Background of the invention
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The invention relates to a rotating sleeve of a rock drilling machine. The rotating sleeve is mountable around a shank adapter and is intended for transmitting rotation torque between a rotation device and the shank adapter.
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The invention further relates to a rock drilling machine and to a method of manufacturing a rotating sleeve of a rock drilling machine.
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The field of the invention is defined more specifically in the preambles of the independent claims.
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In mines and at other work sites different type of rock drilling rigs are used. The rock drilling rigs are provided with one or more booms and rock drilling machines are arranged at distal ends of the booms. The rock drilling machine comprises an impact device provided with an impact piston which is configured to provide a drilling tool with impact pulses via a shank adapter. The shank adapter is configured to transmit impact pulses and torque from the rock drilling machine to the drilling tool. Around the shank adapter is a rotating sleeve which is rotated by a rotation device. The rotating sleeve comprises several internal teeth which match with teeth or splines of the shank adapter. The internal teeth are subjected to high stresses during the rotation. In known constructions some disadvantages have been detected in the rotating sleeves and especially regarding durability of their internal teeth.
Brief description of the invention
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An object of the invention is to provide a novel and improved rotating sleeve, a rock drilling machine equipped with such rotating sleeve, and a method for manufacturing a rotating sleeve of a rock drilling machine.
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The rotating sleeve according to the invention is characterized by the characterizing features of the first independent apparatus claim.
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The rock drilling machine according to the invention is characterized by the characterizing features of the second independent apparatus claim.
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The method according to the invention is characterized by the characterizing features of the independent method claim.
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An idea of the disclosed solution is that a rotating sleeve, which is mountable around a shank adapter of a rock drilling machine, comprises several internal teeth provided with opposing first flank surfaces and second flank surfaces for transmitting rotation to the shank adapter. The internal teeth have end surfaces at longitudinal ends of the teeth. Further, the teeth are provided with at least first end reliefs comprising first chamfers between the first flank surfaces and the end surfaces.
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In other words, each internal tooth of the rotating sleeve is provided with one or more end reliefs wherein sharp edges between the flank surfaces and the end surfaces are beveled or chamfered. The teeth may have the end reliefs at one end or at both ends.
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An advantage of the disclosed solution is that loadings directed to the end portions of the teeth can be decreased due to the end reliefs. This way material breaks at the end portions of the internal teeth can be avoided and durability of the rotating sleeve can be improved. Then, service intervals may be longer and effective drilling process can be ensured. Further, the solution allows use of greater torques when the risks for tooth end breaks can be solved.
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According to an embodiment, the internal teeth are spur teeth i.e., the teeth are straight. The internal teeth having straight, and elongated configuration are easy to produce, and they allow axial movement between the rotating sleeve and the shank adapter during the use.
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According to an embodiment, the internal teeth are alternatively obliquely toothed teeth or twisted teeth i.e., the teeth are not straight.
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According to an embodiment, length of the rotating sleeve is greater than diameter of the rotating sleeve, whereby the teeth are relatively long in axial direction.
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According to an embodiment, length of the rotating sleeve is multiple in relation to diameter of the rotating sleeve.
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According to an embodiment, the mentioned first flank surfaces are configured to transmit rotation when the shank is turned in drilling direction, and the mentioned second flank surfaces are configured to transmit rotation when the shank is turned in reverse direction.
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According to an embodiment, the end reliefs have planar surfaces. In other words, the chamfers between the first flank surfaces and the end surfaces are planar. Then the chamfers have as simple surface shape as possible to be manufactured.
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According to an embodiment, the end reliefs have alternatively curved surfaces. In other words, the sharp edges between the first flank surfaces and the end surfaces are rounded.
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According to an embodiment, the teeth are provided with second end reliefs comprising second chamfers between the second flank surfaces and the end surfaces. In other words, all four sharp corners of the tooth are chamfered to provide the four end reliefs for the tooth. An advantage of this embodiment is that the teeth ends are protected against loadings also in the direction of the reverse rotation.
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According to an embodiment, the teeth are provided with end reliefs only at one end of the teeth. In other words, corners of each tooth are chamfered either at a front or rear end of each tooth. The end reliefs can be formed for example to that end which is subjected to greater loadings. In a further embodiment, the teeth are provided with first or second end reliefs only at one end of the teeth. All different combinations for placing the end reliefs are possible.
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According to an embodiment, the rotating sleeve comprises an inner first sleeve component and an outer second sleeve component arrangeable inside one another, and wherein the inner first sleeve comprises the internal teeth provided with the end reliefs. In other words, the rotating sleeve has two-part configuration wherein rotation torque is transmitted on an outer surface of the outer second sleeve component and wherein between the inner first sleeve component and the outer second sleeve component is a gear system for transmitting the torque between the sleeve components.
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According to an embodiment, the inner first sleeve component is a changeable wearing component.
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According to an embodiment, the inner first sleeve component is made of bronze or corresponding slide bearing material.
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According to an alternative embodiment, the rotating sleeve has single piece configuration. Then, the rotating sleeve comprises internal teeth with the end reliefs, and external teeth for receiving torque from a rotation device.
