Rotary sleeve, rock drilling machine and method

Abstract

A rotating sleeve (17), a rock drilling rig (6) and a method of manufacturing a rotating sleeve. The invention relates to a rotary sleeve mountable around a shank adapter (8) of a rock drilling machine and comprising a number of internal teeth (22) provided with opposing first (32) and second (33) tooth side surfaces for transmitting rotation to the shank adapter. The internal tooth is provided with an end decompression portion (38, 39) comprising a diagonal plane between a tooth side surface and an end surface (34) of the tooth.

Description

Technical Field

[0001] The present invention relates to a rotary sleeve of a rock drill. The rotary sleeve can be mounted around a drill shank adapter and is intended to transmit rotational torque between a rotary device and the drill shank adapter.

[0002] The present invention further relates to a rock drill and a method of manufacturing a rotary sleeve of a rock drill. Background Art

[0003] The field of the present invention is more specifically defined in the preamble of the independent claims.

[0004] In mines and other work sites, different types of rock drills are used. The rock drill is provided with one or more booms, and the rock drill is arranged at the distal end of the boom. The rock drill includes impact equipment provided with an impact piston configured to provide an impact pulse to a drill tool via a drill shank adapter. The drill shank adapter is configured to transfer the impact pulse and torque from the rock drill to the drill tool. Surrounding the drill shank adapter is a rotary sleeve rotated by a rotary device. The rotary sleeve includes a number of internal teeth that match the teeth or splines of the drill shank adapter. These internal teeth are subjected to high stresses during rotation. In known configurations, some drawbacks have been detected in the rotary sleeve, particularly with regard to the durability of its internal teeth. Summary of the Invention

[0005] The object of the present invention is to provide a novel and improved rotary sleeve, a rock drill equipped with such a rotary sleeve, and a method of manufacturing a rotary sleeve of a rock drill.

[0006] The rotary sleeve according to the present invention is characterized by the features of the characterizing part of the first independent apparatus claim.

[0007] The rock drill according to the present invention is characterized by the features of the characterizing part of the second independent apparatus claim.

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

[0009] One idea of the disclosed solution is a rotary sleeve that can be mounted around a drill shank adapter of a rock drill, the rotary sleeve including a number of internal teeth provided with opposing first and second tooth side surfaces for transferring rotation to the drill shank adapter. The internal teeth have end surfaces at longitudinal ends of the teeth. Further, the teeth are provided with at least a first end relief portion including a first bevel surface between the first tooth side surface and the end surface.

[0010] In other words, each internal tooth of the rotary sleeve is provided with one or more end relief portions, where the sharp edges between the tooth side surface and the end surface are chamfered or rounded. The tooth may have the end relief portion at one end or both ends.

[0011] The advantage of the disclosed solution is that, due to the end relief portions, the load directed to the end portions of the teeth can be reduced. This can avoid material fracture at the end portions of the internal teeth and can improve the durability of the rotary sleeve. Thus, the maintenance intervals can be longer, ensuring an effective drilling process. In addition, when the risk of fracture at the tooth ends can be addressed, this solution allows the use of a greater torque.

[0012] According to one embodiment, the internal teeth are straight teeth, i.e., the teeth are straight. The internal teeth having a straight and elongated configuration are easy to manufacture, and during use, the internal teeth allow axial movement between the rotary sleeve and the drill shank adapter.

[0013] According to one embodiment, alternatively, the internal teeth are helical or twisted teeth, i.e., the teeth are not straight.

[0014] According to one embodiment, the length of the rotary sleeve is greater than the diameter of the rotary sleeve, whereby the teeth are relatively long in the axial direction.

[0015] According to one embodiment, the length of the rotary sleeve is a multiple of the diameter of the rotary sleeve.

[0016] According to one embodiment, the first tooth side surface is configured to transmit rotation when the drill shank rotates in the drilling direction, and the second tooth side surface is configured to transmit rotation when the drill shank rotates in the opposite direction.

[0017] According to one embodiment, the end relief portion has a flat surface. In other words, the chamfered surface between the first tooth side surface and the end surface is planar. Thus, the chamfered surface has as simple a surface shape as possible for manufacturing.

[0018] According to one embodiment, the end relief portion has an alternately curved surface. In other words, the sharp edge between the first tooth side surface and the end surface is rounded.

