Shank sleeve assembly, rock drill and method

Abstract

Shank sleeve assembly, rock drill, and method. The assembly (26) comprises a shank bushing (27) having a two-piece configuration comprising a first bushing component (27a) and a second bushing component (27b) that are mountable around a shank adapter (8) in a rock drill (6) and are abutting and connectable to each other. The assembly further comprises a bearing bushing (30) that is positioned to surround the two-piece shank bushing and allows rotation between the shank bushing and the bearing bushing.

Description

Technical Field

[0001] The present invention relates to a shank sleeve assembly for a rock drill, comprising a split sleeve surrounding a shank adapter.

[0002] The present invention further relates to a method of providing a rock drill and a shank bushing having a two-piece configuration.

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

Background Art

[0004] In mines and at other work sites, various types of rock drilling rigs are used. The rock drilling rig is provided with one or more booms, and a rock drill is disposed at the distal end of the boom. The rock drill comprises an impact device provided with an impact piston configured to provide an impact pulse to an excavation tool via a shank adapter. The shank adapter is configured to transmit an impact pulse and torque from the rock drill to the excavation tool. The shank adapter may be axially supported by a shank bushing. Depending on the configuration of the rock drill and the dimensions of the shank adapter, it may be necessary to use a split shank bushing to enable installation and removal. However, some drawbacks have become apparent in known solutions, particularly with regard to wear of the shank bushing.

Summary of the Invention

[0005] An object of the present invention is to provide a novel and improved shank sleeve assembly, rock drill, and method.

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

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

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

[0009] The proposed solution involves a two-piece shank bushing assembled to surround the shank adapter of a rock drill, with the shank bushing then surrounded by a bearing bushing. This arrangement allows for rotation of the shank bushing.

[0010] In other words, the shank bushing has a split structure comprising at least two compatible bushing components surrounded by a separate bearing bushing that provides support to the bushing components.

[0011] The advantage of the disclosed solution is that a shank bushing with a segmented structure can be made rotatable when the bushing components are properly supported by bearing bushings. Enabling rotation of the shank bushing is beneficial because, as a result, wear is evenly distributed across the surface of the shank bushing components. The moving shank adapter does not lead to continuous wear on the same surface area of ​​the shank bushing, and wear on the shank adapter is also reduced. The proper support provided by the surrounding bearing bushings ensures smooth rotation of the shank bushing components. Improved wear resistance means a longer operating life of the shank bushing and less maintenance work.

[0012] According to one embodiment, a two-piece shank bushing is rotatably mounted to a bearing bushing. In other words, the connection between the two-piece shank bushing and the surrounding bearing bushing allows for rotational movement between them.

[0013] According to one embodiment, the shank sleeve assembly does not have a surface of rotation between the shank bushing and the bearing bushing. However, there is a surface of rotation on the outer surface of the bearing bushing to enable the rotation of the assembly. The advantage of this solution is that there is a seamless, uniform surface in the rotational connection of the assembly. Furthermore, the manufacturing and dimensional accuracy of the two-piece components are not important because they rotate.

[0014] According to one embodiment, there is a connection between a two-piece shank bushing and a bearing bushing that allows only limited axial relative movement between the two-piece shank bushing and the bearing bushing. In other words, relative rotation between the shank bushing and the bearing bushing is prevented, but axial movement is possible. The connection may include, for example, a spline or other form of surface that transmits torque but allows axial movement.

[0015] According to one embodiment, both components of a two-piece shank bushing are immovably attached to a bearing bushing. The components of the shank bushing can be fixed to the bearing bushing, for example, by screw fastening.

[0016] According to one embodiment, there is a gap fit between the split shank bushing and the bearing bushing.

[0017] According to one embodiment, the assembly is supported by a cleaning housing, which is part of the frame structure of the rock drill. The cleaning housing forms a space around a defined portion of the shank adapter, allowing for the supply of cleaning fluid to the cleaning fluid passage of the shank adapter through that space.

[0018] According to one embodiment, the disclosed solution allows for the use of increased diameters in the rotary joints of the assembly, which is beneficial for rigidity and wear resistance.

[0019] According to one embodiment, the solution also enables the use of a shank adapter with a shoulder, in other words, a shank adapter that implements so-called shoulder-driven contact on a threaded rock tool coupling.

[0020] In this specification, a bushing may also be called a sleeve; in other words, a bushing is an elongated component having an inner circumference and an outer circumference.

