DRILL

Description

[0001] The present invention relates to a drilling rig, in particular in the form of a Kelly drilling rig, with a drill tool holder for receiving a drill rod, in particular a Kelly rod, which can be driven rotaryally by a drilling drive via a gearbox, wherein the gearbox comprises a gearbox housing with several gearbox elements rotatably mounted therein.

[0002] Various drilling methods are used in specialist foundation engineering to create boreholes in the ground. The resulting cavity can be used to produce a variety of products, such as cast-in-place concrete piles by filling them with fresh concrete, or precast concrete and steel elements that then serve as load-bearing or retaining structures. These drilling methods include double-head drilling, grab drilling, full displacement drilling, continuous auger drilling, and Kelly drilling. Kelly drilling is one of the most common dry rotary drilling methods, suitable for almost all soil and rock types, and named after its drill string, the so-called Kelly bar. This telescopic Kelly bar allows for very great drilling depths.

[0003] In Kelly drilling, drill rods are guided through a gearbox with a hollow shaft, through which the torque is built up, whereby the gearbox together with the drive and the drill tool holder can usually be moved up and down on a mast to achieve the feed rate.

[0004] The individual drill rods, which can be several meters long and weigh several tons, are telescopically constructed in the Kelly drilling method and can be locked together, with the locking mechanism being similar to a bayonet fitting. The drill rods are attached at one end to a cable and are driven rotaryally by the drill drive. The feed is achieved by moving the drill table, on which the drive, gearbox, and drill bit holder are mounted, along the drill guide.

[0005] However, when locking the drill rods, the locking mechanism frequently fails to engage, causing the drill rods to fall vertically from a considerable height, their own weight bearing down on the drill gearbox. This accelerates the drill gearbox downwards. The gearbox components not axially fixed within the gearbox, however, remain stationary due to their inertia, potentially resulting in shock loads on individual components. For example, the motor shaft can strike the stationary gearbox shaft, which, if the drill gearbox is a planetary gearbox or includes a planetary stage, could be the sun gear shaft.Such sudden impacts repeatedly cause damage to the interior of the gearbox, especially to the gearbox components, raising the question afterwards of whether the breakage of a gearbox component was caused by an inadequate gearbox design, a defective component, or by such an excessive impact from a falling drill rod.

[0006] The problem described is not limited to Kelly drilling rigs, but can also occur with other drilling equipment whose drill tool holder is driven rotaryally via a gearbox and is exposed to shock-like, external loads in rough drilling operations.

[0007] A drilling table that can be moved along a mast and carries a drilling drive and gearbox for a Kelly bar is known, for example, from German patent application DE 20 2013 100 548 U1. Further Kelly drilling rigs are shown in German patent applications KR 2011 013 76 95 A, DE 12 16 218 B, DE 196 26 223 C2, DE 10 2012 019 850 A1, DE 10 2008 037 338 A1 and DE 10 2015 105 908 A1.

[0008] The present invention is based on the objective of creating an improved drilling device of the aforementioned type, which avoids disadvantages of the prior art and advantageously develops the latter further. In particular, the gear elements of the gearbox are to be better protected against impact loads and, if such damage nevertheless occurs, its cause is to be traceable.

[0009] According to the invention, the aforementioned problem is solved by a drilling device according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

[0010] It is therefore proposed to protect impact-prone transmission elements against shock loads by means of an internal transmission shock absorber. The shock absorber is designed such that it undergoes permanent deformation under excessive impact loads, making such excessive impacts detectable and indicating them even after the fact. The shock absorber can elastically cushion smaller impact loads, while impact loads exceeding a certain threshold, which pose a risk of damage to the shock-damped transmission element, lead to plastic deformation of the shock absorber. According to the invention, at least one plastically deformable shock absorber element is provided to absorb impacts on at least one of the transmission elements within the transmission housing.

[0011] The aforementioned shock absorber can in particular be assigned to a mass-bearing, non-positionally fixed transmission element in order to cushion inertial shocks when parts falling onto the transmission from the outside cause the transmission to shake, so to speak.

[0012] According to the invention, the shock absorber is designed to absorb axial shocks in the direction of the axis of rotation of the at least one transmission element to which the shock absorber is assigned, and then deforms plastically when the axial shock force exceeds a predetermined threshold. This threshold is advantageously below the destruction limit, preferably also below a damage limit, at which the shock-absorbed transmission element would be destroyed or damaged, so that the shock absorber deforms plastically or permanently even upon axial impacts without destroying or damaging the shock-absorbed transmission element.

