Rotating sleeve, rock drill and method

Abstract

A rotating sleeve (17), a rock drill (6), and a method for manufacturing the rotating sleeve. The rotating sleeve is mountable around a shank adapter (8) of the rock drill and includes several internal teeth (22) with opposing first and second flank surfaces (32, 33) for transmitting rotation to the shank adapter (8). The internal teeth are provided with end reliefs (38, 39) including chamfers between the flank surfaces and end faces (34) of the teeth.

Description

[Background technology]

[0001] The present invention relates to a rotating sleeve for a rock drill, which is mountable around a shank adapter and is intended to transmit rotational torque between a rotating device and the shank adapter.

[0002] The invention further relates to a rock drill and a method for manufacturing a rotating sleeve for a rock drill.

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

[0004] Different types of rock drilling rigs are used in mines and other work sites. The rock drilling rigs are provided with one or more booms, and a rock drill is located at the distal end of the boom. The rock drill includes an impact device with an impact piston configured to impart an impact pulse to the drilling tool via a shank adapter. The shank adapter is configured to transmit the impact pulse and torque from the rock drill to the drilling tool. Around the shank adapter is a rotating sleeve that is rotated by a rotating device. The rotating sleeve includes several internal teeth that match the teeth or splines of the shank adapter. The internal teeth are subjected to high stress during rotation. In known designs, several drawbacks have been identified in the rotating sleeve, particularly with regard to the durability of the internal teeth. Summary of the Invention

[0005] SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and improved rotating sleeve, a rock drill equipped with such a rotating sleeve, and a method for manufacturing a rotating sleeve for a rock drill.

[0006] The rotating sleeve according to the invention is characterized by the characterizing features of the first independent device claim.

[0007] The rock drill according to the invention is characterized by the characteristic features of the second independent equipment claim.

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

[0009] The disclosed solution concept is that a rotating sleeve, mountable around a shank adapter of a rock drill, includes several internal teeth with opposing first and second flank surfaces for transmitting rotation to the shank adapter. The internal teeth have end faces at their longitudinal ends. Furthermore, the teeth are provided with at least a first end relief including a first chamfer between the first flank surface and the end faces.

[0010] In other words, each internal tooth of the rotating sleeve is provided with one or more end reliefs, and the sharp edges between the flank and end faces are beveled or chamfered. The teeth can have end reliefs at one or both ends.

[0011] The advantage of the disclosed solution is that the end relief reduces the loads directed at the end portions of the teeth. In this way, material breakage at the end portions of the internal teeth can be avoided and the durability of the rotating sleeve can be improved. This increases the service intervals and ensures an efficient drilling process. Furthermore, this solution allows the use of higher torques if the risk of tooth end breakage can be eliminated.

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

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

[0014] According to one embodiment, the length of the rotating sleeve is greater than the diameter of the rotating sleeve, which results in the teeth being relatively long in the axial direction.

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

[0016] According to one embodiment, the above-mentioned first flank surface is configured to transmit rotation when the shank rotates in the drilling direction, and the above-mentioned second flank surface is configured to transmit rotation when the shank rotates in the opposite direction.

[0017] According to one embodiment, the end relief has a flat surface. In other words, the chamfer between the first flank and the end face is flat. The chamfer then has as simple a surface shape as possible.

[0018] According to one embodiment, the end relief has an alternatively curved surface, in other words the sharp edge between the first flank surface and the end face is rounded.

[0019] According to one embodiment, the tooth is provided with a second end relief, which includes a second chamfer between the second flank and the end face. In other words, all four sharp corners of the tooth are chamfered to provide four end reliefs for the tooth. The advantage of this embodiment is that the tooth ends are also protected from counter-rotational loads.

[0020] According to one embodiment, the teeth are provided with an end relief only at one end of the tooth. In other words, the corner of each tooth is chamfered either at the front end or at the rear end of each tooth. The end relief can be formed, for example, at the end that is subjected to the greater load. In a further embodiment, the teeth are provided with a first or second end relief only at one end of the tooth. Any combination of arrangements of the end reliefs is possible.

[0021] According to one embodiment, the rotating sleeve comprises an inner first sleeve component and an outer second sleeve component that can be arranged inside each other, the inner first sleeve component having internal teeth provided with end reliefs. In other words, the rotating sleeve has a two-part design in which the rotational torque is transmitted to the outer surface of the outer second sleeve component and a gear system is present between the inner first sleeve component and the outer second sleeve component for transmitting the torque between the sleeve components.

[0022] According to one embodiment, the inner first sleeve component is a replaceable wear component.