[0021] According to one embodiment, the bearing bushing is provided with a rotating surface on its outer circumference, enabling it to be rotatably mounted. In other words, rotation can occur between the split shank bushing and the bearing bushing, and between the bearing bushing and the structure surrounding it. This provides two rotating joints. The advantage of this embodiment is that the rotational movement in the shank sleeve assembly is divided into two rotating joints, in other words, on the inner and outer circumferences of the bearing bushing, thereby reducing wear compared to a situation where only one rotating joint is implemented. When the rotational movement of the shank adapter is divided into two rotating joints, less rotational movement and wear is directed to a single rotating joint.

[0022] According to one embodiment, the rotating surface of the bearing bushing has a rotationally symmetrical outer surface.

[0023] According to one embodiment, the bearing bushing has a uniform, non-divided structure, thereby having a solid structure capable of providing rigid support to a shank bushing having a divided structure. The bearing bushing forms a case-like structure around the shank bushing.

[0024] According to an alternative embodiment, the bearing bushing is not a rotatable component, but rather is supported by a surrounding frame portion to prevent it from moving during the operation of the rock drill. In this embodiment, rotation occurs between the shank bushing and the inner surface of the bearing bushing.

[0025] According to one embodiment, the shank sleeve assembly further includes a wear bushing that can be arranged to surround the bearing bushing. In other words, the assembly includes three continuous sleeves, such as components arranged to overlap each other, or rather, three separate nested sleeves around the shank adapter, namely, the shank bushing, the bearing bushing, and the wear bushing. The bearing bushing is indirectly supported on the frame via the wear bushing. The advantage of this embodiment is that the wear bushing is an easily replaceable wear part that can be replaced when necessary. The wear bushing provides protection to the frame surrounding the assembly. Replacing the wear bushing is much easier and less costly than replacing or repairing the frame or replacing the bearing bushing. A further advantage of the separate wear bushing is that the wear bushing can be designed on a case-by-case basis without basic constraints regarding the frame configuration. Thereby, materials, shapes, and other characteristics can be selected more freely.

[0026] According to one embodiment, the assembly includes a total of four parts, including a one-piece wear bushing, a one-piece bearing bushing, and two halves of a split shank bushing.

[0027] According to an alternative embodiment, the assembly does not have a separate wear bushing. In that case, the frame is provided with a space for receiving the bearing bushing, or rather, the bearing bushing is directly supported on the frame.

[0028] According to one embodiment, one end of the wear bushing projects inward and includes a flange that provides an axial support surface to the bearing bushing. In other words, the flange of the wear bushing can act as an axial limiting element and can partially define the space in which the bearing bushing rotates.

[0029] According to one embodiment, the flange of the wear bushing is configured to determine the axial clearance for the bearing bushing. If an axially excessive clearance occurs due to wear, it is possible to return to the original clearance setting by replacing the wear bushing. Further, by selecting wear bushings with different dimensions, it is possible to affect the axial clearance.

[0030] According to one embodiment, the bearing bushing comprises an inward-facing shoulder at a first end portion of the bearing bushing. The shank bushing comprises a first end facing in the direction of excavation. Further, a face surface at the first end of the shank bushing can be mounted in contact with the shoulder of the bearing bushing. In other words, the components of the split shank bushing are axially supported in contact with the shoulder of the bearing bushing, thereby being properly axially supported in contact with the uniform surface of the shoulder.

[0031] According to one embodiment, the first bushing component and the second bushing component of the shank bushing can be fixed to each other such that these bushing components together form one part during use. When the bushing components are assembled and fixed to each other, the components do not radially expand so as to separate from each other during use. In this way, the designed clearance is maintained and the shank bushing operates in the designed manner.

[0032] According to one embodiment, the bushing components of the shank bushing are fixed to each other by screws or other fixing elements. An alternative is to provide a form-locking element or structure on the coupling surface of the components.

[0033] According to one embodiment, the solution may further comprise at least one sealing element, such as an O-ring, disposed on the outer surface of the bearing bushing. The sealing element can be utilized to direct the lubricating fluid for the assembly in a desired manner.

[0034] According to one embodiment, at least one of the aforementioned sealing elements of the bearing bushing, such as an O-ring, may be positioned on the outer surface of the bearing bushing and may be used to facilitate the installation of the assembly.