[0013] Due to the plastic deformability of the shock absorber, which produces a permanent deformation of the shock absorber when impact forces exceed the aforementioned threshold, the gearbox manufacturer, for example, can subsequently reliably assess whether a defective gearbox was exposed to excessive shock loads.

[0014] Advantageously, the shock absorber in question can be a component designed separately from normal bearing elements, which performs no bearing functions, or at least no permanent bearing functions, and merely provides additional support in the event of an impact. In particular, the shock absorber can be positioned at a distance from the transmission element to be shock-absorbed in its undeformed initial state. Thus, in its initial state, the shock absorber is without contact with the transmission element to be shock-absorbed. Such clearance between the shock absorber and the transmission element does not impair the normal transmission function and, in particular, does not generate any additional frictional resistance.The shock absorber only becomes active and only comes into contact with the transmission element to be shock-absorbed when this element experiences a displacement and / or shift and / or deformation due to a larger shock load, which deviates from the normal movement of the transmission element in non-shock-loaded operation.

[0015] The shock absorber can be designed in various ways. In an advantageous embodiment of the invention, the shock absorber can be designed as an at least approximately flat damper disc or as a flat damper plate, which may have an inner and / or outer edge that is plastically deformable. In principle, such a damper disc or damper plate can also deform plastically in a central ring area or even across its entire body when a corresponding shock load is introduced into the shock absorber. Such a disc-, plate-, or plate-shaped design of the shock absorber requires little space and adds little additional weight to the transmission, which can therefore be designed to be space-saving and lightweight.

[0016] In an advantageous further development of the invention, the shock absorber can be arranged coaxially to a central transmission shaft and / or extend essentially transversely to the axis of rotation of the transmission element to be absorbed.

[0017] If the shock absorber is designed as a damping disc or plate as described above, the disc or plate diameter can be at least five or even ten times larger than the disc or plate thickness, defined as the material or wall thickness of the disc or plate body. This thin or thin-walled design gives the damper sufficient elasticity to absorb smaller or limited impacts, while also allowing the desired plastic deformation to occur in the event of larger impacts. At the same time, the damper is lightweight and compact.

[0018] In particular, the shock absorber can be designed in the form of a thin steel disc. However, other materials can also be used for the shock absorber.

[0019] In a further development of the invention, the shock absorber can support a transmission shaft against the transmission housing under shock loads, in particular to prevent the transmission shaft from striking a motor shaft under shock loads due to its inertia.

[0020] The support of the transmission shaft can be achieved in various ways. In a further development of the invention, the shock absorber can be arranged between the transmission shaft and a motor drive shaft that is non-rotatably connected to it, and can support and absorb shocks from the transmission and / or motor shaft to a transmission housing and / or to the motor housing or to a structural component rigidly connected to the motor and / or transmission housing.

[0021] To prevent the transmission and engine shafts from striking each other, the shock absorber, especially when designed as a damper disc or plate with a collar, can surround the transmission shaft and / or engine shaft and be arranged between a shaft shoulder and / or end face of the engine shaft and a shaft shoulder and / or end face of the transmission shaft, so that the transmission shaft and / or engine shaft, in the event of axial displacement due to shock loads, so to speak, gets caught on or hits the collar and the shock absorber can exert its shock-absorbing effect.

[0022] Such a shock absorber with a collar on the transmission shaft can be particularly advantageous if the transmission shaft is arranged to be axially displaceable and rotationally fixed, for example by a hub / shaft profile connection.

[0023] There are various advantageous designs for arranging the shock absorber. For example, the shock absorber can be firmly supported on the gearbox housing and / or on the adjoining drive motor housing and / or a structural component rigidly connected to it, in particular it can be rigidly attached to it, for example by detachable fasteners such as a screw connection.

[0024] As an alternative to a rigid mounting of the shock absorber, it can also be mounted in a floating manner and / or rotate with a gear element.

[0025] In particular, the shock absorber can be attached to a rotary transmission element in order to rotate with this transmission element, whereby the said transmission element does not have to be - but may nevertheless be - the transmission element which is shock-damped by the shock absorber.

