Drilling drive device for land drilling equipment

Abstract

The present invention relates to a drilling drive device (10) for a land drilling device, which has a mandrel assembly. The mandrel assembly has an inner mandrel unit (20) and an outer mandrel unit (40). The outer mandrel unit is supported on the inner mandrel unit (20) in an axially displaceable manner and floats between two spring devices (50, 60). According to the present invention, it is provided that the first front spring device (50) arranged on the drilling tool side comprises a combination of at least one compression coil spring and a first disc spring assembly (54), and the second rear spring device (60) facing away from the drilling tool side has a second disc spring assembly (64).

Description

Technical Field

[0001] The present invention relates to a drilling drive device for a land drilling device according to the preamble of claim 1, having a mandrel assembly which has an inner mandrel unit and an outer mandrel unit, the outer mandrel unit being axially displaceably supported on the inner mandrel unit and floating between two spring devices. Background Art

[0002] Such drilling drive devices are known in particular from drilling equipment for land and rock drilling, in which a down-the-hole hammer drilling unit is used as a drilling tool. In the down-the-hole hammer drilling unit, one or more axially driven impact elements are provided which additionally perform an impact movement during the rotational drive of the down-the-hole hammer drilling unit. Such a down-the-hole hammer drilling unit can in particular be used for making drill holes in hard rock. For example, a down-the-hole hammer unit is known from EP3336301A1.

[0003] It is known that the additional impact movement performed in the down-the-hole hammer drilling unit results in an additional load being applied to the rotating drilling drive. To reduce this load, it is furthermore known that the drive mandrel of the drilling drive is supported in the axial direction in a spring-loaded manner to prevent the axial hammering from directly affecting the bearings of the drilling drive.

[0004] However, due to such a type of support, the further operation of the drive mandrel is affected. In particular, even when using a down-the-hole hammer drilling unit, a certain axial squeezing force must be applied during the drilling operation. In addition, a certain axial clearance must also be provided to allow axial screwing in the case of a drill pipe consisting of a plurality of drill bars with threaded connections. Summary of the Invention

[0005] It is an object of the present invention to provide a drilling drive device which on the one hand enables effective drilling operation when using an axially impacting drilling tool and on the other hand enables good protection of the drilling drive.

[0006] According to the present invention, this object is achieved by a drilling drive device having the features of claim 1. Preferred embodiments of the present invention are described in the dependent claims.

[0007] The drilling drive device according to the present invention is characterized in that the first front spring device arranged on the drilling tool side comprises a combination of at least one compression coil spring and a first disc spring assembly, and the second rear spring device facing away from the drilling tool side has a second disc spring assembly.

[0008] The basic concept of the present invention lies in that a floating bearing is provided between the outer mandrel unit and the inner mandrel unit and between two spring preloading devices. In particular, the first front spring device facing the side with the drilling tool and the second rear spring device facing away from the drilling tool side each have a disc spring assembly. Due to these two disc spring assemblies, the impact movement from the drilling tool, especially the down-the-hole hammer unit, can be absorbed and buffered particularly well. Therefore, the drilling tool can be connected to the inner mandrel unit or the outer mandrel unit according to the type of the assembly. Preferably, the torque is introduced via the outer mandrel unit, so that due to the lack of support, the impact of the inner mandrel unit cannot be transmitted or can only be transmitted to the outer mandrel unit in a strongly buffered manner. Conversely, the torque can also be first transmitted from the drilling drive to the inner mandrel unit, while the drilling tool is directly or connected to the outer mandrel unit via a drill pipe.

[0009] According to another aspect of the present invention, in addition to the first disc spring assembly, at least one compression coil spring is arranged on the first front spring device. Therefore, the relatively soft compression coil spring preferably particularly enables an easy relative displacement between the two mandrel units, which is advantageous, for example, when screwing on a drill pipe element with a threaded connection. In summary, an effective drilling operation can be achieved in this way, while the impact from the drilling tool to the drilling drive is well buffered.

[0010] A preferred embodiment of the present invention lies in that the compression coil spring of the first spring device is held on the one hand on a first radially outwardly directed flange on the outside of the inner mandrel unit and on the other hand on a bearing ring which is axially displaceably supported on the outer mandrel unit and is spring-loaded by the disc spring assembly. Since the compression coil spring is supported on the outside of the mandrel assembly, good mobility and simple maintenance of the components are ensured.

[0011] The flange on the outside can be designed integrally with the inner mandrel unit or can be fixed thereto.

[0012] Another suitable embodiment of the drilling drive device according to the present invention thus results in that the second disc spring assembly of the second rear spring device is held on the one hand on a second radially outwardly directed flange of the inner mandrel unit and on the other hand on the outer mandrel unit. Therefore, at least one of the radially outwardly directed flanges is mounted in a releasable manner. In summary, the spring assembly can be well mounted in this way.

[0013] According to an improvement of the present invention, a torque transmission device, in particular an axial spline shaft tooth part, is arranged. The torque transmission device is designed to transmit torque from the drive wheel of the drilling driver to the mandrel assembly. Therefore, the torque transmission device can be designed on the inner mandrel unit or the outer mandrel unit. Preferably, the torque transmission device is arranged between the front spring device and the rear spring device. In this way, overloading of the drilling driver caused by axial impacts during drilling operation is resisted.

