Drilling robot

Abstract

The invention relates to a drilling robot for drilling holes. The drilling robot (2) is purely electrically driven and comprises a moving unit for moving the drilling robot through the hole and a rotating hammer unit having a drill bit (21), a rotating system (22) and a hammering system (23). The rotation system (22) is adapted to rotate the drill bit (21) and the hammering system (23) is adapted to hammer with the drill bit (21). The hammering system (23) is adapted to operate according to the electro-pneumatic principle to generate an electro-pneumatic strike.

Description

Technical Field

[0001] The present invention relates to a drilling robot for drilling boreholes. The drilling robot is purely electrically driven. It includes a moving unit for moving the drilling robot through the borehole and a rotary hammer unit. The rotary hammer unit includes a drill bit, a rotation system, and a hammering system. The rotation system is adapted to rotate the drill bit. The hammering system is adapted to hammer with the drill bit. Background Art

[0002] Generating heat from geothermal energy plays a crucial role in the successful thermal transformation worldwide. Traditionally, pneumatic hammers are used to drill boreholes for geothermal probes, where a compressor and a drill rig are configured outside the borehole, and the drilling energy is transmitted via a drill pipe to the drill bit inside the borehole. The drill cuttings are flushed out of the borehole. As the depth of the borehole increases, the pressure drop of the compressed air along the drill pipe increases significantly. A very large compressor is required to generate the necessary pressure and flow rate.

[0003] Such a drilling system requires a large amount of space. The energy-intensive, expensive, and inaccurate process results in noise and serious damage to the landscape. As a result, many buildings cannot benefit from geothermal heat or are equipped with other heating systems. Summary of the Invention

[0004] Therefore, the problem to be solved by the present invention is to provide a compact drilling robot for drilling boreholes that can operate with low energy consumption.

[0005] This problem is solved by a drilling robot according to the independent claims. Accordingly, the purely electrically driven drilling robot includes a moving unit and a rotary hammer unit having a drill bit, a rotation system, and a hammering system. The moving unit moves inside the borehole and stabilizes the drilling robot. The rotation system is adapted to rotate the drill bit. The hammering system is adapted to hammer with the drill bit and operates according to the electro-pneumatic principle to generate an electro-pneumatic stroke. In particular, the hammering system includes a piston that compresses and expands the air between itself and a counterweight, especially a cylindrical counterweight, especially without contacting the counterweight.

[0006] The advantages of such a drilling robot are that the drill rig is directly located in the borehole and does not require a drill pipe or other large equipment. Due to the autonomous and energy-saving mode of operation, the construction cost is significantly reduced. The purely electrically driven drilling robot does not cause uncomfortable noise.

[0007] Advantageously, the drilling robot includes at least one electric motor, especially two electric motors. In particular, the first of the at least one electric motor drives the rotation system, and the second of the at least two electric motors drives the hammering system.

[0008] The first electric motor generates torque and can have a power of about 0.6 kW or more, in particular greater than 1 kW. The second electric motor generates impacts and can have a power of about 0.95 kW. The impact energy generated breaks the rock.

[0009] In particular, the drilling robot has a cylindrical shape with a diameter of less than 250 mm, in particular less than 200 mm, in particular less than 150 mm, in particular less than 100 mm, in particular less than 90 mm. Compared with today's drilling equipment, much less material has to be processed. Drilling such small holes is energy-saving and low-cost.

[0010] Advantageously, no part of the drilling robot protrudes from the cylindrical shape. That is, the diameter of the cylindrical shape defines the diameter of the hole. For example, if the diameter of the drilling robot is 80 mm, the resulting hole has a diameter of about 90 mm.

[0011] Advantageously, the first electric motor and the second electric motor are arranged within the cylindrical shape. All the power of the drilling robot is generated within the compact cylindrical shape. The drilling robot moves through the hole like a worm.

[0012] In particular, the first electric motor is further away from the drill bit than the second motor. That is, the power of the rotation system is generated further away from the drill bit than the power of the hammering system. Only when the electric motors are arranged in a row can a compact drilling robot be achieved. The torque generated by the first electric motor is transmitted from the first electric motor to the drill bit via a bypass shaft, which is arranged on one side of the second electric motor in the longitudinal direction, in particular parallel to the second electric motor. This results in a compact drilling robot with an optimized relationship between the size and power of the drilling robot.

