Drill drive assembly

Abstract

The invention relates to a drilling drive arrangement for driving an earth drilling tool, comprising at least one drive motor with a motor housing and a motor shaft, wherein a drive torque generated in the motor housing can be transmitted via the motor shaft, and a gearbox which is connected downstream of the drive motor and is designed to convert the drive torque, wherein the gearbox comprises an input gearbox element which receives the drive torque from the motor shaft of the drive motor, and an output gearbox element through which the drive torque converted by the gearbox can be transmitted to the earth drilling tool or a drill string.According to the invention, the motor shaft of the drive motor is at least partially designed as a hollow shaft with an inner insertion chamber on which at least one first torque transmission element is formed, and the input gear element of the transmission has a gear gear with an insertion shaft on which at least one second torque transmission element is formed, wherein the insertion shaft is detachably axially inserted into the inner insertion chamber of the motor shaft to form a rotationally fixed connection.

Description

[0001] The invention relates to a drilling drive arrangement for driving an earth drilling tool, comprising at least one drive motor with a motor housing and a motor shaft, wherein a drive torque generated in the motor housing can be transmitted via the motor shaft, and a gearbox which is connected downstream of the drive motor and is designed to convert the drive torque, wherein the gearbox comprises an input gearbox element which receives the drive torque from the motor shaft of the drive motor, and an output gearbox element through which the drive torque converted by the gearbox can be transmitted to the earth drilling tool or a drill string, according to the preamble of claim 1.

[0002] A drill drive assembly is typically located at the distal end of a drill string, away from the borehole, and is movable along a mast, as is known, for example, from DE 32 47 202 C1. For static reasons, a compact design is desirable for drill drive assemblies.

[0003] A known drilling drive arrangement is described, for example, in DE 199 06 687 B4. The device described therein is a drilling device for producing boreholes with two separately operable drive motors that transmit torque to an inner tube and an outer tube, respectively, via a gearbox. For power transmission from the motor to the gearbox, the drive motor has a motor shaft protruding from the motor housing, onto which a plug shaft with a pinion or a gear pinion is directly mounted, in particular screwed on. The drilling device includes further gears by which the torque is transmitted from the respective gear pinion to the outer tube and the inner tube, respectively.

[0004] German patent DE 44 02 487 A1 discloses a drilling unit for deep-hole drilling in which two drives are arranged axially offset from each other and act directly or indirectly on an inner or outer tube. The complex design, consisting of multiple drives and gear wheels, is prone to failure and requires significant maintenance. Furthermore, the arrangement of at least one motor to the side of the tube results in increased space requirements in the lateral area.

[0005] DE 197 04 263 C1 also discloses a drilling device in which a rotary drive with an output shaft directly drives one set of rods and drives another set of rods via a gearbox. The drives, which are designed as hydraulic motors, have a motor shaft protruding from a drive housing, to which a coupling is arranged, forming a connection to the actual drill drive shaft.

[0006] The invention is based on the objective of providing a drilling drive arrangement which enables particularly efficient use for driving an earth drilling tool.

[0007] The problem is solved by a device having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

[0008] The device according to the invention for driving an earth drilling tool is characterized in that the motor shaft of the drive motor is at least partially designed as a hollow shaft with an inner insertion chamber on which at least one first torque transmission element is formed, and that the input gear element of the gearbox has a gear gear with an insertion shaft on which at least one second torque transmission element is formed, wherein the insertion shaft is detachably axially inserted into the inner insertion chamber of the motor shaft to form a rotationally fixed connection.

[0009] A fundamental aspect of the invention lies in the fact that the motor shaft, which is at least partially designed as a hollow shaft, simplifies and improves the efficiency of power transmission. By creating a cavity within the motor shaft, the drive torque can be transmitted particularly reliably and efficiently through the insertion of a plug-in shaft, despite reduced assembly effort. Compared to previous drilling drive arrangements, the positive connection to downstream components thus takes place within the motor shaft of the drive motor. In addition to saving material and weight, this also improves maintenance, as the motor shaft can be easily separated from the rest of the system.