[0026] If the transmission includes, for example, a planetary stage, the shock absorber can be attached to a planet carrier and positioned between a transmission shaft shoulder and / or end face on the one hand and a housing shoulder and / or end face on the other, so that the shock absorber supports the said transmission shaft against the housing shoulder or end face in the event of axial impacts.

[0027] In the neutral initial state, the shock absorber can be positioned at a distance from both the aforementioned transmission shaft and the housing in order to avoid generating frictional resistance when the shock absorber rotates with the planet carrier.

[0028] The invention is explained in more detail below with reference to preferred embodiments and accompanying drawings. The drawings show: Fig. 1: A schematic overall view of a drilling rig in the form of a so-called Kelly drilling rig according to an advantageous embodiment of the invention; Fig. 2: A sectional view of the drill tool holder with the drill rod that can be inserted therein, as well as the gearbox with which the drill tool holder can be driven rotaryally by a drive motor; Fig. 3: A partial sectional view of the gearbox made of Fig. 2 , which shows a damper disc between a transmission input shaft and the motor drive shaft according to an advantageous embodiment of the invention, and Fig. 4: a partial sectional view of the transmission similarly Fig. 3 , wherein a damper disc is attached to a planet carrier of the gearbox and is positioned between a gearbox shaft shoulder and a housing shoulder.

[0029] How Fig. 1 As shown, the drilling rig can be designed in the form of a Kelly drilling rig, although it is understood that this is only one advantageous design and the drilling rig can also implement other drilling methods or be designed for other drilling methods.

[0030] How Fig. 1 As shown, the drilling device 1 can have a drill guide in the form of a mast 2, along which a drill carriage 3 can be moved to achieve the feed of the drilling tool 4. For example, the drill carriage 3 can be moved along the mast 2 by a cable drive 5, although a feed cylinder or another feed drive can also be provided.

[0031] The aforementioned drill leader 2 can be mounted so that it can tilt around a horizontal axis, enabling not only vertical but also inclined drilling. Independently of this, the drill leader 2 can be mounted on the superstructure of a mobile drilling vehicle, which may, for example, be a tracked vehicle. The superstructure can be rotated around a vertical axis relative to the chassis.

[0032] How Fig. 1 As further shown, a drill drive 6 can be mounted on the drill carriage 3 in order to drive a drill rod 7 with a cutting or drilling tool 4 attached to it in a rotary motion, so that the movement of the drilling tool is composed on the one hand of the rotary motion generated by the drill drive and on the other hand of the feed motion by moving the drill carriage 3.

[0033] The drill rod 7 mentioned above can be a so-called Kelly bar, which consists of several drill rod sections that can be telescopically extended or retracted into each other.

[0034] The drill rod 7 can be suspended from the gallows 8 of the jig 2 via a rope, in particular a Kelly rope, in order to be pulled upwards through the drill carriage 3 and lowered.

[0035] How Fig. 2 As shown, the drill drive 6 on the drill carriage 3 includes a drill tool holder 9, which can be designed as a sleeve through which the drill rod 7 can be pushed longitudinally. The drill tool holder 9 and the drill rod 7 can each be provided with a torque-transmitting, positive-locking longitudinal profile to transmit a rotary drive movement from the tool holder 9 to the drill rod 7. For example, the drill rod 7 can have longitudinal grooves 10 into which the tool holder 9 engages with projecting longitudinal ribs 11. This arrangement can also be reversed, i.e., with projecting longitudinal ribs on the rod and longitudinal grooves in the sleeve-shaped holder, or other torque-transmitting profiles can be provided.

[0036] How Fig. 2 As further shown, the drill tool holder 9, which can be rotatably mounted on the drill carriage 3, can be driven via a gearbox 12, to which a drive motor 13 (shown only partially) can be coupled or connected on the input side. The aforementioned drive motor 13 can, for example, be a hydraulic motor or an electric motor.

[0037] How Fig. 2 As shown, the aforementioned transmission 12 can comprise a transmission housing 14 in which several transmission elements are rotatably mounted, wherein the aforementioned transmission elements can advantageously rotate about axes of rotation that extend parallel to the longitudinal axis of the boring bar 7. Depending on the transmission design, transmission elements with axes of rotation tilted relative to the longitudinal axis, for example helical gears or bevel gears, could also be provided.