[0013] Advantageously, the bypass shaft rotates at a frequency that is 30%, in particular 50%, in particular 100%, in particular 120% higher than the rotational frequency of the first electric motor. In other words, after it bypasses the second electric motor, i.e., between the second electric motor and the drill bit, the high rotational speed of the first electric motor is only substantially converted into a lower rotational speed with a higher torque. The advantage of bypassing the second electric motor with a high rotational speed is that the size of the bypass shaft can be set to have a small diameter. This is an aspect that needs to be taken into consideration because the sizes of both the second electric motor and the bypass shaft determine the diameter of the drilling robot.

[0014] Preferably, the drill bit includes a reamer that rotates at a frequency that is at least 10 times lower, particularly 20 times lower, than the rotational frequency of the first electric motor. This frequency conversion is achieved by a gearbox disposed between the drill bit and the second electric motor, and the gearbox provides frequency conversion for the rotational system with a conversion coefficient of at least 8, particularly at least 10, particularly at least 20, particularly at least 40.

[0015] Advantageously, the rotational system includes an epicyclic gear train (i.e., a planetary gear set) or a cycloidal drive. In particular, the epicyclic gear train or the cycloidal drive is disposed between the drill bit and the second electric motor.

[0016] In a preferred embodiment, the hammering system generates impacts, and the impacts travel through the sun gear of the epicyclic gear train to the drill bit. This design has the advantage of an optimal sizing and configuration of the electric motor and the gearbox. In an efficient manner, the impacts can be transmitted from the second electric motor to the drill bit, and the power of the rotational system can be converted into a low rotational speed with high torque.

[0017] In particular, the hammering system includes a piston that compresses and expands the air between the piston and the cylindrical counterweight without contacting the cylindrical counterweight.

[0018] In other preferred embodiments, the drilling robot includes a water-based flushing system for flushing drill cuttings from the drill bit to the surface of the borehole.

[0019] The drill cuttings can be separated from the water by a special filtration system, and the water is reused for flushing. In particular, a sensor detects the water level, which allows water to be added or removed.

[0020] Advantageously, the hammering unit is adapted to operate with a hammering energy of at least 0.08 J / mm, particularly at least 0.1 J / mm, particularly 0.12 J / mm, relative to the diameter of the drilling robot shaped like a cylinder. For example, if the hammer unit operates with a hammering energy of 11 J and the drilling robot shaped like a cylinder has a diameter of 80 mm, then a relationship of 0.1375 J / mm is obtained.

[0021] Other advantageous embodiments are listed in the dependent claims and the following description. Description of the Drawings

[0022] The present invention will be better understood from the following detailed description of the invention, and objects other than those set forth above will become apparent. This description refers to the accompanying drawings, in which:

[0023] Figure 1 A general illustration of a system for drilling a borehole is shown;

[0024] Figure 2Shows an overview of a drilling robot operating inside a borehole;

[0025] Figure 3a The drilling robot is shown from the outside;

[0026] Figure 3b Shows Figure 3a the drilling robot, where the housing of the drilling robot is not shown;

[0027] Figure 3c Shows a cross-sectional view of the drilling robot. Detailed Description

[0028] The following is a description of the detailed implementation. The technical data given is only exemplary and does not limit the scope of the claims.

[0029] Figure 1 Shows a single-family house and the equipment for drilling borehole 1. Borehole 1 was drilled to heat the house by geothermal energy. The drilling equipment includes a drilling robot 2 that operates autonomously inside borehole 1. That is, the drill rig is directly located in borehole 1 and does not require drill pipes. The drilling robot 2 is connected to a power source and a water source via a connector 3. A container 4 is arranged on the surface 5 for collecting drill cuttings from the drilling robot 2. The drilling robot can drill boreholes for geothermal detectors to a depth of at least 250 meters or a maximum of 500 meters.

[0030] Figure 2 Shows the drilling robot 2 operating inside borehole 1 in a more detailed view. The drilling robot 2 includes a drilling unit 3, a moving unit 4, and a control unit 5. In addition, a support system (not shown in detail) is arranged inside borehole 1 following the drilling robot 2.

[0031] The moving unit 4 moves the drilling robot 2 through borehole 1. During drilling, the moving unit 4 clamps against the drill wall 6 of borehole 1 to absorb all the forces of the drilling process. The control unit 5 controls the drilling process of the drilling robot 2 and transmits information to the operating user at the surface 5. The support system supports the drill wall 6. Especially in loose rock without a support system, rocks, sand, clay, etc. will fall into the borehole and cause it to collapse. The support system prevents this.