[0023] According to one embodiment, the inner first sleeve component is made of bronze or a corresponding plain bearing material.

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

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

[0026] According to one embodiment, at least the first flank surface is provided with a lubrication groove, i.e., each first flank surface has one axial lubrication groove for supplying lubricant to the contact surface between the spline of the shank adapter and the first flank surface of the rotating sleeve.

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

[0028] According to one embodiment, the lubrication groove has a depth of 2 to 4 mm.

[0029] According to one embodiment, both ends of the lubrication groove open into end reliefs. In other words, the lubrication groove has no closed ends and extends from end to end of the tooth. In configurations where the lubrication groove extends the entire length of the internal tooth, the end reliefs provide adequate protection from the high load areas surrounding the lubrication groove at the ends of the tooth.

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

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

[0032] According to one embodiment, the angle between the surface of the end relief and the longitudinal axis of the internal tooth is between 9 and 16 degrees.

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

[0034] According to one embodiment, the end relief is formed by a wire-cut method based on electrical discharge machining (EDM), in other words, the end relief is manufactured by wire EDM or spark machining techniques.

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

[0036] According to one embodiment, the disclosed solution relates to a rock drill comprising a body, an impact device for generating impact pulses, a shank adapter for receiving the impact pulses and transmitting them as stress waves to a drilling tool connectable to the shank adapter, a rotation device for rotating the shank adapter about its longitudinal axis, and a rotating sleeve surrounding the shank adapter and transmitting torque from the rotation device to the shank adapter, wherein the rotating sleeve further complies with any one of the features and embodiments disclosed herein.

[0037] According to one embodiment, the disclosed solution relates to a method for manufacturing a rotating sleeve for a rock drill, the rotating sleeve being mountable around a shank adapter for transmitting torque between a rotating device and the shank adapter. The method includes providing the rotating sleeve with several internal teeth, each having a first flank surface and a second flank surface, and providing end faces at longitudinal ends of the internal teeth. The method further includes chamfering edges between the first flank surface and the end faces of the internal teeth to provide end reliefs for the internal teeth. The end reliefs protect the internal tooth end profile from damage caused by excessive loads.

[0038] The above disclosed embodiments can be combined to form suitable solutions having the above characteristics required.

[0039] Some embodiments are explained in more detail in the accompanying drawings. [Brief explanation of the drawings]

[0040] [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 of a hydraulic rock drill. [Figure 3] FIG. 2 is a schematic cross-sectional side view of the front of the rock drill. [Figure 4] FIG. 1 is a schematic side view of a shank adapter having a splined rear end for receiving rotational torque. [Figure 5] 1 is a schematic diagram of a rotating sleeve into which a splined shank adapter can be placed. FIG. [Figure 6] 4 is a schematic view of the internal teeth of the rotating sleeve as viewed from the axial direction of the rotating sleeve. FIG. [Figure 7] FIG. 6 is a schematic axial view of the rotating sleeve shown in FIG. 5. [Figure 8] FIG. 8 is a schematic cross-sectional side view of the rotating sleeve shown in FIGS. 5 and 7. [Figure 9] FIG. 10 is a schematic diagram of a rotating sleeve with internal teeth having milled end reliefs. [Figure 10] 10 is a schematic view of the milled internal teeth of the rotating sleeve as viewed from the axial direction of the rotating sleeve. FIG. [Figure 11] 1 is a schematic diagram of a rotating sleeve with internal teeth without lubrication grooves, which is not covered by the subject matter of the claims. [Figure 12] 1 is a schematic diagram of a rotating sleeve provided with end relief only at the rear end of the internal teeth of the sleeve, which is not covered by the subject matter of the claims. [Figure 13] FIG. 10 is a schematic diagram of a rotating sleeve with end reliefs on both ends of the internal teeth of the sleeve. DETAILED DESCRIPTION OF THE INVENTION

[0041] For clarity, the drawings show some embodiments of the disclosed solution in a simplified manner, in which like reference numbers indicate like elements.

[0042] 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 movable carrier 2. The tip of the drilling boom 3 contains a drilling unit 4, which includes a feed beam 5 and a rock drill 6 supported thereon. A drilling tool 7 can be connected to the rock drill 6. The rock drill 6 has a shank adapter 8 at its front end FE for connecting the tool 7. The rock drill 6 further comprises an impact device 9 and a rotating device 10. The rock drill 6 can be moved in a drilling direction A on the feed beam 5 by a feed device 11. During drilling, the impact device generates an impact pulse to the rotating shank adapter 8, which transmits the impact pulse and torque to the drilling tool 7. A flow of flushing agent is directed through the hollow structure to the shank adapter 8 and through the drilling tool 7 to the bottom of the borehole, flushing cuttings from the borehole.

