Rotary drive arrangement for a drill rod

Abstract

The invention relates to a rotary drive arrangement for a drill rod having an outer tube and an inner rod extending at least in a section within the outer tube, in particular for double-head drilling and / or overburden drilling, having a first gear housing for driving the inner rod in rotation and a second gear housing for driving the outer tube in rotation, wherein the first gear housing and the second gear housing are independent of one another. According to the invention, it is provided that the first gear housing and the second gear housing are supported in and surrounded by a common gear housing.

Description

Technical Field

[0001] According to the preamble of claim 1, the present invention relates to a rotary drive arrangement for a drill pipe having an outer tube and an inner rod extending in at least a section within the outer tube, particularly for double-head drilling and / or overburden drilling, the rotary drive arrangement having a first gearbox for rotaryly driving the inner rod and a second gearbox for rotaryly driving the outer tube, wherein the first gearbox and the second gearbox are independent of each other. Background Technology

[0002] For example, such a rotary drive arrangement is known from EP1936109B1. In this known rotary drive arrangement, a compact overall construction is achieved because a total of three rotary drives are positioned above the generally annular gearbox unit for driving the inner rod. The annular gearbox unit for driving the outer tube is arranged below and at a distance from the gearbox unit for driving the inner rod. The spaced-apart gearbox units are connected to each other via supports.

[0003] This rotary drive arrangement is used in drilling equipment to drive drill pipes for double-headed drilling or overburden drilling. The drill pipe has an inner rod with drilling tools and an outer tube with another annular drilling tool, which coaxially surrounds the inner rod. The inner rod and outer tube can be driven in the same or opposite directions with the same or different torques and rotational speeds. Therefore, boreholes can be efficiently produced underground or in rock. Summary of the Invention

[0004] The present invention aims to provide a rotary drive arrangement for drill pipes that achieves particularly efficient use while having a compact structure.

[0005] This objective is achieved by a rotary drive arrangement having the features of claim 1. Preferred embodiments of the invention are set forth in the dependent claims.

[0006] The rotary drive arrangement according to the invention is characterized in that the first gearbox and the second gearbox are supported in and surrounded by a common gearbox housing.

[0007] Therefore, a particularly compact rotary drive arrangement was achieved. This minimizes material expenditures required in manufacturing and reduces the overall weight of the rotary drive arrangement. This offers considerable advantages when used in drilling equipment. Since the rotary drive arrangement typically moves along a vertical derrick that can be 10 to 20 meters or longer, the weight reduction of the rotary drive arrangement, which can be displaced and supported thereon, translates to improved anti-tilting performance of the equipment. Furthermore, the more compact construction effectively allows for greater drill pipe displacement distances.

[0008] When the drill pipe is removed from the borehole, the rotary drive arrangement must be retracted by a traction device (usually a winch). Therefore, the weight reduction of the rotary drive arrangement also results in a reduction of the load during removal, which allows greater traction force to be applied to the drill pipe, and thus enables more efficient drilling operations.

[0009] A preferred embodiment of the invention comprises the fact that the gearbox housing has a central support extending substantially perpendicular to the drilling axis and dividing the gearbox housing into a first gearbox compartment facing away from the drilling tool and a second gearbox compartment facing the drilling tool. Due to this arrangement of the central support, the two gearboxes can be arranged such that they are further functionally separated from each other, wherein a good force distribution is achieved by arranging the gearboxes on both sides of the central support, resulting in a particularly stable housing structure.

[0010] Another preferred development of the invention lies in the fact that the central support has a channel for the inner rod. In this way, the inner rod can protrude further rearward from the drilling tool side through the central support. The two gearbox compartments can be fluidly connected via the channel, for example, by lubrication of a gearbox for joint operation. On the rearward side away from the drilling tool side, the gearbox housing can be sealed relative to the inner rod by a simple sealing device. On one hand, towards the drilling tool side, the gearbox housing can be sealed relative to the inner rod by a sealing device, and on the other hand, the gearbox housing can be sealed relative to the outer rod or the output unit for the outer rod by another sealing device.

[0011] According to embodiments of the invention, it is particularly advantageous that a first gearbox for driving the inner rod is arranged in a first gearbox compartment, and a second gearbox for driving the outer tube is arranged in a second gearbox compartment. In particular, this arrangement provides the possibility of displacement of the inner rod relative to the outer tube, in which case the inner rod can move rearward relative to the gearbox housing. Due to this displaceability of the inner rod relative to the outer tube, the drilling tools on the inner rod can be arranged at the same height relative to the drilling tools on the outer rod, or, depending on the corresponding drilling method, can be arranged ahead of or behind them.

[0012] According to another development, the compactness of the rotary drive arrangement is improved further because the gearbox housing has at least one first inlet opening for at least one first drive shaft of at least one first rotary drive; and at least one second inlet opening for at least one second drive shaft of at least one second rotary drive. Preferably, two drive shafts are provided for the outer tube and one drive shaft for the inner rod. However, in each case, two or more drive shafts may also be provided for the outer tube and the inner rod. Essentially, the inner rod may also be driven by two drive shafts, while the outer tube is driven by only a single drive shaft.