[0014] Basically, the disc spring assembly can be designed arbitrarily. According to an improvement of the present invention, an embodiment that requires particularly little maintenance is obtained, that is, the first disc spring assembly and / or the second disc spring assembly is received in a receiving recess. Therefore, the receiving recess can be designed, in particular, on one of the flanges. The receiving recess is in particular an annular receiving groove.

[0015] According to another implementation variant of the drilling drive device according to the present invention, it is advantageous that a connecting device for mounting a drill rod element is provided on the front side of the inner mandrel unit. Therefore, in particular, a thread can be provided in the connecting device, and the mating thread area of the drill rod element is screwed onto this thread.

[0016] For effective drilling operation, it is particularly advantageous that the compression coil spring has a spring constant smaller than that of the first disc spring assembly and a spring deflection larger than that of the first disc spring assembly. In this way, the compression coil spring can in particular ensure the necessary axial clearance, which is desirable for mounting the drill rod element.

[0017] In combination with this, it is particularly advantageous that the spring deflection of the compression coil spring is equal to or greater than the thread length of the drill rod element with a connecting thread to be mounted.

[0018] To ensure a defined axial movement between the two mandrel units, according to an improvement of the present invention, it is appropriate that an annular guiding cutout is formed on the inner mandrel unit, and the sleeve-shaped guiding projection of the outer mandrel unit engages into this guiding cutout for cooperation. This ensures a guiding movement between the two mandrel units.

[0019] The present invention further includes a drilling device, in particular a land drilling device with at least one drilling driver, wherein the outer mandrel unit of the drilling drive device according to the present invention is driven by the drilling driver. Therefore, the drilling device can in particular be a pile drilling device for manufacturing foundation piles in the ground. For this purpose, any type of drilling tool can be used, such as a drilling auger, a continuous flight auger, a drill bucket, etc.

[0020] According to an improved embodiment, preferably, as a drilling tool, a down-the-hole hammer unit is mounted on a drill pipe, which can be driven in a rotational manner by means of a drilling drive device. Such a down-the-hole hammer unit is generally known from the prior art. The down-the-hole hammer unit has a base body, which is usually cylindrical and drives one or more hammer elements in an axially reversible manner on the lower side of the base body facing the ground. The axial drive of the hammer elements can be achieved in particular by supplying pressurized fluid, in particular compressed air. In order to supply pressurized fluid and drilling fluid and / or to discharge the drilling fluid with drill cuttings, the core shaft assembly, in particular the inner core shaft unit, can be designed tubularly with an internal cavity, and corresponding lines can be guided through the internal cavity. Description of the Drawings

[0021] The present invention will be further described below based on a preferred embodiment schematically shown in the drawings, wherein:

[0022] Figure 1 A schematic cross-sectional view of a drilling drive device according to the present invention is shown;

[0023] Figure 2 Shown according to Figure 1 An enlarged view of the left region of the drilling drive device; and

[0024] Figure 3 Shown according to Figure 1 An enlarged cross-sectional view of the right region of the drilling drive device. Detailed Description of the Invention

[0025] In Figures 1 to 3 The drilling drive device 10 according to the present invention shown therein generally consists of an inner core shaft unit 20 (which has a tubular base body 22 with an inner pipe 23) and a tubular outer core shaft unit 40 (which is coaxial with and surrounds the inner core shaft unit 20). Via an approximately central torque transmission device 70, torque is transmitted to the outer core shaft unit 40 and / or the inner core shaft unit 20 in a generally known manner via one or more (preferably hydraulically driven) drilling drives 5. The inner core shaft unit 20 extends rearward through the annular torque transmission device 70 and has a rotational feedthrough 12 at its rear end facing away from the drilling tool to transfer at least one fluid from an unshown drilling device to the inner pipe 23 of the tubular inner core shaft unit 20.

[0026] The rotating supply unit 12 generally has two main components, namely a rotor 14 (which is torsionally connected to the inner core shaft unit 20) and a stator 16 facing backward with respect to the rotor (which is held on the housing of the torque transmission device 70 via a torque support 18). The rotor 14 rotates relative to the stationary stator 16, and for example, fluid lines for conveying cleaning or drilling suspensions can be attached to the stator. The outer core shaft unit 40 rotates together with the inner core shaft unit 20, and the inner core shaft unit is supported in an axially displaceable manner relative to the outer core shaft unit 40.

[0027] On the front side of the inner core shaft unit 20 facing the drilling, a radially outwardly directed first flange 24 is arranged, and a drilling tool can be detachably fixed to the first flange directly or indirectly via a connecting device 25 and an installed drill rod element. The drilling tool can in particular be a down-the-hole hammer drilling unit, which has one or more axially driven impact elements.

[0028] In order to buffer the impact pulses of the down-the-hole hammer drilling unit onto the torque transmission device 70, the drilling drive device 10 is provided with a first spring device 50 and a second spring device 60, which will be described in more detail with reference to Figure 2 and Figure 3 more specifically.

