bearing portion 24 may be minor than diameter D1 of a coupling head 25 of the shank adapter 8 and minor than diameter D4 of a rotation portion 26. This is advantageous for the propagation of the stress waves caused by impact pulses of the impact device. At the coupling head 25, or coupling portion, a shoulder 27 may form the greatest diameter D1. At the rotation portion 26 there may be several splines 28 which are designed to be in contact with a rotating gear of a gearing housing. Greater dimension D1 at the coupling head 25 may be advantageous regarding durability of the coupling and greater dimension D4 at the rotation portion 26 may be advantageous regarding transmission of torque.
[0053] The pre-assembled shank module 15 disclosed in FIG. 3 may be supported to the flushing housing 13 also in several alternative ways. For example, it is possible to mount the module 15 in a direction opposite to the disclosed installation direction ID. A further possibility is to design a flushing housing with an openable cover or with a split structure, whereby the module can be installed in one piece in transverse direction.
[0054] FIG. 3 further discloses that the shank adapter 8 may comprise surfaces 29 intended for retracting the shank adapter 8 and the connected drilling tool backwards by means of a feed device of a drilling unit when the drilling is completed.
[0055] FIG. 4 discloses a shank adapter 8 wherein a coupling head 25 comprises a shoulder 27 and a connecting thread 30. The shoulder 27 comprises an axial surface 31 for transmitting impact waves. Between a distal end 32 of the shank adapter 8 and a drilling tool 7 is a clearance. Diameters D1 and D4 are greater than diameters D2 and D3 between them. Diameter of a front bearing of a piston 33 and diameter D3 may be substantially equal. At a rear end of the shank adapter 8 may be a portion for receiving impact pulses and provided with an impact surface 34. Diameter D5 of the impact portion may also be equal or substantially equal to the diameter DP of the percussion piston 33. An advantage of this is that then the stress waves propagate well through the shank adapter 8.
[0056] FIG. 4 discloses a so called shoulder contact shank adapter 8, whereas FIG. 5 discloses a so called bottom contact shank adapter 8. In FIG. 5 a distal end 32 of the shank adapter 8 is tightened by means of a thread 30 against a drill tool 7. Diameter D1 of the thread 30 can be dimensioned greater than in typical shank adapters because a split flushing element is intended to be used in connection with it.
[0057] In FIGS. 4 and 5 there is further disclosed that the shank adapter 8 may comprise a thinned portion having a diameter D5 which is minor than diameters D1-D4.
[0058] There may also be a thinned portion at the flushing opening 23.
[0059] FIGS. 6 and 7 disclose a sleeve-like frame 18 of a flushing element 19 comprising a first halve 19a and second halve 19b, which can be bolted together. Between the halves 19a, 19b are joint surfaces or mating surfaces 35. The mating surfaces 35 may be flat or they may be provided with shaped sealing profiles. Further, between the mating surfaces 35 may or may not be a gasket, sealing material or sealing mass. The halves 19a, 19b may be bolted together or may be connected to each other in any other ways, such as by means of shape locking, for example. The halves 19a, 19b define together an axial opening 53 inside which a shank adapter is mountable. On an inner surface of the frame 18 are sealing grooves 36 for receiving sealings facing towards a shank adapter. On an outer surface of the frame 18 are several sealing grooves 37 for receiving sealings facing towards a body of a flushing housing. Number of sealings and sealing grooves 36, 37 may be selected according to the need. Further, there may be leakage channels 38 between two successive sealing elements.
[0060] FIG. 8 discloses a front end FE of a rock drilling machine comprising a flushing housing 13 provided with an openable cover element 39. In this solution there is a flushing element 19 which is a split flushing housing 19 comprising the cover element 39 which is mountable and demountable to a basic structure 40 or frame of the flushing housing 13. It is easy to dismount and mount the shank adapter 8, seals S and a bearing element 20 in transverse direction when the structure is opened by removing the cover element 39. The cover element 39 may be bolted to the basic structure 40. The seals S and the bearing element 20 have split structures to facilitate their mounting. Also, a support element 41 for serving as retracting aid has a split structure. Flushing agent can be fed through a feed port 42 to a flushing space 21 which may be located on the cover element 39. Further, a lubricating channel 43 may provide the bearing element 20 with proper lubrication.
[0061] FIG. 9 discloses a bearing element 20 having a split configuration and comprising two bearing components 20a, 20b and mating surfaces 45 between them. The bearing element 20 may comprise an elongated bearing portion 46 made of slide bearing material, and further a transverse flange 47 at its one end.
[0062] The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.