[0013] In this arrangement, compactness and force distribution are still improved because at least one first inlet opening is located on one side of the central support and because at least one second inlet opening is designed on the opposite side of the central support in the gearbox housing. Preferably, the inlet opening for the drive shaft in the gearbox housing is located in the area of ​​the gearbox housing between the drilling axis and the derrick or drill string on which the rotary drive arrangement is disposed.

[0014] According to another embodiment of the invention, particularly good force transmission is achieved because the first gearbox has a first spur gear and / or the second gearbox has a second spur gear, each of which is rotatably supported in a gearbox housing. The respective spur gears can be engaged via corresponding teeth on the drive pinions of the respective drive shafts.

[0015] In conjunction with this, it is particularly advantageous to arrange a first output element for driving the inner rod on the first spur gear, the first output element being connected to the inner rod in a torsional but axially displaceable manner. Therefore, external teeth with a certain axial extension are designed on the outer side of the inner rod, this axial extension having a length greater than the width of the spur gear, thereby enabling axial displacement of the first spur gear relative to it. Thus, the inner rod can be axially displaced relative to the first gearbox, while simultaneously achieving torque transmission.

[0016] Another preferred embodiment of the invention involves the fact that a second output element for driving an outer tube is mounted on a second spur gear, the outer tube being able to be mounted on the second output element in a torsion-resistant manner. Specifically, the second output element is a flange-shaped attachment element, and the outer tube, more particularly, the drill pipe, is releasably mounted on the flange-shaped attachment element.

[0017] According to another development of the invention, a particularly compact construction is still achieved because the gearbox housing is arranged on a substrate, and the rotary drive is also arranged on the substrate. Therefore, the rotary drive arrangement can be provided as a unit together with the rotary drive.

[0018] Another preferred embodiment variation of the rotary drive arrangement according to the invention involves a displacement device arranged on the outer side of the gearbox housing, which is axially fixed but rotatable and connected to the inner rod for axial displacement of the inner rod relative to the gearbox housing. Specifically, the displacement device may have a positioning cylinder, more particularly, a hydraulic positioning cylinder. The displacement device is held to and securely connected to the gearbox housing. Preferably, the displacement device is connected to the rotatably driven inner rod via a rotary bearing, allowing the inner rod to continue rotating relative to the displacement device. Preferably, for this purpose, the displacement device is located on the rear side of the gearbox housing opposite to the drilling tool side.

[0019] Furthermore, the present invention includes a drilling apparatus having a derrick or drill rig, wherein a drilling drive carriage is supported in a displaceable manner along the derrick or drill rig, wherein a rotary drive arrangement according to the invention is arranged on the drilling drive carriage as previously described. The drilling drive carriage is here displaceably supported along a vertical derrick or drill rig by means of a cable traction system or by means of a positioning cylinder, which can be adjusted about several axes in space. In particular, a rotary drive arrangement with a base plate can be arranged together with a rotary actuator on the drilling drive carriage. Attached Figure Description

[0020] The invention will now be explained in more detail by way of preferred exemplary embodiments shown in the accompanying drawings. The drawings show a schematic cross-sectional view through a rotary drive arrangement according to the invention. Detailed Implementation

[0021] The rotary drive arrangement 10 shown is used to drive a double drill pipe (not depicted) around the drilling axis 5, with only a portion of the inner drill pipe 12 shown. Other inner pipe elements can be releasably mounted on the inner pipe 12 towards the drilling tool side via connecting sections 14. The outer pipe (not depicted) can be releasably attached to the connecting element 56 of the rotary drive arrangement 10 in a coaxial manner relative to the drilling axis 5.

[0022] The rotary drive arrangement 10 includes a gearbox housing 20 with a central support 22 designed to be positioned along a central plane 21 orthogonal to the drilling axis 5. The central support 22 is securely connected to a base plate 26, which allows the rotary drive arrangement 10 to be fixed to, for example, a drilling drive carriage (not depicted) of a drilling device.

[0023] The central support member 22 has circumferential wall sections 24 extending on both sides. A first side cover 25 is attached to the circumferential wall section 24 facing away from the rear of the drilling tool, thereby enclosing a first gearbox compartment 31 containing a first gearbox 40 for driving the inner rod 12. On the opposite side of the central support member 22, a second side cover 28 is mounted on the circumferential wall section 24, enclosing a second gearbox compartment 32 containing a second gearbox 50 for driving the outer tube. The central support member 22 has a centrally located channel 30 through which the inner rod 12 passes from the drilling tool side through the central support member 22 and protrudes rearward.

