DRILL DRIVE ARRANGEMENT

Description

The invention relates to a drill drive arrangement for driving an earth drilling tool, having 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 by the motor shaft, and having a transmission which is downstream of the drive motor and is configured to convert the drive torque, wherein the transmission comprises an input transmission element which receives the drive torque from the motor shaft of the drive motor and an output transmission element by which the drive torque converted by the transmission can be transmitted to the earth drilling tool or a drill string, according to the preamble of claim 1.

A drill drive arrangement is usually located at one end of a drill string distal to the borehole and can be moved along a mast, as is known from DE 32 47 202 C1, for example. For static reasons alone a compact structural form is desirable for drill drive arrangements.

A known drill drive arrangement can be found, for example, in DE 199 06 687 B4. The device taught there is a drilling rig for producing boreholes with two separately operable drive motors, which transmit a torque to an inner pipe or an outer pipe via a transmission. To transmit power from the motor to the transmission, the drive motor has a motor shaft protruding from the motor housing, onto which an insertion shaft with pinion or a gear pinion is directly attached, in particular screwed on. The drilling rig comprises yet further gearwheels with which the torque is transmitted from the respective gear pinion to the outer pipe or the inner pipe.

DE 44 02 487 A1 describes 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 pipe or an outer pipe. The complex structure consisting of several drives and gearwheels is in this case prone to errors and requires a high level of maintenance. The arrangement of at least one motor at the side of the pipe also leads to increased space requirements in the side area.

DE 197 04 263 C1 also discloses a drilling rig in which a rotary drive with an output shaft directly drives a rod and drives another rod via a transmission. The drives, which are configured as hydraulic motors, have a motor shaft protruding from a drive housing, on which a coupling is arranged, which forms a connection to the actual drill drive shaft.

The object of the invention is to provide a drill drive arrangement which enables particularly efficient use for driving an earth drilling tool.

The object is achieved by a device with the features of claim 1. Preferred embodiments of the invention are stated in the dependent claims.

The device according to the invention for driving an earth drilling tool is characterised in that the motor shaft of the drive motor is at least partially configured as a hollow shaft with an inner insertion space on which at least one first torque transmission element is formed, and in that the input transmission element of the transmission has a gearwheel with an insertion shaft on which at least one second torque transmission element is formed, wherein the insertion shaft is releasably inserted axially into the inner insertion space of the motor shaft in a matched manner to form a torque proof connection.

A basic idea of the invention can be seen in the fact that the motor shaft, which is at least partially configured as a hollow shaft, simplifies the power transmission and makes it more efficient. By forming a hollow space in the motor shaft, the torque of the drive can be transmitted particularly reliably and efficiently by introducing an insertion shaft despite reduced assembly effort. In contrast to previous drill drive arrangements, the frictionally engaged connection to continuative parts is thus carried out within the motor shaft of the drive motor. In addition to material and weight savings, this improves the maintenance, as the motor shaft is particularly easy to separate from the rest of the system.

A basic idea of the invention can also be seen in that to connect the transmission to the motor via an insertion shaft, which is inserted into the hollow shaft of the motor shaft. The torque is therefore transmitted from the motor to the transmission via the insertion shaft. Compared to previous drill drive arrangements, a particularly compact arrangement of transmission, motor shaft and motor can be achieved in that the insertion shaft extending from the transmission directly into the motor shaft. The transmission can therefore be arranged directly on the drive motor and the motor shaft hardly needs to protrude from the motor housing, or preferably not at all. This shortens the axial installation length of the drill drive arrangement. In addition to a favourable power transmission, thus an increased installation length of a drill string and/or an extended axial travel path of the drill drive arrangement along a mast or a drill carriage mount can be achieved. Because the smaller an axial extent of the drill drive arrangement in the direction of the drill axis is, the longer a installation length of a drill string and/or an axial travel path of the drill drive arrangement along a mast or a drill mount can be.

A preferred embodiment of the invention lies in the fact that the at least one drive motor and the transmission are arranged on a drive carriage, which is configured with a linear guide with which the drive carriage can be slided along a guide of a mast or a drill carriage mount. In a drilling operation, a mast is substantially vertical, wherein a certain angle of inclination can be adjustable, while a drill mount can be adjusted largely freely in space by means of a basically known support arm mechanism. Such drill carriage mounts are used in particular for anchor drilling in anchor drilling rigs. A linear guide is formed along the mast or the drill mount, along which linear guide a drive carriage with the compact drill drive arrangement can be slided. The drive carriage can be used to precisely adjust the drill drive arrangement in a desired drilling direction, wherein the drill drive arrangement according to the invention is particularly suitable for swivelling and adjusting movements due to its compact arrangement.