[0043] Figure 2 shows a rock drill 6 comprising a body 12, an impact device 9, a rotation device 10 and a gear housing G. A flushing housing 13 and a shank adapter 8 are attached to the front end FE of the gear housing G. A flushing agent such as water is conveyed to the flushing housing 13 or flushing head by a flushing channel 14.

[0044] FIG. 3 shows the gear housing G of the rock drill 6. The impact surface 15 of the shank adapter 8 receives an impact pulse from the striking piston 16, and the rotational torque is transmitted to the shank adapter 8 by the rotating sleeve 17. The rotating sleeve 17 is rotated by a rotating device 10 coupled to the rotating sleeve 17 by a gear 18. The rotating sleeve 17 may be a single-piece transmission element or may have two components, as shown in FIG. 3. The two-piece configuration may include an inner first rotating sleeve component 17a and an outer second rotating sleeve component 17b, with a gear 19 between them. The rear end of the shank adapter 8 is surrounded by a shank sleeve 20, which can transmit axial forces in the drilling direction A and the opposite direction of the shank adapter 8. The shank adapter 8 has splines 21 or corresponding teeth that contact the internal teeth 22 of the rotating sleeve 17.

[0045] The flanks of the internal teeth 22 may include lubrication grooves 23 for gear contact between the rotating sleeve 17 and the shank adapter 8. The lubrication grooves 23 may be open at both ends, and lubricant may be introduced into the grooves through lubrication channels 24. In Figure 3, the flow of the lubricating medium is indicated by arrows and the different lubrication channels and paths. Some examples of paths are indicated by reference numerals 25 and 26.

[0046] 4 discloses a shank adapter 8 in which the coupling head 27 includes a shoulder 28 and connecting threads 29. Alternative coupling end configurations may be implemented. The rear end 30 of the shank adapter 8 may include a portion for receiving the impact pulse IP and may be provided with an impact surface 15. There is also a spline 21 for transmitting the rotation R of the shank adapter 8. The middle portion 31 includes an opening 32 for directing flushing fluid within the shank adapter to the drilling tool 7.

[0047] FIG. 5 shows a rotating sleeve 17 into which a rock drill shank adapter can be attached. The rotating sleeve 17 has several internal teeth 22 with opposing first and second flanks 32 and 33 to transmit rotation to the shank adapter. The internal teeth 22 have end faces 34 at their longitudinal ends. The rotating sleeve 22 can be rotated by a rotating device in the R direction during normal drilling and in the reverse direction. The outer surface of the rotating sleeve 22 has external teeth 35 for transmitting rotational torque to the rotating sleeve 22. The external teeth 22 can form the gear 19 shown in FIG. 3 above. The external teeth 35 can be located at the front end 36 of the rotating sleeve 17, while the rear end 37 can be gearless.

[0048] Figure 5 further shows that the internal toothing 22 is provided with end reliefs 38, 39 between the end face 34 and the flank faces 32, 33. Figure 6 shows one internal toothing 22 of the rotating sleeve in detail, Figure 7 shows the same rotating sleeve 17 in a different view direction, and Figure 8 is a cross-sectional view of the same structure.

[0049] 5-8 show that the first flank surface 32 of the internal tooth 22 is provided with a lubrication groove 23. The lubrication groove 23 can extend from end to end of the internal tooth, whereby both ends of the lubrication groove open into first end reliefs 38, 39. The front surface may also have lubrication channels or grooves 40 for conducting lubricating fluid.

[0050] FIG. 5 further discloses that the angle K between the surfaces of the end reliefs 38, 39 and the longitudinal axis of the internal teeth 22 is between 9 and 16 degrees.

[0051] Figure 7 shows an axial end view of the rotating sleeve 17. Both Figure 7 and the cross-sectional view of Figure 8 show that the rear ends of the internal teeth 22 also have end reliefs 38, 39.

[0052] The rotating sleeves disclosed in Figures 5, 7, 8, 9, and 11-13 may be the inner rotating sleeve component 17a shown in Figure 3, around which an outer rotating sleeve component is disposed. In other words, the rotating sleeve arrangement may include an inner first sleeve component and an outer second sleeve component that can be disposed inside each other. In Figure 7, reference numeral 41 indicates the surrounding outer second sleeve component by a dashed line. The inner first sleeve has internal teeth with end reliefs, and teeth or other transmission elements are present between the sleeve components to transmit torque between the sleeve components. In another possible embodiment, the rotational torque is transmitted directly to an integral rotating sleeve with internal and external teeth and end reliefs for the internal teeth.