[0010] A fundamental aspect of the invention lies in connecting the gearbox to the motor via a plug-in shaft inserted into the hollow shaft of the motor shaft. The torque is thus transmitted from the motor to the gearbox via this plug-in shaft. Compared to previous drilling drive arrangements, a particularly compact arrangement of gearbox, motor shaft, and motor can be achieved by having the plug-in shaft extend directly from the gearbox into the motor shaft. The gearbox can therefore be positioned directly on the drive motor, and the motor shaft barely, or preferably not at all, protrudes from the motor housing. This reduces the axial length of the drilling drive arrangement. In addition to efficient power transmission, this allows for a longer installation length of the drill string and / or an extended axial travel distance of the drilling drive arrangement along a mast or drill rig.The smaller the axial extent of the drilling drive assembly in the direction of the drilling axis, the longer the installation length of a drill string and / or the axial travel distance of the drilling drive assembly along a mast or drill rig can be.

[0011] A preferred embodiment of the invention consists in the at least one drive motor and the gearbox being arranged on a drive carriage, which is designed with a linear guide by which the drive carriage can be moved along a guide of a mast or a drill rig. In drilling operation, a mast is essentially vertical, although a certain angle of inclination can be adjusted, while a drill rig can be largely freely adjustable in space by means of a generally known support arm mechanism. Such drill rigs are used in particular for anchor drilling with anchor drilling rigs. A linear guide is provided along the mast or drill rig, along which a drive carriage with the compact drilling drive assembly can be moved.The drive carriage allows the drilling drive arrangement to be precisely adjusted in a desired drilling direction, and the drilling drive arrangement according to the invention is particularly suitable for swiveling and adjusting movements due to its compact design.

[0012] It is particularly preferred that several drive motors with gearboxes are arranged, especially on the drive carriage. Two or more drive motors can be integrated into the drill drive assembly. A parallel shaft gearbox, particularly a spur gear or a planetary gearbox, can be used. The drive motors can preferably each individually drive a drill string and / or a drill bit. The drill string can be designed as a double-head drill string with an inner and an outer tube. It is advantageous if one drive motor is provided for rotating the inner tube and one for rotating the outer tube, whereby the inner and outer tubes can be driven in the same or, preferably, in opposite directions of rotation. The drive motors can, in principle, be arranged arbitrarily on the drive carriage, for example, axially one behind the other or, in particular, laterally next to each other.This allows for a particularly efficient drilling operation.

[0013] In principle, the drive motors can be designed in any configuration. According to the invention, a particularly reliable design is achieved by using an electric motor or a hydraulic motor, especially an axial piston motor. Preferably, a brushless electric motor can be used. The drive motor can additionally include a control unit, which is designed in particular for controlling speed and torque. This design of the drive motor allows the drilling drive assembly to be made smaller and more compact, which significantly facilitates operation in the often confined construction and working spaces, preferably on construction sites.

[0014] A further advantageous embodiment of the invention consists in the insertion space extending from a free end of the motor shaft to a region of the motor shaft located within the motor housing. The free end of the motor shaft can encompass the outer circumferential region and / or the axial end region of the motor shaft. It is advantageous if the insertion cross-section is rectangular or rounded, particularly circular. Likewise, the insertion cross-section can have teeth and / or locking corners, thereby ensuring a particularly secure connection to the insertion space in the free end of the motor shaft.

[0015] A further advantageous embodiment of the invention consists in the fact that the insertion shaft, which is inserted into the insertion space, is located predominantly within the motor housing. Preferably, the motor shaft does not protrude beyond the motor housing. The shaft connection is thus largely or completely located within the motor housing, resulting in a particularly compact design.

[0016] The insertion shaft can pass completely or partially through the drive motor. It can be particularly advantageous if the insertion shaft passes through at least half, preferably at least two-thirds, of the rotor of an electric drive motor during insertion. This ensures particularly efficient power transmission from the drive motor to the insertion shaft. Generally, the insertion shaft can be of any design. However, it is preferred if the insertion shaft also has at least one hollow body and is preferably designed as a hollow tube. It is advantageous if both the motor shaft and the insertion shaft are designed entirely as cylindrical hollow bodies for the passage of an inner tube. According to one embodiment of the invention, it is particularly advantageous if the insertion space is designed as a blind hole in the motor shaft.The motor shaft, particularly in the power generation area of ​​the motor, can be designed as a solid, and therefore especially stable, shaft. The inner surface of the insertion recess can preferably have elongated profiles, in particular a keyway profile. It is possible that the insertion shaft can be inserted into the insertion recess and locked in place with at least one rotational and / or longitudinal movement.