[0019] According to one embodiment, the tooth is provided with a second end relief portion, which includes a second chamfered surface between the second tooth side surface and the end surface. In other words, all four sharp corners of the tooth are chamfered, providing four end relief portions for the tooth. The advantage of this embodiment is that the tooth ends are also protected from loads in the reverse rotation direction.

[0020] According to one embodiment, the teeth are provided with end reliefs only at one end of the teeth. In other words, the corners of each tooth are chamfered at the front end or the rear end of each tooth. The end relief may be formed at, for example, the end that bears a greater load. In another embodiment, the teeth are provided with a first end relief or a second end relief only at one end of the teeth. All different combinations of placing the end reliefs are possible.

[0021] According to one embodiment, the rotating sleeve includes a first sleeve member on the inner side and a second sleeve member on the outer side that can be arranged within each other, and wherein the first sleeve on the inner side includes the internal teeth provided with the end reliefs. In other words, the rotating sleeve has a two-piece construction, wherein the rotational torque is transmitted on the outer surface of the second sleeve member on the outer side, and wherein a gear system is provided between the first sleeve member on the inner side and the second sleeve member on the outer side, and the gear system is used to transmit torque between the sleeve members.

[0022] According to one embodiment, the first sleeve member on the inner side is a replaceable wear part.

[0023] According to one embodiment, the first sleeve member on the inner side is made of bronze or a corresponding sliding bearing material.

[0024] According to an alternative embodiment, the rotating sleeve has a one-piece construction. Thus, the rotating sleeve includes internal teeth with the end reliefs and external teeth for receiving torque from a rotating device.

[0025] According to one embodiment, the rotating sleeve has external teeth for receiving torque directly (integral structure) or indirectly (via the second sleeve member on the outer side) from the rotating device.

[0026] According to one embodiment, at least the first tooth side surface includes lubrication grooves. In other words, each first tooth side surface has an axial lubrication groove for providing lubricant to the contact surface between the splines of the drill shank adapter and the first tooth side surface of the rotating sleeve.

[0027] According to one embodiment, both the depth and width of the lubrication grooves are at least 2 mm.

[0028] According to one embodiment, the depth of the lubrication grooves is 2 - 4 mm.

[0029] According to one embodiment, both ends of the lubrication groove open towards the end relief portion. In other words, the lubrication groove does not have closed ends, but rather the ends extend to the teeth. In a structure where the lubrication groove extends over the entire length of the internal teeth, the end relief portion well protects the high-load areas around the lubrication groove at the end portions of the teeth.

[0030] According to one embodiment, the length of the end relief portion is 8 - 14% of the total length of the internal teeth.

[0031] According to one embodiment, the lateral dimension of the end relief portion is 10 - 16% of the distance between two opposite parallel tooth side surfaces.

[0032] According to one embodiment, the angle between the surface of the end relief portion and the longitudinal axis of the internal teeth is 9 - 16°.

[0033] According to one embodiment, the shape of the end relief portion corresponds to a truncated triangle.

[0034] According to one embodiment, the end relief portion is formed by a wire cutting method based on electrical discharge machining (EDM). In other words, the end relief portion is manufactured by wire cutting EDM or spark machining technology.

[0035] According to an alternative solution, the end relief portion is formed by a chip removal milling cutter.

[0036] According to one embodiment, the disclosed solution relates to a rock drill, comprising: a main body; an impact device for generating impact pulses; a drill shank adapter for receiving the impact pulses and transmitting the impact pulses as stress waves to a drill tool that can be connected to the drill shank adapter; a rotation device for rotating the drill shank adapter about its longitudinal axis; and a rotating sleeve surrounding the drill shank adapter and transmitting torque from the rotation device to the drill shank adapter. Furthermore, the rotating sleeve is the rotating sleeve according to any one of the features and embodiments disclosed in this document.

[0037] According to one embodiment, the disclosed solution relates to a method of manufacturing a rotary sleeve of a rock drill, wherein the rotary sleeve is capable of being mounted around a drill shank adapter and is adapted to transmit torque between the rotary device and the drill shank adapter. The method includes: providing a plurality of internal teeth on the rotary sleeve, wherein the internal teeth include a first tooth side surface and a second tooth side surface; and providing end surfaces at longitudinal ends of the teeth. The method further includes chamfering an edge between the first tooth side surface and the end surface of the tooth to provide an end relief for the tooth. The end relief protects the tooth end from breakage caused by excessive loads.