It is particularly preferable that several drive motors with transmissions are arranged, in particular on the drive carriage. Two or more drive motors can be formed on the drill drive arrangement. A parallel shaft transmission, in particular a spur transmission or a planetary transmission, can be used as the transmission. The drive motors can preferably each individually drive a drill pipe and/or a drilling tool. For this, the drill pipe can be configured as a double-headed drill pipe with an inner and an outer pipe. It is useful if respectively a drive motor is provided for rotating the inner and outer pipes, wherein the inner and outer pipes can be driven in the same or preferably in opposite directions of rotation. In principle, the drive motors can be arranged anywhere on the drive carriage, for example axially one behind the other or, in particular, side by side. This enables a particularly efficient drilling operation to be achieved.

In principle, the drive motors can be of any design. According to the invention, a particularly reliable construction is achieved in that the drive motor being configured as an electric motor or a hydraulic motor, in particular as an axial piston motor. Preferably, a brushless electric motor can be used. The drive motor can also have a control unit, which is configured in particular to control the speed and torque. By designing the drive motor in this way, the drill drive arrangement can be designed smaller and more compact, which significantly facilitates operation in often confined construction and operating spaces, preferably construction sites.

A further advantageous embodiment of the invention resides in that the insertion space extends from a free end of the motor shaft up to an area of the motor shaft which lies within the motor housing. The free end of the motor shaft can thereby comprise the outer circumferential area and/or the axial end area of the motor shaft. It is advantageous if the insertion cross-section is formed rectangular or roundish, in particular circular. The insertion cross-section can also have serrations and/or securing corners, with what a particularly secure connection to the insertion space in the free end of the motor shaft is ensured.

A further advantageous embodiment of the invention resides in that the insertion shaft inserted into the insertion chamber is located for a most part inside the motor housing. Preferably, the motor shaft does not protrude from the motor housing. The shaft connection is therefore located largely or completely inside the motor housing, which results in a particularly compact structural form.

The insertion shaft can pass completely or partially through the drive motor. It can be particularly expedient if the insertion shaft passes through at least half, preferably at least two-thirds, of a rotor of an electric drive motor during insertion. This ensures particularly efficient power transmission from the drive motor to the insertion shaft. In general, the insertion shaft can be formed arbitrarily. However, it is preferable if the insertion shaft also has at least one hollow body and is preferably configured as a hollow pipe. It is advantageous if both the motor shaft and the insertion shaft are completely configured as a cylindrical hollow body for the passage of an inner pipe.

According to one variant of the invention, it is particularly advantageous for the insertion chamber to be formed as a blind hole in the motor shaft. In this way, the motor shaft can be configured as a massive and therefore particularly stable solid shaft, particularly in the area of force generation in the motor. The inner surface of the insertion chamber can preferably have elongate profiles, in particular a keyway profile. It is possible that the insertion shaft can be inserted into the insertion chamber and can be locked with at least one rotational and/or longitudinal movement.

A preferred embodiment of the invention is also that the at least first torque transmission element and the at least one second torque transmission element form a torque-transmitting form-fit connection. In particular, the torque transmission elements can be configured for this purpose as teeth, grooves, bolts and/or projections and recesses and can engage with one another. The form-fit connection can preferably be configured as a splined shaft connection, serrated shaft joint, feather key joint or matched joint. According to the invention, it is particularly preferable if the insertion shaft is configured as a drive shaft. The insertion shaft can preferably also be configured as a splined shaft or toothed shaft.

It is advantageous if the insertion shaft has a serration on the outer circumference or a polygonal profile in cross-section. This means that the insertion shaft-drive shaft can also be configured as a polygonal connection. It is preferable in this case if different types of torque transmission elements such as polygons and teeth are formed at the same time.

It is particularly useful if at least one driver element, in particular a feather key, is arranged on the insertion shaft. Alternatively or in addition to this, the insertion chamber can preferably have at least one driver element or a driver groove, in particular a groove matching a feather key, for form-fit force transmission. In addition to form-fit connections, frictionally engaged connections and/or substance-bonded connections can also be used according to the invention, in particular as a supplement.