[0017] A preferred embodiment of the invention also consists in the at least first torque transmission element and the at least one second torque transmission element forming a torque-transmitting positive-lock connection. The torque transmission elements can be designed, in particular, as teeth, grooves, bolts, and / or projections and recesses, and engage with one another. The positive-lock connection can preferably be designed as a splined shaft, toothed shaft, keyway, or keyway connection. According to the invention, it is particularly preferred if the stub shaft is designed as the drive shaft. The stub shaft can preferably also be designed as a splined shaft or toothed shaft.

[0018] It is advantageous if the drive shaft has a serrated tooth profile on its outer circumference or a polygonal profile in its cross-section. This means that the drive shaft can also be designed as a polygonal connection. It is preferred if different types of torque transmission elements, such as polygons and teeth, are formed simultaneously.

[0019] It is particularly advantageous if at least one drive element, especially a key, is arranged on the insertion shaft. Alternatively or additionally, at least one drive element or a drive groove, especially a groove suitable for a key, can preferably be provided on the insertion recess for positive-locking force transmission. In addition to positive-locking connections, friction-locking connections and / or material-locking connections can also be used according to the invention, particularly as supplementary measures.

[0020] According to one embodiment of the invention, it is particularly advantageous that several first torque transmission elements and several second torque transmission elements are arranged, with a splined shaft connection formed between the insertion shaft and the motor shaft. This allows for easy insertion of the insertion shaft into the motor shaft. Furthermore, particularly high and fluctuating torques, as is common in drilling drives, can be transmitted.

[0021] According to a further development of the invention, it is advantageous to arrange a first drive motor with a first gearbox for driving an inner drill string and a second drive motor with a second gearbox for driving an outer drill string. It is particularly preferred if the drive motors are arranged axially one behind the other. It is especially advantageous if the inner and outer drill strings can be rotated in opposite directions. Depending on the type of application and soil conditions, this enables particularly efficient drilling.

[0022] According to the invention, a further development comprises a drilling rig with a carrier unit, which is particularly mobile, and a mast or carriage along which a drive carriage is slidably mounted, wherein a drilling drive arrangement according to the invention is arranged on the drive carriage. Due to the particularly compact arrangement of the motor and gearbox, the drilling depth and adjustability on the mast can be improved with the drilling rig according to the invention. Likewise, pivoting the drilling rig, for example during assembly or disassembly, is facilitated due to the reduced tipping moment.

[0023] The invention is explained in more detail below with reference to a preferred embodiment, which is shown schematically in the single drawing. The drawing according to Figure 1shows a schematic cross-sectional view of the drilling drive arrangement according to the invention with drive motor, gearbox and insertion shaft.

[0024] The in Figure 1The drill drive arrangement shown comprises a drive motor 14 with a gearbox 26. As illustrated here, a motor housing 18 can preferably be designed, which substantially encompasses or encloses the drive motor 14. The motor housing 18 can preferably form a housing unit completely or partially with the gearbox housing and be designed to accommodate the drive motor 14 and gearbox 26. The motor shaft 22 preferably does not protrude from the motor housing 18, or at most only protrudes slightly. The motor shaft 22 is set into a rotary motion during operation. The motor shaft 22 can preferably have a recess 38 with a rectangular or polygonal cross-section, into which, as shown here, a shaft 36 is preferably inserted. The force generated in the drive motor 14 is transmitted to the motor shaft 22 and from there, via the torque transmission elements 46 and 42, to a shaft 36.The transmission elements 42 of the inner insertion space 38 and the torque transmission elements 46 of the insertion shaft can preferably be arranged on opposite sides and / or offset.

[0025] As in Figure 1 As shown, the torque can preferably be transmitted by an insert shaft 36 inserted into the insertion space 38 of a hollow shaft 34 of the motor shaft 22 and from there directly to the gearbox 26. According to the invention, the insert shaft 36 can preferably have a coupling element for performing switching operations, wherein the coupling element is designed to disengage the drive motor 14 and gearbox 26. In this respect, the drilling drive arrangement 10 according to the invention can be configured in particular for switching operations and / or for adjusting the speed.