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According to an embodiment, the rotating sleeve has external teeth for receiving torque from a rotation device either directly (one piece structure) or indirectly (via an outer second sleeve component).
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According to an embodiment, at least the first flank surfaces comprise lubricating grooves. In other words, each first flank surface has one axial lubricating groove for providing lubricant to contact surfaces between splines of the shank adapter and the first flank surfaces of the rotating sleeve.
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According to an embodiment, depth and width of the mentioned lubricant groove are both at least 2 mm.
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According to an embodiment, depth of the lubricant groove is 2 - 4 mm.
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According to an embodiment, both ends of the lubricant groove are open to the end reliefs. In other words, the lubricant groove has no closed ends but instead extends end to end of the tooth. In constructions where the lubricant grooves extend for the entire length of the internal teeth, the end reliefs protect well from high loadings areas surrounding the lubricant grooves at the end portions of the teeth.
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According to an embodiment, the flank surfaces are without lubricating grooves. Then the lubricating may be based on air-oil mist, for example.
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According to an embodiment, length of the end relief is 8 - 14% of total length of the internal tooth.
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According to an embodiment, transverse dimension of the end relief is 10 - 16% of distance between two opposing parallel flank surfaces.
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According to an embodiment, an angle between a surface of the end relief and longitudinal axis of the internal tooth is 9 - 16°.
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According to an embodiment, shape of the end relief corresponds to a truncated triangle.
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According to an embodiment, the end reliefs are formed by means of a wire cutting method based on electrical discharge machining (EDM). In other words, the end reliefs are manufactured by a wire EDM or spark machining techniques.
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According to an alternative solution the end reliefs are formed by means of a chip removal milling tool.
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According to an embodiment, the disclosed solution relates to a rock drilling machine, 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 turning the shank adapter around its longitudinal axis; and a rotating sleeve surrounding the shank adapter and transmitting torque from the rotation device to the shank adapter. Further, the rotating sleeve is in accordance with any one of the features and embodiments disclosed in this document.
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According to an embodiment, the disclosed solution relates to a method of manufacturing a rotating sleeve of a rock drilling machine, and wherein the rotating sleeve is mountable around a shank adapter for transmitting torque between a rotation device and the shank adapter. The method comprises: providing the rotating sleeve with several internal teeth wherein the internal teeth comprise first flank surfaces and second flank surfaces; and providing the internal teeth with end surfaces at longitudinal ends of the teeth. The method further comprises chamfering edges between the first flank surfaces and the end surfaces of the teeth for providing the teeth with end reliefs. The end reliefs protect the teeth ends form breakages caused by excessive loadings.
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The above disclosed embodiments may be combined to form suitable solutions having those of the above features that are needed.
Brief description of the figures
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Some embodiments are described in more detail in the accompanying drawings, in which
- Figure 1 is a schematic side view of a rock drilling rig for surface drilling,
- Figure 2 is a schematic view of a hydraulic rock drilling machine,
- Figure 3 is a schematic and cross-sectional side view of a front part of a rock drilling machine,
- Figure 4 is a schematic side view of a shank adapter provided with splines at a rear end for receiving rotating torque,
- Figure 5 is a schematic view of a rotating sleeve inside which a shank adapter with splines can be arranged,
- Figure 6 is a schematic view of an internal tooth of a rotating sleeve seen in axial direction of the rotating sleeve,
- Figure 7 is a schematic and axial view of the rotating sleeve shown in Figure 5,
- Figure 8 is a schematic and cross sectional side view of the rotating sleeve shown in Figures 5 and 7,
- Figure 9 is a schematic view of a rotating sleeve provided with internal teeth with milled end reliefs,
- Figure 10 is a schematic view of a milled internal tooth of a rotating sleeve seen in axial direction of the rotating sleeve,
- Figure 11 is a schematic view of a rotating sleeve provided with internal teeth without lubricating grooves,
- Figure 12 is a schematic view of a rotating sleeve provided with end reliefs only at rear ends of internal teeth of the sleeve, and
- Figure 13 is a schematic view of a rotating sleeve provided with end reliefs at both ends of internal teeth of the sleeve.
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For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements.
Detailed description of some embodiments
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Figure 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 impact 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.
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Figure 2 discloses a rock drilling machine 6 comprising a body 12, an impact device 9, a rotating device 10 and a gear housing G. Mounted at a front end FE of the gear housing G 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.
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Figure 3 discloses a gear housing G of a rock drilling machine 6. An impact surface 15 of a shank adapter 8 receives impact pulses from a percussion piston 16 and rotation torque is transmitted to the shank adapter 8 by means of a rotating sleeve 17. The rotating sleeve 17 is rotated by a rotating device 10 coupled to the rotating sleeve 17 by means of gears 18. The rotating sleeve 17 may be a single piece transmission element or it may comprise two components shown in Figure 3. The two-piece configuration may comprise an inner first rotating sleeve component 17a and an outer second rotating sleeve component 17b between which there are gears 19. A rear most end part of the shank adapter 8 may be surrounded by means of a shank sleeve 20 for transmitting axial forces in drilling direction A and in opposite reverse direction for the shank adapter 8. The shank adapter 8 comprises splines 21 or corresponding teeth which are in contact with internal teeth 22 of the rotating sleeve 17.