[0024] To drive the inner rod 12, a first rotary actuator (not depicted) with a first drive shaft 48 is arranged on the base plate 26, the first drive shaft protruding through a first inlet opening 35 into the gearbox housing 20. A first pinion 49 is designed on the first drive shaft 48, which meshes with a first external spur gear 42 of the first gearbox 40. A sleeve-shaped first output element 44 is mounted on the side of the first spur gear 42 opposite to the central support 22. The sleeve-shaped first output element 44 has internal teeth 45 on its inner side, which engage with external teeth 16 on the inner rod 12. The external teeth 16 have a greater axial length than the internal teeth 45, thereby providing a torsional-resistant connection associated with the axial displacement of the inner rod 12 relative to the first gearbox 40.

[0025] For axial displacement of the inner rod 12, a displacement device 60 is arranged on a sleeve-shaped housing shoulder 27, which follows and is fixed to the first side cover 25. The displacement device has a fixing element 62, which is securely mounted on the outer side of the housing shoulder 27. Additionally, a sleeve-shaped carriage 64 is provided, which is axially fixed but rotatable to the inner rod 12 via a rotary bearing 66. The carriage 64, and thus the inner rod 12, can be axially adjusted relative to the fixing element 62 and therefore relative to the gearbox housing 20 via a lifting cylinder (not depicted), in which case the rod-shaped linear guide 68 is arranged as an anti-torsion protection element.

[0026] In addition, the inner rod 12 may have a tubular design in which fluid, particularly concrete slurry, can be supplied to the drilling tool side via a known rotating feeder at the rear end of the inner rod 12.

[0027] On the opposite side of the central support 22, a second gearbox 50 for driving the outer tube (not shown) is arranged. For this purpose, a second rotary actuator (not shown) having a second drive shaft 58 is arranged on the base plate 26. The second drive shaft 58 protrudes into the gearbox housing 20 through the second inlet opening 36. Torque can be transmitted to the second spur gear 52 of the second gearbox 50 via the second pinion 59 on the second drive shaft 58. A sleeve-shaped second output element 54 is mounted on the side of the second spur gear 52 opposite to the central support 22. For mounting the outer tube of the double drill pipe, a cardanic connecting element 56 is mounted on the second output element 54 in a torsion-resistant manner via a transfer ring 55.

[0028] The inner rod 12 protrudes through the second output element 54. The corresponding annular gap in the housing passage is sealed by a suitable ring seal to oil-tightly seal the gearbox housing 20.

[0029] With this invention, two separate gearboxes 40, 50 are arranged within a gearbox housing 20 and enclosed by the gearbox housing 20 in an oil-tight manner. Thus, a generally compact rotary drive arrangement 10 is achieved.

Claims

1. A rotary drive arrangement for a drill pipe having an outer tube and an inner rod extending at least in a section within the outer tube for double-headed drilling and / or overburden drilling, the rotary drive arrangement having: - A first gearbox for rotating the inner rod, and - A second gearbox for rotating the outer tube. The first gearbox and the second gearbox are independent of each other. in, - The first gearbox and the second gearbox are supported in and surrounded by a common gearbox housing, and - A displacement device is arranged on the outside of the gearbox housing, the displacement device being axially fixed but rotatable to the inner rod for axial displacement of the inner rod relative to the gearbox housing; The gearbox housing has a central support member that extends substantially perpendicular to the drilling axis and divides the gearbox housing into a first gearbox compartment facing away from the drilling tool and a second gearbox compartment facing the drilling tool.

2. The rotary drive arrangement according to claim 1, Its features are, The central support has a channel for the inner rod.

3. The rotary drive arrangement according to claim 1, Its features are, The first gearbox for driving the inner rod is arranged in the first gearbox compartment, and the second gearbox for driving the outer tube is arranged in the second gearbox compartment.

4. The rotary drive arrangement according to claim 1, Its features are, The gearbox housing has at least one first inlet opening, the at least one first inlet opening being used for at least one first drive shaft of at least one first rotary drive; And at least one second inlet opening, said at least one second inlet opening for at least one second drive shaft of at least one second rotary drive.

5. The rotary drive arrangement according to claim 4, Its features are, The at least one first inlet opening is located on one side of the central support member, and The at least one second inlet opening is designed on the opposite side of the central support in the gearbox housing.

6. The rotary drive arrangement according to claim 1, Its features are, The first gearbox has a first spur gear and / or the second gearbox has a second spur gear, the first spur gear and the second spur gear being rotatably supported in the gearbox housing.

7. The rotary drive arrangement according to claim 6, Its features are, A first output element for driving the inner rod is arranged on the first spur gear, and the first output element is connected to the inner rod in a torsional but axially displaceable manner.

8. The rotary drive arrangement according to claim 6, Its features are, A second output element for driving the outer tube is mounted on the second spur gear, and the outer tube can be mounted on the second output element in an anti-torsional manner.

9. The rotary drive arrangement according to claim 4, Its features are, The gearbox housing is arranged on the base plate, and the rotary drive is also arranged on the base plate.

10. A drilling apparatus having a derrick or drill rig, wherein a drilling drive carriage is supported in a displaceable manner along the derrick or drill rig. Its features are, The drilling drive carriage is provided with a rotary drive arrangement according to any one of claims 1-9.

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