[0038] The above-disclosed embodiments can be combined to form a suitable solution having the desired features among the above features. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Some embodiments are described in more detail in the drawings, in which

[0040] Figure 1 is a schematic side view of a rock drill for surface drilling,

[0041] Figure 2 is a schematic view of a hydraulic rock drill,

[0042] Figure 3 is a schematic cross-sectional side view of the front part of a rock drill,

[0043] Figure 4 is a schematic side view of a drill shank adapter provided with splines at its rear end for receiving rotational torque,

[0044] Figure 5 is a schematic view of a rotary sleeve in which a splined drill shank adapter can be arranged inside,

[0045] Figure 6 is a schematic view of the internal teeth of the rotary sleeve as viewed in the axial direction of the rotary sleeve,

[0046] Figure 7 is Figure 5 an axial schematic view of the rotary sleeve shown,

[0047] Figure 8 is Figure 5 and Figure 7 a schematic cross-sectional side view of the rotary sleeve shown,

[0048] Figure 9 is a schematic view of a rotary sleeve with internal teeth having a milled end relief,

[0049] Figure 10 Schematic view of the milled internal teeth of a rotary sleeve as viewed in the axial direction of the rotary sleeve

[0050] Figure 11 -Not covered by the subject matter of the claims- Schematic view of a rotary sleeve with internal teeth but without lubrication grooves

[0051] Figure 12 -Not covered by the subject matter of the claims- Schematic view of a rotary sleeve with an end relief section only at the rear end of the internal teeth of the sleeve, and

[0052] Figure 13 Schematic view of a rotary sleeve with end relief sections provided at both ends of the internal teeth of the sleeve

[0053] For clarity, the drawings illustrate some embodiments of the disclosed solution in a simplified manner. In the drawings, the same reference numerals denote the same elements Detailed Description

[0054] Figure 1 Shows a rock drill 1 intended for surface drilling. The rock drill 1 includes a movable carrier 2 and at least one boom 3 connected to the carrier 2. A drilling unit 4 is at the distal end of the boom 3, which is provided with a feed beam 5 and a rock drill 6 supported on the feed beam 5. A drill string 7 can be connected to the rock drill 6. The rock drill 6 includes a drill shank adapter 8 at the front end FE of the rock drill 6 for connecting the tool 7. The rock drill 6 further includes an impact device 9 and a rotation device 10. The rock drill 6 can be moved on the feed beam 5 towards the drilling direction A by means of a feed device 11. During drilling, an impact pulse is generated by the impact device to the rotating drill shank adapter 8, which transfers the impact pulse and torque to the drill string 7. A flushing agent flow is conveyed through a hollow structure to the drill shank adapter 8 and all the way through the drill string 7 to the bottom of the borehole to flush the drill cuttings out of the borehole

[0055] Figure 2 Discloses a rock drill 6, which includes a body 12, an impact device 9, a rotation device 10 and a gearbox G. A flushing housing 13 and a drill shank adapter 8 are mounted at the front end FE of the gearbox G. A flushing agent, such as water, is conveyed to the flushing housing 13 or the flushing head by means of a flushing channel 14

[0056] Figure 3The gearbox G of the rock drill 6 is disclosed. The impact surface 15 of the drill shank adapter 8 receives the impact pulse from the impact piston 16, and the rotational torque is transmitted to the drill shank adapter 8 by means of the rotary sleeve 17. The rotary sleeve 17 is rotated by a rotary device 10 which is connected to the rotary sleeve 17 by means of a gear 18. The rotary sleeve 17 can be a one-piece transmission element, or it can comprise Figure 3 the two components shown. The two-piece construction can comprise a first rotary sleeve component 17a on the inside and a second rotary sleeve component 17b on the outside, between which there is a gear 19. The rearmost end of the drill shank adapter 8 can be surrounded by means of a drill shank sleeve 20 for transmitting the axial force in the drilling direction A and for transmitting the axial force in the opposite direction for the drill shank adapter 8. The drill shank adapter 8 comprises splines 21 or corresponding teeth which come into contact with the internal teeth 22 of the rotary sleeve 17.