[0035] According to one embodiment, the disclosed solution also relates to a rock drill comprising a frame, an impact device for generating impact pulses, a shank adapter for receiving impact pulses and transmitting the received impact pulses as stress waves to a drilling tool connectable to a shank adapter, a rotating device for rotating the shank adapter about its longitudinal axis, and a shank sleeve assembly having a segmented configuration surrounding the shank adapter and a shank bushing configured to transmit axial forces between the frame and the shank adapter. Furthermore, the shank sleeve assembly conforms to the features disclosed herein.

[0036] According to one embodiment, the disclosed solution also relates to a method for providing a rock drill having a rotating shank bushing. The method includes providing a shank bushing having a two-piece configuration comprising a first bushing component and a second bushing component, and arranging the bushing component to surround the shank adapter of the rock drill. The method further includes surrounding the shank bushing with a separate bearing bushing, and enabling the two-piece shank bushing to rotate about its longitudinal axis relative to the bearing bushing.

[0037] According to one embodiment, the method further comprises rotatably supporting a bearing bushing with respect to the frame of a rock drill.

[0038] According to one embodiment, the method further comprises supporting the bearing bushing on the frame of the rock drill by a separate wear bushing that surrounds the bearing bushing.

[0039] According to one embodiment, a shoulder-contact type shank adapter is implemented.

[0040] According to one embodiment, an alternative bottom-contact type shank adapter is implemented. In this case, the coupling head of the shank adapter has coupling threads and no shoulder.

[0041] In this specification, the terms “split” and “split configuration” refer to a structure having a non-uniform rim or circumference. A structure can be split or disassembled into at least two parts or ring-shaped segments in the radial direction. Since the shank bushing has a two-part configuration, the shank bushing can be mounted and removed radially regardless of the dimensions and shape of the shank adapter.

[0042] The embodiments disclosed above can be combined to form a preferred solution having any of the required features described above.

[0043] Several embodiments are described in more detail in the accompanying drawings. [Brief explanation of the drawing]

[0044] [Figure 1] This is a schematic side view of a rock drilling rig for surface excavation. [Figure 2] This is a schematic diagram of a hydraulic rock drill. [Figure 3] This is a schematic side view of the front section of a rock drill. [Figure 4] This is a schematic cross-sectional side view of the front of the rock drill and the shank adapter equipped with a shoulder. [Figure 5] Figure 4 is a schematic cross-sectional detail view C of the shank sleeve device. [Figure 6] This is a schematic cross-sectional side view of the front end of a rock drill equipped with a shank sleeve device that can be attached and removed from the rear. [Figure 7] Figure 6 is a schematic cross-sectional detail view D of the shank sleeve device. [Figure 8] This is a schematic diagram of a shank bushing with a two-piece construction. [Figure 9] This is a schematic cross-sectional side view of the front end of a rock drill equipped with a bottom-contact type shank adapter. [Figure 10] This is a schematic cross-sectional side view of the front end of a rock drill equipped with a shank sleeve device having one support sleeve for the shank bushing. [Figure 11] Figure 10 is a schematic cross-sectional detail view E of the shank sleeve device. [Modes for carrying out the invention]

[0045] For clarity, the figures show several embodiments of the disclosed solution in a simplified form. In the figures, similar reference numbers identify similar elements.

[0046] Figure 1 shows a drilling rig 1 intended for surface drilling. The drilling rig 1 comprises a movable carrier 2 and at least one drilling boom 3 connected to the carrier 2. At the distal end of the drilling boom 3 is a drilling unit 4 provided with a feed beam 5 and a drill 6 supported on the feed beam 5. A drilling tool 7 can be connected to the drill 6. The drill 6 is equipped with a shank adapter 8 at its front end FE for connecting the drilling tool 7. The drill 6 further comprises an impact device 9 and a rotating device 10. The drill 6 can be moved on the feed beam 5 in the drilling direction A by the feed device 11. During drilling, impact pulses are generated in the rotating shank adapter 8 by the impact device, and the rotating shank adapter 8 transmits the impact pulses and torque to the drilling tool 7. A cleaning agent stream is carried through the hollow structure to the shank adapter 8 and through the drilling tool 7 to the bottom of the borehole to wash away drilling debris from the borehole.