[0029] The first spring device 50 has two spring components, namely a compression coil spring 52 and a first disc spring assembly 54. The compression coil spring 52 coaxial with the drilling axis thus holds forward on the first flange 24 on the tubular base body 22 of the inner core shaft unit 20 and on the other hand holds on a bearing ring 30.

[0030] The bearing ring 30 can have a first ring 31 and a second ring 32. Here, the first ring 31 is displaceably supported on the outside of the inner core shaft unit 20 and is held in a spring-loaded manner relative to the outer core shaft unit 40 by means of a coaxial first disc spring assembly 54, wherein a first pre-tightening force F TF is applied to the first ring 31 and thus to the bearing ring 30 by the first disc spring assembly 54. Via a radially protruding stop, the first ring 31 is connected to the second ring 32, and the other end of the compression coil spring 52 is held on the stepped step of the second ring, wherein via the compression coil spring 52, the pre-tightening force F DF is applied to the first flange 24 and thus to the inner core shaft unit 20.

[0031] The compression coil spring 52 achieves a stroke H1, which is significantly greater than the stroke H2 of the first disc spring assembly 54. Here, the compression coil spring 52 is preferably provided with a smaller spring constant than the first disc spring assembly 54. The stroke H1 can in particular be designed to compensate for the necessary thread pitch or screwing distance when screwing onto an additional drill pipe element. The stroke H2 of the first disc spring assembly 54 is preferably used to cushion the axial impacts that can be exerted by the drilling tool.

[0032] According to Figure 3 , the coaxial second spring device 60 only has a second disc spring assembly 64, which is held on the shoulder of the outer mandrel unit 40 on the one hand and on the second flange 28 on the other hand, which is releasably fixed (more specifically screwed) to the outside of the tubular base body 22 of the inner mandrel unit 20. A second receiving recess 66 is formed by means of a retaining ring 42 on the outer mandrel unit 40, in which the disc springs of the second disc spring assembly 60 are arranged in a protected manner. Via the second disc spring assembly 60, a pre-tensioning force F TFZ can be transmitted from the outer mandrel unit 40 to the inner mandrel unit 20, and this second disc spring assembly can also be used to cushion the axial forces of the down-the-hole hammer drilling unit. When the inner mandrel unit 20 is axially displaced to the right, the retaining ring 42 keeps the disc spring 60 in a pre-tensioned state.

[0033] To ensure guidance, an annular guiding cutout 34 can be arranged on the outside of the tubular base body 22, into which a corresponding guiding projection 44 of the outer mandrel unit 40 engages.

Claims

1. A drilling drive device for a land drilling equipment, which has a mandrel assembly. The mandrel assembly has an inner mandrel unit and an outer mandrel unit. The outer mandrel unit is supported on the inner mandrel unit in an axially displaceable manner and floats between two spring devices. wherein, - The first front spring device arranged on the side of the drilling tool includes a combination of at least one compression coil spring and a first disc spring assembly, and - The second rear spring device facing away from the side of the drilling tool has a second disc spring assembly.

2. The drilling drive device according to claim 1, wherein, The compression coil spring of the first front spring device is held on the one hand on a radially outwardly directed first flange on the outside of the inner mandrel unit and on the other hand on a bearing ring which is axially displaceably supported on the outer mandrel unit and is spring-loaded by the first disc spring assembly.

3. The drilling drive device according to claim 1, wherein, The second disc spring assembly of the second rear spring device is held on the one hand on a radially outwardly directed second flange of the inner mandrel unit and on the other hand on the outer mandrel unit.

4. The drilling drive device according to claim 1, wherein, A torque transmission device is arranged.

5. The drilling drive device according to claim 1, wherein, An axial spline shaft tooth part is arranged.

6. The drilling drive device according to claim 1, wherein, The first disc spring assembly and / or the second disc spring assembly are received in a receiving recess.

7. The drilling drive device according to claim 1, wherein, On the front side of the inner mandrel unit, a connecting device for mounting a drill pipe element is provided.

8. The drilling drive device according to claim 1, wherein, The compression coil spring has a spring constant smaller than that of the first disc spring assembly and a spring deflection larger than that of the first disc spring assembly.

9. The drilling drive device according to claim 8, wherein, The spring deflection of the compression coil spring is equal to or greater than the thread length of the drill pipe element with a connection thread to be installed.

10. The drilling drive device according to claim 1, wherein, An annular guiding cutout is formed in the inner mandrel unit, and a sleeve-shaped guiding projection of the outer mandrel unit engages into the guiding cutout for mating.

11. A drilling equipment, which has at least one drilling driver, wherein, Driven by the drilling driver (5) The outer mandrel unit of the drilling drive device according to claim 1.

12. The drilling equipment according to claim 11, wherein, The drilling equipment is a land drilling equipment.

13. The drilling device according to claim 11, wherein, As a drilling tool, a down-the-hole hammer unit is mounted on a drill pipe which can be driven in a rotational manner by means of the drilling drive device.

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