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Flank surfaces of the internal teeth 22 may comprise lubricating grooves 23 for gear contact between the rotating sleeve 17 and the shank adapter 8. The lubricating groves 23 may be open at both ends and lubricating oil may be directed to the groove through lubricating channels 24. In Figure 3 flows of lubricating medium are shown by arrows as well as different lubricating channels and routes. Some examples of the routes are marked by means of reference numerals 25, 26.
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Figure 4 discloses a shank adapter 8 wherein a coupling head 27 comprises a shoulder 28 and a connecting thread 29. Alternative coupling end arrangements may also be implemented. At a rear end 30 of the shank adapter 8 may be a portion for receiving impact pulses IP and provided with an impact surface 15. There are also splines 21 for transmitting rotation R for the shank adapter 8. At a middle section 31 is an opening 32 for leading flushing fluid inside the shank adapter and to a drilling tool 7.
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Figure 5 discloses a rotating sleeve 17 inside which a shank adapter of a rock drilling machine can be mounted. The rotating sleeve 17 comprises several internal teeth 22 provided with opposing first flank surfaces 32 and second flank surfaces 33 for transmitting rotation to the shank adapter. The internal teeth 22 have end surfaces 34 at longitudinal ends of the teeth. The rotating sleeve 22 can be rotated in direction R during normal drilling and in reverse direction by means of a rotation device. On an outer surface of the rotating sleeve 22 there are external teeth 35 for transmitting rotating torque to the rotating sleeve 22. The external teeth 22 may form the gear 19 shown in the previous Figure 3. The external tooth 35 may be located at a front end part 36 of the rotating sleeve 17 and the rear end part 37 may be without the gears.
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Figure 5 further shows that the internal teeth 22 are provided with end reliefs 38, 39 between the end surfaces 34 and the flank surfaces 32, 33. Figure 6 shows one internal tooth 22 of the rotating sleeve in detailed, 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.
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Figures 5 - 8 show that the first flank surfaces 32 of the internal teeth 22 comprise lubricating grooves 23. The lubricating grooves 23 can extend end to end of the internal teeth. Thereby, both ends of the lubricant groove are open to the first end reliefs 38, 39. On a front face surface there may be lubricating channels or grooves 40 for conducting the lubricating fluid.
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Figure 5 further discloses that an angle K between a surface of the end relief 38, 39 and longitudinal axis of the internal tooth 22 is 9 - 16°.
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Figure 7 shows the rotating sleeve 17 axially and seen from its end direction. Figure 7 and the cross-sectional Figure 8 both show that there are end reliefs 38, 39 also at rear ends of the internal teeth 22.
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The rotating sleeves disclosed in Figures 5,7,8,9 and 11 - 13 may be inner rotating sleeve components 17a shown in Figure 3 and around which outer rotating sleeve components may be arranged. In other words, a rotating sleeve arrangement may comprise the inner first sleeve component and the outer second sleeve component arrangeable inside one another. In Figure 7 reference 41 indicates by means of broken lines the surrounding outer second sleeve component. The inner first sleeve comprises the internal teeth provided with the end reliefs and between the sleeve components are teeth or other transmission elements for transmitting torque between the sleeve components. In another possible embodiment, rotating torque is transmitted directly on one-piece rotating sleeve comprising internal and external teeth and end reliefs on internal teeth.
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Figures 9 and 10 show that internal teeth 22 of a rotating sleeve 17 are provided with first end reliefs 38 only. Thus, in this rotating sleeve 17 ends of the internal teeth 22 are protected against high loadings in normal rotation direction R only. Further, only first flank surfaces 32 of the internal teeth are provided with lubricating grooves 23. In reverse rotation direction loadings are minor wherefore the end reliefs and the lubricating grooves are not necessarily needed on opposing second flank surfaces 33.
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The end reliefs 38 of the internal teeth 22 shown in Figures 9 and 10 are produced by milling technique, wherefore some additional marks 42 produced by a chip removing tool can be seen on inner surface of the rotating sleeve 17. When the end reliefs 38, 39 are manufactured by means of a wire cutting method based on electrical discharge machining no such markings exist, which is apparent when examining Figures 5 - 8.
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Figure 11 discloses a rotating sleeve 17 which differs from the previously shown rotating sleeves in that there are no lubricating grooves on flank surfaces 32, 33 of the internal teeth 22. The internal teeth 22 are provided with end reliefs 38, 39 at their both ends.
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Figure 12 discloses a rotating sleeve 17 comprising end reliefs 38, 39 only at rear ends of internal teeth 22. Further, flank surfaces 32, 33 of the internal teeth are without lubricating grooves.
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Figure 13 discloses similar features as the previous Figure 5 but shows more clearly that ends of internal teeth 22 can be provided with the end reliefs 38, 39.
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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.