[0047] Figure 2 discloses a rock drill 6 comprising a main body 12, an impact device 9, a rotating device 10, and a gear housing 13. A cleaning housing 14 and a shank adapter 8 are attached to the front end FE of the main body 12. A cleaning agent such as water is delivered to the cleaning housing 14 or the cleaning head by a cleaning channel 15. The cleaning housing 14 includes a frame 16 that can be detachably attached to the gear housing 13.

[0048] The impact device 9 may include an impact piston for generating impact pulses in the shank adapter 8 in the impact direction. The rotating device 10, together with a transmission means in the gear housing 13, rotates the shank adapter 8 about its longitudinal axis.

[0049] Figure 3 discloses the front end FE of the rock drill when separated from the gear housing. The front end FE comprises a cleaning housing 14 through which a shank adapter 8 is mounted. The rear end of the frame 16 of the cleaning housing 14 has a mounting surface 17 which can be mounted in contact with a corresponding mounting surface of the gear housing. The shank adapter 8 has a spline 18 or a corresponding transmission surface at its rear end portion. When the cleaning housing 14 is mounted in place, the spline 18 contacts the gear of the gear housing. The impact surface 19 of the shank adapter 8 is configured to receive impact pulses from an impact device. The opposite end of the shank adapter 8 has a connecting means 20 with a connecting thread 21. In this case, the shank adapter 8 is of the shoulder contact type and has a shoulder 22 through which the end of the drilling tool abuts and is supported when connected. The cleaning housing 14 comprises a cleaning space 24 and a supply port 23 for supplying cleaning fluid to the drilling tool via a cleaning channel 25 of the shank adapter 8, as indicated by the arrows in Figure 4.

[0050] Figure 4 discloses a shank sleeve assembly 26 comprising a shank bushing 27 mounted around a shank adapter 8 and provided with an inwardly projecting shoulder 28 for providing axial support to the shank adapter 8. The shank bushing 27 has a two-piece configuration disclosed in Figure 8. The shank bushing 27 has a first bushing component 27a and a second bushing component 27b, both provided with coupling surfaces 29 that can contact and connect with each other radially. Detail drawing C presented in Figures 4 and 5 shows that the shank sleeve assembly 26 further comprises a bearing bushing 30 that can be positioned to surround the two-piece shank bushing 27. This configuration allows for well-supported rotation between the shank bushing 27 and the bearing bushing 30. The bearing bushing 30 has a rotating surface 31 on its outer circumference. The shank sleeve assembly 26 further comprises a wear bushing 32 positioned to surround the bearing bushing 30. The rear end of the wear bushing 32 has a flange 33 that protrudes inward and provides an axial support surface for the bearing bushing 30. The front end of the wear bushing 32 is supported by contacting an axial surface formed on the frame 16.

[0051] Detailed diagram D in Figures 6 and 7 discloses a solution that differs from the solutions shown in Figures 4 and 5 in that there is no wear bushing, and instead a bearing bushing 30 is directly supported on the frame 16. The front end of the bearing bushing 30 is supported axially by contacting a shoulder 34 formed on the frame, and the rear end is supported by a locking element 35, such as a locking ring. The installation direction of the disclosed shank sleeve assembly 26 is from the rear end side, whereas in the solutions disclosed in Figures 4 and 5, the shank sleeve 27 and bearing bushing 30 are installed from the front end side.

[0052] Figures 5 and 7 further show that the bearing bushing 30 is provided with an inwardly facing shoulder 36 at the first end portion of the bearing bushing 30. The shank bushing 26 is supported in contact with the shoulder 36.

[0053] Figure 9 discloses a solution that differs from the solution shown in Figure 4, in that the shank adapter 8 is of a different type and does not have a shoulder. The shank sleeve device 26 may be as disclosed in detail diagram C in Figure 5.

[0054] Figure 10 discloses a solution that differs from the solution shown in Figure 6, in that the shank adapter 8 is of a different type and includes a shoulder. Furthermore, there is no separate locking element 35 to prevent axial movement of the bearing bushing in the rearward direction; instead, the bearing bushing 30 extends to the same extent as the frame 16.

[0055] In the cross-sectional views of Figures 4, 6, 7, 9, and 10, it is not possible to confirm that the shank sleeve 27 has a segmented structure. However, the segmented structure is shown in Figure 8. The components or halves 27a, 27b may be bolted together or connected to each other in any other way, such as by shape locking. Together, the halves 27a, 27b define an axial opening into which the shank adapter can be mounted. The structure of the bearing sleeve 27 and the wear sleeve 30 may be uniform without a segmented structure.