[0038] In particular, the aforementioned transmission 12 can be designed as a planetary transmission and / or include at least one planetary gear stage, although a multi-stage planetary transmission can also be provided.

[0039] As the Figuren 3 and 4 As shown, for example, a planetary gear stage can be provided, the sun gear 15 of which can be non-rotatably connected to a gear input shaft 16, which can extend parallel to the longitudinal axis of the boring bar 7. The aforementioned sun gear can be in rolling mesh with planet gears 17, which are rotatably mounted on a planet carrier 18 and are also in rolling mesh with a ring gear 19.

[0040] If the planetary gear is designed to be multi-stage, for example the planet carrier 18 mentioned above can drive another sun gear of another planetary stage, which in turn is in rolling engagement with planet gears that are rotatably mounted on a planet carrier of the second stage and are in rolling engagement with a ring gear.

[0041] How Fig. 2 As shown, a gearbox output shaft can drive the aforementioned drill tool holder 9, for example via a spur gear stage.

[0042] However, it is understood that the configuration of the transmission elements can vary, and the output stage can also be designed differently. Depending on the desired gear ratio, the ring gear could also be connected to the transmission output shaft and / or function as the transmission input shaft, in which case the sun gear could then also serve as the output shaft.

[0043] How Fig. 3 To clarify, a shock absorber 20 is assigned to the aforementioned transmission input shaft 16, which may comprise or consist of a substantially flat damping disc 21.

[0044] The damper disc 21 mentioned above can be essentially flat and rigidly attached to the gearbox housing 14, for example by screwing it on.

[0045] The damper disc 21 mentioned above extends coaxially to the transmission input shaft 16 in a plane essentially perpendicular to its longitudinal axis.

[0046] Independently of this, the damper disc 21 can have a central recess, the circumferential edge of which forms a collar 22 that extends between the shaft shoulders 23 and 24 of the transmission input shaft 16 and / or overlaps the aforementioned shaft shoulders 23, so that the transmission input shaft 16 would bear against the collar 22 of the damper disc 21 during axial movements.

[0047] For example, if a heavy part such as the boring bar 7 falls onto the gearbox 12 from above, the gearbox is displaced downwards. However, due to its inertia, the gearbox input shaft 16 moves upwards or remains stationary within the gearbox housing 14 and does not follow the downward movement of the rest of the gearbox. In principle, the gearbox input shaft 16 would thus strike the motor shaft 25 axially, but this is prevented or at least cushioned by the aforementioned damper disc 21. Smaller impact loads can be absorbed by the shock absorber 20, while larger impact loads lead to plastic deformation of the collar 22 of the damper disc 21 or even to plastic deformation of the entire damper disc 21. This makes it possible to determine, even retrospectively, whether the gearbox has been subjected to significant impacts.

[0048] How Fig. 3 As shown, the aforementioned gearbox input and motor shafts 16 and 25 can, for example, be connected to each other in a rotationally fixed manner by a hub / shaft profile, but be axially displaceable relative to each other.

[0049] How Fig. 4 As shown, alternatively or additionally to a damper disc between the transmission input shaft 16 and the motor shaft 25, a damper disc 21 can also be provided between a transmission shaft, in particular the aforementioned transmission input shaft 16, and the transmission housing 14 in order to absorb shock loads and the resulting displacements of the transmission shaft on the transmission housing. In particular, such a damper disc 21 can be, cf. Fig. 4 , be attached to a rotating gear element, for example in the form of the aforementioned planet carrier 18, for example by a screw connection, so that the damper disc 21 rotates with the gear element.

[0050] The damper disc 21 can cover a shaft shoulder 23 of the aforementioned transmission shaft 16 with an inner collar 22 and a housing shoulder 27 of the transmission housing 14 with an outer collar 26, wherein the shaft shoulder 23 and the housing shoulder 27 can be located on opposite sides of the damper disc 21, cf. Fig. 4 .

[0051] Advantageously, the damper disc 21 is spaced away from both the shaft shoulder 23 and the housing shoulder 27 in its undeformed initial state, or arranged with clearance to them, so that the damper disc 21 can rotate with the planet carrier 18 without rubbing against the transmission input shaft 16 or the housing 14.