[0032] The water-based flushing system 8 efficiently flushes the drill cuttings 9 to the surface 5. The water-based flushing system 8 is connected to a water source 10. The flushing is done by a pump 11 that can generate a volume flow of about 5 m 3 / h at a pressure of 15 bar. Then, the water is pumped to the surface 5.

[0033] The water-based flushing system 8 separates the drill cuttings 9 from the water through a special filtration system 12, which reuses the water for flushing. The separated drill cuttings 9 are stored in the container 4. Sensors detect the water level, which allows for the addition or removal of water.

[0034] The drilling robot 2 is purely electrically driven and powered by a power supply 13. In addition, the drilling robot 2 has a cylindrical shape with a diameter D1 of 80 mm, and the borehole 1 has a diameter D2 of 90 mm.

[0035] Figure 3a The drilling robot 2 is shown from the outside, while Figure 3b the drilling robot 2 is shown without the housing 20 of the drilling robot 2 being sealed. Figure 3c A cross-sectional view of the drilling robot 2 is shown.

[0036] The drilling robot 2 includes a rotary hammer unit having a drill bit 21, a rotary system 22, and a hammering system 23. The drill bit 21 is designed as an overburden system and includes a pilot bit 25 and three reamers 26. The drill bit 21 is rotated by the rotary system 22. The drill bit 21 is responsible for breaking the rock and removing the drill cuttings 9 beneath the drill bit 21. Thus, space is made for the drilling robot 2 to advance in depth. The rotary hammer unit including the drill bit 21 is designed such that it can operate in different rock formations by changing the rotary and hammering motions.

[0037] The rotary system 22 includes a water-cooled first and upper electric motor 27. The first electric motor 27 provides the torque required to rotate the drill bit 21 through a plurality of cylindrical gear pairs 28, a bypass shaft 29, and a planetary gear set 30 (also known as an epicyclic gear train). Then, a sliding clutch 31 transmits the power to the main shaft 32.

[0038] The first electric motor 27 rotates at a speed of 3 k rpm and operates at a power of 0.6 kW. The cylindrical gear pair 28 converts the rotation of the electric motor 27 into a higher rotational speed, which is further transmitted to the main shaft 32 through the bypass shaft 29. In other words, the bypass shaft 29 rotates at a frequency higher than 100% of the rotational frequency of the first electric motor 27. The planetary gear set 30, which is part of the gearbox of the rotary system, together with the cylindrical gear pair 36 configured between the drill bit 21 and the second electric motor 31, significantly reduces the rotational speed such that the reamer 26 operates at a rotational speed of approximately 100 rpm and a corresponding torque. The reamer 26 rotates at a frequency 30 times lower than the first electric motor 27 and 40 times lower than the bypass shaft 29.

[0039] The hammering system 23 includes a second and lower electric motor 31. The second electric motor 31 is at a shorter distance from the drill bit 21 than the first electric motor 27. The second electric motor 31 powers a piston 32 driven by bevel gears 35. The piston 32 compresses and expands the air 33 between itself and a cylindrical counterweight 34, but does not contact the cylindrical counterweight 34. The cylindrical counterweight 34 moved by the air 33 impacts the spindle 32 several times per second with its kinetic energy, thereby providing blows traveling downward to the drill bit 21. This principle is called electro-pneumatic hammering. The spindle 32 extends through the sun gear 33 of the planetary gear set 30.

[0040] The second electric motor 31 rotates at a speed of approximately 13 k rpm and operates at a power of approximately 0.7 kW. The rotational speed is reduced by bevel gears 22 such that the piston operates at approximately 2.5 k rpm.

[0041] Finally, the drill bit 21 operates with a torque of 57 Nm, a rotational speed of 100 rpm, a hammering energy of 11 J, and 2.5 k blows per minute.

[0042] The bypass shaft 29 that transfers the torque from the first electric motor 27 to the drill bit 21 is arranged longitudinally in the direction 37 on one side of the second electric motor 31, particularly parallel to the second electric motor 31.

[0043] Under impact, the rotary and translational feedthrough of the water-based flushing system 8 comes into play. It allows water to enter the central flushing channel 8 of the spindle 32. Then the water travels downward to the drill bit 21.