[0026] The transmission 26, as shown in the figure, preferably comprises a transmission input element 30 with at least one transmission gear 28, in particular a sun gear. The input shaft 36 can, in particular, form a single unit with the transmission gear 28. Generally, the transmission 26 can be configured as desired, but especially as a planetary gear, spur gear, bevel gear, or helical gear for adapting the rotational quantities, in particular the speed and torque, as required. In the transmission 26 shown as an example in the figure, the input and output shafts are aligned coaxially. However, the input and output shafts of the transmission 26 can preferably also be inclined at an angle or offset in parallel.The torque can be transmitted, as shown here, preferably via gears, in particular planetary gears, radially outward from the shaft 36 to the output gear element 32 and subsequently to an earth drilling tool or drill string. The output gear element 32 can in particular be designed as a shaft.

[0027] According to the drilling drive arrangement 10 according to the invention, the drive motor 14 and the gearbox 26 can preferably be located essentially directly adjacent to one another, as in the embodiment shown in the figure. The distance between the gearbox 26 and the drive motor 14 can preferably be less than 50 mm, and in particular less than 25 mm. A protective space can preferably be provided between the drive motor 24 and the gearbox 26, wherein the protective space is formed at least between the gearbox, the drive motor, and the drive shaft. This reduces the ingress of foreign objects and improves the thermal properties of the drilling drive arrangement 10.

Claims

1. Drilling drive arrangement (10) for driving an earth drilling tool, comprising: - at least one drive motor (14) with a motor housing (18) and a motor shaft (22), wherein a drive torque generated in the motor housing (18) can be transmitted via the motor shaft (22), and - a gearbox (26) which is connected downstream of the drive motor (14) and is designed to convert the drive torque, wherein the gearbox (26) comprises an input gearbox element (30) which receives the drive torque from the motor shaft (22) of the drive motor (14), and an output gearbox element (32) through which the drive torque converted by the gearbox (26) can be transmitted to the earth drilling tool or a drill string. characterized by that the motor shaft (22) of the drive motor (14) is at least partially designed as a hollow shaft (34) with an inner insertion space (38) on which at least one first torque transmission element (42) is formed, and thatthe input gear element (30) of the transmission (26) has a gear gear (28) with an insertion shaft (36) on which at least a second torque transmission element (46) is formed, wherein the insertion shaft (36) is detachably inserted axially into the inner insertion space (38) of the motor shaft (22) to form a rotationally fixed connection.

2. Drilling drive arrangement (10) according to claim 1, characterized by that the at least one drive motor (14) and the gearbox are arranged on a drive carriage which is designed with a linear guide with which the drive carriage can be moved along a guide of a mast or a drill carriage.

3. Drill drive arrangement (10) according to claim 1 or 2, characterized by that Several drive motors with gearboxes are arranged, particularly on the drive carriage.

4. Drill drive arrangement (10) according to one of claims 1 to 3, characterized by thatthe drive motor is designed as an electric motor or a hydraulic motor, in particular as an axial piston motor.

5. Drill drive arrangement (10) according to one of claims 1 to 4, characterized by that the insertion space (38) extends from a free end of the motor shaft (22) to a region of the motor shaft (22) which lies within the motor housing (18).

6. Drilling drive arrangement according to claim 5, characterized by that the insertion shaft (36) inserted into the insertion space (38) is located to a predominant extent within the motor housing (18).

7. Drilling drive arrangement according to one of claims 1 to 6, characterized by that the insertion space (38) is designed as a blind hole in the motor shaft (22).

8. Drilling drive arrangement (10) according to one of claims 1 to 7, characterized by thatthe at least first torque transmission element and the at least one second torque transmission element form a torque-transmitting positive locking connection.

9. Drill drive arrangement (10) according to one of claims 1 to 8, characterized by that several first torque transmission elements and several second torque transmission elements are arranged, with a keyway shaft connection formed between the insertion shaft and the motor shaft.

10. Drilling drive arrangement (10) according to one of claims 1 to 9, characterized by that a first drive motor with a first gearbox for driving an inner drill string and a second drive motor with a second gearbox for driving an outer drill string are arranged.

11. Drilling rig with a carrier unit, which is in particular designed to be movable, and a mast or carriage along which a drive carriage is slidably mounted, characterized by that a drilling drive arrangement according to one of claims 1 to 10 is arranged on the drive carriage.

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