[0052] If the gearbox 12 is subjected to an axial shock load, which leads to a displacement of the gearbox input shaft 16 within or relative to the gearbox housing 14, the shaft shoulder 23 engages with the damper disc 21, which then presses against the housing shoulder 27 to absorb the shock. In the case of an excessive shock, the damper disc 21 deforms plastically to subsequently indicate and make such an excessive shock recognizable.

[0053] In an alternative embodiment of the invention, such a damper disc 21 could also be assigned to other transmission elements, for example the transmission output shaft and / or a transmission intermediate shaft.

[0054] Is the damper disc 21 in the Fig. 4As shown, the damper disc 21 is attached to the planet carrier 18. It can not only absorb shock loads on the transmission input shaft 16, but also prevent excessive displacement of the planet carrier 18. For example, if the planet carrier 18 is displaced upwards as a result of a shock load, the damper disc 21 dampens this by contacting the housing shoulder 27. In multi-stage planetary gears, the lower planetary stage components, which experience axial displacements, can also be absorbed by the housing shoulder 27. Conversely, downward displacements of the planet carrier 18 are absorbed by the shaft shoulder 23. Depending on the gear arrangement, the aforementioned directions "top" and "bottom" can be reversed or modified accordingly.

Claims

1. A drilling apparatus, in particular a Kelly drilling system, having a drilling tool receptacle (9) for receiving a drill rod (7), in particular a Kelly bar, which can be driven in rotation by a drilling drive (6) via a transmission (12), the transmission (12) comprising a transmission housing (14) with several transmission elements rotatably mounted therein, characterized in that at least one plastically deformable shock absorber (20) is provided to absorb shocks on at least one of the transmission elements in the transmission housing (14), and is configured to absorb axial shocks in the direction of the axis of rotation of the at least one transmission element to which the shock absorber (20) is assigned, and to plastically deform when the axial shock exceeds a predetermined threshold value.

2. The drilling apparatus according to the preceding claim, wherein the shock absorber (20) is arranged at a distance from the transmission element whose shocks it is intended to dampen in the undeformed initial state.

3. The drilling apparatus according to any one of the preceding claims, wherein the shock absorber (20) comprises a flat damper disc (21) or a flat damper plate having an inner edge and / or an outer edge deformable in an appropriate manner.

4. The drilling apparatus according to the preceding claim, wherein the damper disc or the damper plate is formed as a thin steel disc or thin steel plate whose outer diameter is at least five times or at least ten times greater than the material thickness of the disc or plate.

5. The drilling apparatus according to any one of the preceding claims, wherein the shock absorber (20) is arranged coaxially with a central transmission shaft (16) or extends essentially transversely to the axis of rotation of the element to be damped.

6. The drilling apparatus according to any one of the preceding claims, wherein the shock absorber (20) supports a transmission shaft (16) with respect to the transmission housing (14) in the event of shocks.

7. The drilling apparatus according to any one of the preceding claims, wherein the shock absorber (20) is arranged between a transmission input shaft (16) and a motor drive shaft (25) rotationally fixed thereto, and absorbs shocks of the transmission input shaft (16) and / or of the motor drive shaft (25) with respect to the transmission housing (14) and / or with respect to the motor housing (28).

8. The drilling apparatus according to the preceding claim, wherein the shock absorber (20) is fastened to the transmission housing (14).

9. The drilling apparatus according to any one of the preceding claims, wherein the or another shock absorber (20) is fastened to a planet carrier (18) and is arranged between a shoulder (23) and / or a shaft end face on the one hand and a shoulder (27) and / or a housing end face on the other hand, such that the shock absorber (20) absorbs axial shocks of the transmission shaft (16) on the transmission housing (14).

10. The drilling apparatus according to the preceding claim, wherein, in the undeformed initial state, the shock absorber (20) is spaced from both the transmission shaft (16) and the housing (14).

11. The drilling apparatus according to any one of the preceding claims, wherein the transmission (12) is arranged on a drill carriage (3) which is mounted so as to be longitudinally displaceable on a drill guide, in particular in the form of a leader (2), and which can be driven by a crowd drive along the longitudinal displacement path.

12. The drilling apparatus according to any one of the preceding claims, wherein the drill rod (7) is formed as a telescopic Kelly bar with several drill rod parts that can be pushed into one another and extended.

13. The drilling apparatus according to any one of the preceding claims, wherein the shock absorber (20) is associated with a transmission element that is not axially fixed or not fixed without axial play, and limits axial movements of this transmission element along its axis of rotation.