[0044] The housing 20 consists of multiple components that are sealed against external pressure and held together by metal strips.

Claims

1. A drilling robot (2) for drilling a borehole (1), wherein the drilling robot (2) is purely electrically driven and comprises: - a moving unit (4) for moving and stabilizing the drilling robot (2) within the borehole (1), - a rotary hammer unit having a drill bit (21), a rotary system (22) and a hammering system (23), wherein the rotary system (22) is adapted to rotate the drill bit (21), and wherein the hammering system (23) is adapted to hammer with the drill bit (21), characterized in that the hammering system (23) is adapted to operate according to an electro-pneumatic principle to generate an electro-pneumatic impact.

2. The drilling robot (2) according to claim 1, wherein the drilling robot (2) comprises at least one electric motor (27, 31), in particular two electric motors (27, 31).

3. The drilling robot (2) according to claim 2, wherein a first electric motor (27) of the at least one electric motor (27, 31) drives the rotary system (22), and a second electric motor (31) of the at least one electric motor (27, 31) drives the hammering system (23).

4. The drilling robot (2) according to any one of the preceding claims, wherein the drilling robot (2) has a cylindrical shape with a diameter (D1) of less than 250 mm, in particular less than 200 mm, in particular less than 150 mm, in particular less than 100 mm, in particular less than 90 mm.

5. The drilling robot (2) according to claims 3 and 4, wherein the first electric motor (27) and the second electric motor (31) are arranged within the cylindrical shape.

6. The drilling robot (2) according to claim 3 and according to any one of the preceding claims, wherein the first electric motor (27) is further away from the drill bit (21) than the second electric motor (31).

7. The drilling robot (2) according to claim 6, wherein the torque generated by the first electric motor (27) is transmitted from the first electric motor (27) to the drill bit (21) via a bypass shaft (29), the bypass shaft (29) being arranged on one side of the second electric motor (31) in a longitudinal direction, in particular parallel to the second electric motor (31).

8. The drilling robot (2) according to claim 7, wherein the bypass shaft (29) rotates at a frequency that is 30%, in particular 50%, in particular 100% higher than the rotational frequency of the first electric motor (27).

9. The drilling robot (2) according to claim 3 and according to any one of the preceding claims, wherein the drill bit (21) comprises a reamer (26) that rotates at a frequency that is at least 10 times lower, in particular 20 times lower, than the rotational frequency of the first electric motor (27).

10. The drilling robot (2) according to claim 3 and according to any one of the preceding claims, wherein the gearbox configured between the drill bit (21) and the second electric motor (31) of the percussion system (23) of the rotation system (22) provides frequency conversion for the rotation system (22) with a conversion factor of at least 8, in particular at least 10, in particular at least 20, in particular at least 40.

11. The drilling robot (2) according to any one of the preceding claims, wherein the rotation system (22), in particular the gearbox according to claim 10, comprises an epicyclic gear train (30) or a cycloid drive.

12. The drilling robot (2) according to claim 3 and according to claim 11, wherein the epicyclic gear train (30) or the cycloid drive is configured between the drill bit (26) and the second electric motor (31).

13. The drilling robot (2) according to claim 11 or according to claim 12, wherein the percussion system (23) generates impacts, and wherein the impacts travel to the drill bit (21) through the sun gear (33) of the epicyclic gear train (30).

14. The drilling robot (2) according to any one of the preceding claims, wherein the percussion system (23) comprises a piston (32) that compresses and expands the air (33) between the piston (32) and the cylindrical counterweight (34) without contacting the cylindrical counterweight (34).

15. The drilling robot (2) according to any one of the preceding claims, comprising a water-based flushing system (8) for flushing the drill cuttings to the surface (5).

16. The drilling robot (2) according to any one of the preceding claims, wherein the percussion system (23) is adapted to operate with a percussion energy of at least 0.08 J / mm, in particular at least 0.1 J / mm, in particular 0.12 J / mm, relative to the diameter (D1) of the drilling robot (2) shaped like a cylinder.

17. The drilling robot (2) according to any one of the preceding claims, wherein the drill bit (21) is adapted to operate with a torque of at least 0.35 Nm / mm, in particular at least 0.62 Nm / mm, relative to the diameter (D1) of the drilling robot (2) shaped like a cylinder.

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