[0053] 9 and 10 show that only the first end reliefs 38 are provided on the internal teeth 22 of the rotating sleeve 17. Therefore, in this rotating sleeve 17, the ends of the internal teeth 22 are protected from high loads only in the normal direction of rotation R. Furthermore, only the first flank surface 32 of the internal teeth is provided with lubrication grooves 23. In the reverse direction of rotation, the loads are smaller, so end reliefs and lubrication grooves are not necessarily required on the opposing second flank surface 33.

[0054] The end reliefs 38 of the internal teeth 22 shown in Figures 9 and 10 have been produced by milling techniques, so that some additional marks 42 made by the chip removal tool can be seen on the inner surface of the rotating sleeve 17. If the end reliefs 38, 39 are produced by a wire-cut method based on electrical discharge machining, such marks are not present, which is clear from an examination of Figures 5 to 8.

[0055] 11 discloses a rotating sleeve 17 which, although not covered by the subject matter of the claims, differs from the previously shown rotating sleeves in that there are no lubrication grooves on the flanks 32, 33 of the internal teeth 22. End reliefs 38, 39 are provided at both ends of the internal teeth 22.

[0056] 12 discloses a rotating sleeve 17 which is not covered by the subject matter of the claims but which has end reliefs 38, 39 only at the rear ends of the internal teeth 22. Also, the flanks 32, 33 of the internal teeth do not have lubrication grooves formed thereon.

[0057] FIG. 13 discloses similar features to FIG. 5 above, but more clearly shows that the ends of the internal teeth 22 can be provided with end reliefs 38, 39.

[0058] The drawings and the associated description are intended only to illustrate the concept of the invention, in details which may vary within the scope of the claims.

Claims

1. A rotating sleeve (17) mountable around a shank adapter (8) of a rock drill (6), comprising: the rotating sleeve (17) comprises a number of internal teeth (22) provided with opposing first flank surfaces (32) and second flank surfaces (33) for transmitting rotation to the shank adapter (8); The internal teeth (22) have end faces (34) at both ends in the longitudinal direction of the internal teeth (22), the internal tooth (22) is provided with at least a first end relief (38) including a first chamfer between the first flank surface (32) and the end face (34); At least the first flank surface (32) is provided with a lubrication groove (23); Both ends of the lubrication groove (23) are open to the end reliefs (38, 39). A rotating sleeve (17) characterized by:

2. The internal tooth (22) is provided with a second end relief (39) having a second chamfer between the second flank surface (33) and the end surface (34).

2. The rotating sleeve (17) according to claim 1, characterized in that:

3. The rotating sleeve (17) comprises an inner first sleeve component (17a) and an outer second sleeve component (17b) which can be arranged inside each other, and the inner first sleeve component (17a) comprises the internal teeth (22) provided with the end reliefs (38, 39).

2. The rotating sleeve (17) according to claim 1, characterized in that:

4. the angle (K) between the surface of the end reliefs (38, 39) and the longitudinal axis of the internal teeth (22) is between 9 and 16 degrees; 2. The rotating sleeve (17) according to claim 1, characterized in that:

5. The end reliefs (38, 39) are formed by a wire cutting method based on electrical discharge machining.

2. The rotating sleeve (17) according to claim 1, characterized in that:

6. A main body (12); an impact device (9) for generating an impact pulse (IP); a shank adapter (8) for receiving said impact pulses (IP) and transmitting them as stress waves to a drilling tool (7) connectable to said shank adapter (8); a rotation device (10) for rotating the shank adapter (8) about its longitudinal axis; a rotating sleeve (17) surrounding the shank adapter (8) and transmitting torque from the rotating device (10) to the shank adapter (8); Equipped with The rotating sleeve (17) is as defined in any one of claims 1 to 5. A rock drill (6) characterized by:

7. A method of manufacturing a rotating sleeve (17) for a rock drill (6), the rotating sleeve (17) being mountable around a shank adapter (8) for transmitting torque between a rotating device (10) and the shank adapter (8), The method comprises: providing the rotating sleeve (17) with several internal teeth (22), the internal teeth (22) including a first flank surface (32) and a second flank surface (33); The internal teeth (22) are provided with end faces (34) at both ends in the longitudinal direction of the internal teeth (22); Including, chamfering the edge between the first flank surface (32) and the end face (34) of the internal tooth (22) to provide an end relief (38, 39) for the internal tooth (22); providing a lubrication groove (23) on at least the first flank surface (32), the lubrication groove (23) having both ends opening into the end reliefs (38, 39); A method comprising:

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