According to one variant of the invention, it is particularly advantageous that several first torque transmission elements and several second torque transmission elements are arranged, wherein a splined shaft connection is formed between the insertion shaft and the motor shaft. This enables simple insertion of the insertion shaft into the motor shaft. It is also possible in this case to transmit particularly large and alternating torques, as is usual in the field of drill drives.

According to a further development of the invention, it is advantageous that a first drive motor with a first transmission for driving an inner drill pipe and a second drive motor with a second transmission for driving an outer drill pipe are arranged. It is particularly preferable in this case if the drive motors are arranged axially one behind the other. It is particularly advantageous if the inner and outer drill rods can be rotated in opposite directions. Depending on the type of application and ground conditions, this enables particularly efficient drilling.

According to the invention, an expedient development consists in a drilling rig with a carrier device therein, which is configured in particular to be movable and has a mast or a carriage mount, along which a drive carriage is slideably mounted, wherein a drill drive arrangement according to the invention is arranged on the drive carriage. With the drilling rig according to the invention, the drilling depth and the adjustability on the mast can be improved due to the particularly compact arrangement of the motor and transmission. It is also facilitated to swivel the drilling rig, for example during assembly and disassembly, due to the lower tilting moment.

The invention is explained in greater detail below with reference to a preferred exemplary embodiment, which is shown schematically in the sole drawing. The drawing according to the FIGURE shows a schematic cross-sectional view of the drill drive arrangement according to the invention with drive motor, transmission and insertion shaft.

The drill drive arrangement shown in the FIGURE has a drive motor 14 with a transmission 26. As shown here, a motor housing 18 can preferably be formed, which substantially encloses or houses the drive motor 14. The motor housing 18 can preferably form a housing unit, either completely or partially, with the transmission housing and can be configured to accommodate the drive motor 14 and transmission 26. In this case, the motor shaft 22 preferably does not protrude, or at the most protrudes slightly, from the motor housing 18. The motor shaft 22 is set in a rotary motion during operation. The motor shaft 22 can preferably have an insertion chamber 38 which is rectangular or polygonal in cross-section and in which, as shown here, an insertion 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 an insertion shaft 36. Transmission elements 42 of the inner insertion chamber 38 and the torque transmission elements 46 of the insertion shaft can in this case preferably be arranged on opposite sides and/or offset.

As shown in the FIGURE, the torque can preferably be transmitted by an insertion shaft 36 inserted into the insertion space 38 of a hollow shaft 34 of the motor shaft 22 and from there be transmitted directly to the transmission 26. According to the invention, the insertion shaft 36 can preferably have a coupling element for carrying out shifting operations, wherein the coupling element is configured to disengage the drive motor 14 and the transmission 26. In this respect, the drill drive arrangement 10 according to the invention can be configured in particular for shifting operations and/or for adjusting the speed.

As shown in the FIGURE, the transmission 26 can preferably have a transmission input element 30 with at least one transmission gearwheel 28, in particular a sun gear. In particular, the insertion shaft 36 can in this case form a unit with the transmission gearwheel 28. In general, the transmission 26 can be of any configuration, but in particular as a planetary transmission, spur transmission, bevel wheel transmission and helical wheel transmission for adapting the rotational variables, in particular the rotational speed and torque, as required. In the transmission 26 shown as an example in the FIGURE, the input and output axles are aligned coaxially. However, the input and output axles of the transmission 26 can preferably also be inclined at an angle or offset in parallel. As shown here, the torque can in this case preferably be transmitted to the output transmission element 32 and then to an earth drilling tool or a drill string via external gears, in particular planetary gears, radially to the insertion shaft 36. The output transmission element 32 can in this case in particular be configured as a shaft.

According to the drill drive arrangement 10 according to the invention, the drive motor 14 and the transmission 26 can preferably be substantially directly adjacent to one another, as in the exemplary embodiment shown in the FIGURE. The distance between the transmission 26 and the drive motor 14 can in this case preferably go below 50 mm, in particular 25 mm. A protective space can preferably be provided between the drive motor 24 and transmission 26, wherein the protective space is formed at least between the transmission, drive motor and drive shaft. This can reduce the ingress of foreign bodies and improve the thermal properties of the drill drive arrangement 10.