[0057] The flank surfaces of the internal teeth 22 can comprise lubrication grooves 23 for the gear contact between the rotary sleeve 17 and the drill shank adapter 8. The lubrication grooves 23 can be open at both ends, and lubricating oil can be guided into the grooves through lubrication channels 24. In Figure 3 the figure, the arrows show the flow of the lubricating medium and the different lubrication channels and routes. Some examples of the routes are marked by reference numerals 25, 26.

[0058] Figure 4 A drill shank adapter 8 is disclosed, wherein the connecting head 27 comprises a shoulder 28 and a connecting thread 29. An alternative connecting end arrangement can also be implemented. At the rear end 30 of the drill shank adapter 8 there can be a part for receiving the impact pulse IP and an impact surface 15 is provided. There are also splines 21 for transmitting the rotation R for the drill shank adapter 8. An opening 32 is provided at the intermediate section 31 for guiding the flushing fluid to the inside of the drill shank adapter and to the drill 7.

[0059] Figure 5 A rotary sleeve 17 is disclosed in which the drill shank adapter of the rock drill can be mounted. The rotary sleeve 17 comprises a number of internal teeth 22 which are provided with opposite first flank surfaces 32 and second flank surfaces 33 for transmitting the rotation to the drill shank adapter. The internal teeth 22 have end surfaces 34 at the longitudinal ends of the teeth. During normal drilling, the rotary sleeve 22 can be rotated in the direction R and rotated in the opposite direction by means of a rotary device. On the outer surface of the rotary sleeve 22 there are external teeth 35 for transmitting the rotational torque to the rotary sleeve 22. The external teeth 22 can form a gear 19 as shown previously Figure 3 in the figure. The external teeth 35 can be located at the front end 36 of the rotary sleeve 17, and the rear end 37 can be free of gears.

[0060] Figure 5 Further shown, an end relief portion 38, 39 is provided between the end surface 34 and the tooth side surfaces 32, 33 of the internal tooth 22. Figure 6 One internal tooth 22 of the rotary sleeve is shown in detail, Figure 7 the same rotary sleeve 17 is shown in different viewing directions, and Figure 8 is a cross-sectional view of the same structure.

[0061] Figures 5 - 8 Shown, the first tooth side surface 32 of the internal tooth 22 includes a lubrication groove 23. The lubrication groove 23 can extend to the internal tooth at the end. Thus, both ends of the lubrication groove are open to the first end relief portions 38, 39. There may be a lubrication passage or groove 40 on the front surface for guiding the lubricating fluid.

[0062] Figure 5 It is further disclosed that the angle K between the surface of the end relief portions 38, 39 and the longitudinal axis of the internal tooth 22 is 9 - 16°.

[0063] Figure 7 The rotary sleeve 17 is shown axially and is observed from its end direction. Figure 7 and cross-section Figure 8 both show that there are also end relief portions 38, 39 at the rear end of the internal tooth 22.

[0064] Figure 5 , Figure 7 , Figure 8 , Figure 9 and Figures 11 - 13 The rotary sleeve disclosed in Figure 3 can be the inner rotary sleeve member 17a shown in Figure 7 , and the outer rotary sleeve member can be arranged around the inner rotary sleeve member 17a. In other words, the rotary sleeve arrangement can include a first sleeve member on the inner side and a second sleeve member on the outer side that can be arranged within each other. In Figure 7 , the reference numeral 41 represents the surrounding outer second sleeve member by a dashed line. The first sleeve on the inner side includes internal teeth provided with end relief portions, and teeth or other transmission elements are located between the sleeve members for transmitting torque between the sleeve members. In another possible embodiment, the rotational torque is directly transmitted on an integral rotary sleeve that includes internal teeth and external teeth and end relief portions located on the internal teeth.

[0065] Figure 9 and Figure 10It is shown that the inner teeth 22 of the rotating sleeve 17 are provided only with a first end relief portion 38. Thus, in this rotating sleeve 17, only the ends of the inner teeth 22 are protected against high loads in the normal rotation direction R. In addition, only the first tooth flank surface 32 of the inner teeth is provided with lubrication grooves 23. In the reverse rotation direction, the load is small, so it is not necessarily required to provide an end relief portion and lubrication grooves on the opposite second tooth flank surface 33.