[0056] The drawings and related descriptions are for illustrative purposes only and illustrate the idea of ​​the present invention. The present invention may be modified in detail within the claims.

Claims

1. A shank sleeve assembly (26) that can be attached around the shank adapter (8) in a rock drill (6), The sleeve assembly (26) comprises a shank bushing (27) having an inner surface facing the shank adapter (8) and a shoulder (28) protruding inward, and an outer surface, The shank bushing (27) has a two-piece configuration comprising a first bushing component (27a) and a second bushing component (27b), both of which are provided with coupling surfaces (29) that abut against each other and can be connected radially. In the shank sleeve assembly (26), the shank sleeve assembly (26) further comprises a bearing bushing (30) that can be positioned to surround a two-piece shank bushing (27), The bearing bushing (30) is provided with an inwardly facing shoulder (36) at the first end portion of the bearing bushing (30), The shank bushing (27) has a first end facing the direction of excavation, This allows the face surface at the first end of the shank bushing (27) to contact and be mounted to the shoulder (36) of the bearing bushing (30). A shank sleeve assembly (26) characterized by the above.

2. The two-piece shank bushing (27) is rotatably mounted to the bearing bushing (30). The assembly according to claim 1, characterized in that

3. Only limited axial movement is permitted between the two-piece shank bushing (27) and the bearing bushing (30). The assembly according to claim 1, characterized in that

4. Both components of the two-piece shank bushing (27) are fixedly attached to the bearing bushing (30). The assembly according to claim 1, characterized in that

5. The bearing bushing (30) is provided with a rotating surface (31) on its outer circumference, enabling it to be rotatably mounted. The assembly according to any one of claims 1 to 4, characterized in that

6. The shank sleeve assembly (26) further comprises a wear bushing (32) that can be positioned to surround the bearing bushing (30). The assembly according to any one of claims 1 to 5, characterized in that

7. One end of the wear bushing (32) is provided with a flange (33) that protrudes inward and provides an axial support surface to the bearing bushing (30). The assembly according to claim 6, characterized in that

8. The first bushing component (27a) and the second bushing component (27b) are detachably fixed to each other in order to form a single uniform part together. The assembly according to any one of claims 1 to 7, characterized in that

9. Frame (12, 16) and An impact device (9) for generating an impact pulse, A shank adapter (8) receives the impact pulse and transmits the received impact pulse as a stress wave to a drilling tool (7) that can be connected to the shank adapter (8), A rotating device (10) for rotating the shank adapter (8) about its longitudinal axis, A shank sleeve assembly (26) having a divided structure surrounding the shank adapter (8) and a shank bushing (27) configured to transmit axial force between the frame (16) and the shank adapter (8), and Equipped with, The shank sleeve assembly (26) is as described in any one of claims 1 to 8. A rock drill (6) characterized by the following features.

10. A method for providing a rock drill (6) having a rotating shank bushing (27), To provide a shank bushing (27) having a two-piece configuration comprising a first bushing component (27a) and a second bushing component (27b), The bushing components (27a, 27b) are arranged to surround the shank adapter (8) of the rock drill (6), The shank bushing (27) is surrounded by a separate bearing bushing (30). Includes, In the first end portion of the bearing bushing (30), an inwardly facing shoulder (36) is provided on the bearing bushing (30), The shank bushing (27) is provided with a first end facing the direction of excavation, A face surface is attached to the first end of the shank bushing (27) that abuts against the shoulder (36) of the bearing bushing (30). A method characterized by...

11. The two-piece shank bushing (27) is made capable of rotating around its longitudinal axis relative to the bearing bushing (30). The method according to claim 10, characterized by...

12. To prevent rotational movement between the two-piece shank bushing (27) and the bearing bushing (30), To enable limited axial relative movement between the two-piece shank bushing (27) and the bearing bushing (30) The method according to claim 10, characterized by...

13. The components of the two-piece shank bushing (27) are fixedly attached to the bearing bushing (30). The method according to claim 10, characterized by...

14. The bearing bushing (30) is rotationally supported with respect to the frame (16) of the rock drill. The method according to any one of claims 11 to 13, characterized by...

15. The bearing bushing (30) is supported by the frame (16) by a separate wear bushing (32) surrounding the bearing bushing (30). The method according to claim 14, characterized by...

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