[0066] Figure 9 and Figure 10 The end relief portion 38 of the inner teeth 22 shown is produced by milling technology, so some additional marks 42 generated by the chip removal tool can be seen on the inner surface of the rotating sleeve 17. When the end relief portions 38, 39 are manufactured by wire cutting based on electrical discharge machining, there are no such marks, which is obvious when inspecting Figures 5 - 8 during inspection.

[0067] Figure 11 -Not covered by the subject matter of the claims- discloses a rotating sleeve 17, which is different from the previously shown rotating sleeve in that there are no lubrication grooves on the tooth flank surfaces 32, 33 of the inner teeth 22. The inner teeth 22 are provided with end relief portions 38, 39 at both ends thereof.

[0068] Figure 12 -Not covered by the subject matter of the claims- discloses a rotating sleeve 17, which includes end relief portions 38, 39 only at the rear ends of the inner teeth 22. In addition, there are no lubrication grooves on the tooth flank surfaces 32, 33 of the inner teeth.

[0069] Figure 13 Discloses features similar to the previous Figure 5 ones, but more clearly shows that the ends of the inner teeth 22 can be provided with end relief portions 38, 39.

[0070] The drawings and the related description are only intended to illustrate the idea of the present invention. In terms of the details of the present invention, the present invention can vary within the scope of the claims.

Claims

1. A rotary sleeve (17) capable of being mounted around a drill shank adapter (8) of a rock drill (6), And wherein, wherein the rotary sleeve (17) includes a plurality of internal teeth (22), and the internal teeth are provided with opposite first tooth side surfaces (32) and second tooth side surfaces (33) for transmitting rotation to the drill shank adapter (8); and, the internal teeth (22) have end surfaces (34) at longitudinal ends of the internal teeth (22); characterized in that the internal teeth (22) are provided with at least a first end relief portion (38), and the first end relief portion (38) includes a first bevel surface between the first tooth side surface (32) and the end surface (34); at least the first tooth side surface (32) includes lubrication grooves (23); and both ends of the lubrication grooves (23) open towards the end relief portions (38, 39).

2. The rotary sleeve according to claim 1, characterized in that the internal teeth (22) are provided with a second end relief portion (39), and the second end relief portion includes a second bevel surface between the second tooth side surface (33) and the end surface (34).

3. The rotary sleeve according to claim 1 or 2, characterized in that the rotary sleeve (17) includes a first sleeve member (17a) on the inner side and a second sleeve member (17b) on the outer side that can be arranged within each other, and wherein the first sleeve member (17a) on the inner side includes the internal teeth (22) provided with the end relief portions (38, 39).

4. The rotary sleeve according to any one of the preceding claims 1 - 3, characterized in that: the angle (K) between the surface of the end relief portions (38, 39) and the longitudinal axis of the internal teeth (22) is 9 - 16°.

5. The rotary sleeve according to any one of the preceding claims 1 - 4, characterized in that: the end relief portions (38, 39) are formed by a wire electrical discharge machining-based wire cutting method.

6. A rock drill (6), comprising: a main body (12); an impact device (9) for generating an impact pulse (IP); a drill shank adapter (8) for receiving the impact pulse (IP) and transmitting the impact pulse (IP) as a stress wave to a drill tool (7) that can be connected to the drill shank adapter (8); a rotary device (10) for rotating the drill shank adapter (8) about its longitudinal axis; and a rotary sleeve (17) surrounding the drill shank adapter (8) and transmitting torque from the rotary device (10) to the drill shank connector (8); characterized in that the rotary sleeve (17) is the rotary sleeve according to any one of the preceding claims 1 - 5.

7. A method of manufacturing a rotary sleeve (17) of a rock drill (6), wherein, The rotary sleeve (7) can be mounted around the drill shank adapter (8) for transmitting torque between the rotary device (10) and the drill shank adapter (8); and the method includes: A number of internal teeth (22) are provided on the rotary sleeve (17), wherein the internal teeth (22) include a first tooth side surface (32) and a second tooth side surface (33); and End surfaces (34) are provided at the longitudinal ends of the teeth (22) of the internal teeth (22); It is characterized by including the following steps Chamfering the edge between the first tooth side surface (32) and the end surface (34) of the internal tooth (22) to provide an end pressure relief portion (38, 39) for the internal tooth (22); and Lubricating grooves (23) are provided on at least the first tooth side surface (32), wherein both ends of the lubricating groove (24) open to the end pressure relief portion (38, 39).

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