Differential drilling rock-breaking tool

Abstract

The application discloses a differential drilling rock breaking tool, which comprises a power part, a transmission part and a cutting part, the transmission part comprises an outer sun gear, an inner sun gear and a plurality of planetary gears, the inner sun gear is connected with the power part; the cutting part comprises a center drill bit and a planetary drill bit which is arranged in one-to-one correspondence with the planetary gears. When the power part drives the inner sun gear to rotate, the inner sun gear drives the center drill bit to make a clockwise or counterclockwise rotation movement, the planetary gears drive the planetary drill bit to make a rotation movement in the opposite direction of the center drill bit and a revolution movement in the same direction of the center drill bit, thereby forming a composite rotation movement of the center drill bit and the planetary drill bit to form an alternating movement cutting track. The application belongs to the category of realizing the cross track cutting of the drill bit by relying on the movement law of itself, and the geological conditions have little influence on the downhole drilling, and the movement of the drill bit body and the realization mode of the cross track cutting are stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and in particular to a differential drilling rock breaking tool. Background Technology

[0002] The PDC drill bit, assembled with drilling equipment, is a drilling rock-breaking tool with technical advantages such as high drilling safety, flexible structural design, and efficient rock breaking through shearing. Conventional fixed-cutting-tooth PDC drill bits move in a circular trajectory at the bottom of the well, with each tooth performing a scraping motion along its own fixed rotational path (i.e., concentric circles). This fixed cutting method often makes it difficult for the drill bit to penetrate hard, dense, or highly plastic formations, severely impacting its rock-breaking efficiency, especially in deep, difficult-to-drill formations. Summary of the Invention

[0003] The purpose of this application is to provide a differential drilling rock breaking tool to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this application provides the following technical solution: A differential drilling rock breaking tool, comprising: Power Department; The transmission unit includes an outer sun gear, an inner sun gear, and a plurality of planet gears constituting a planetary gear train structure. The outer sun gear is fixedly connected to the housing of the power unit, and the inner sun gear is connected to the power unit. The cutting section includes a central drill bit and planetary drill bits that correspond one-to-one with the planetary gears. The central drill bit is located at the lower end of the inner sun gear and moves synchronously with the inner sun gear. The planetary drill bits are located at the lower end of the planetary gears and move synchronously with the corresponding planetary gears. The central drill bit and the planetary drill bits are respectively provided with cutting teeth.

[0005] Furthermore, the cutting teeth of the central drill bit include external teeth and gauge-maintaining teeth. Multiple sets of external teeth are radially disposed on the lower end face of the central drill bit, and the gauge-maintaining teeth are disposed on the sidewall of the central drill bit along the extension path of the external teeth.

[0006] Furthermore, the cutting teeth of the central drill bit also include core teeth, which are located in the middle of the lower end face of the central drill bit.

[0007] Furthermore, the central drill bit is also provided with a nozzle, which is located near the center of the central drill bit and avoids the planetary drill bit.

[0008] Furthermore, the planetary drill bit adopts a blade-type PDC drill bit, and the cutting teeth of the central drill bit are arranged in the opposite direction to the cutting teeth of the planetary drill bit.

[0009] Furthermore, the upper end of the planetary gear is provided with an upper planetary carrier, the upper end of the planetary gear is connected to the upper planetary carrier through a bearing, and the lower end of the planetary gear is connected to the central drill bit through a bearing.

[0010] Furthermore, the central drill bit is provided with multiple through holes for mounting the planetary drill bit, the upper end of the planetary drill bit extends into the through holes and is threadedly connected to the lower end of the planetary gear, and a bearing is provided inside the through holes.

[0011] Furthermore, the bearing between the upper end of the planetary gear and the upper planet carrier is a radial bearing.

[0012] Furthermore, the power unit includes a universal joint assembly and a motor assembly, the upper end of the inner sun gear is threadedly connected to the lower connector of the universal joint assembly, and the lower end of the inner sun gear is threadedly connected to the upper end of the center drill bit.

[0013] Furthermore, the transmission unit is assembled into the housing of the motor assembly, and the outer sun gear is splined to the inner wall of the housing.

[0014] In summary, the technical effects and advantages of this invention are as follows: 1. This invention relies on its own motion laws to achieve the cross-trajectory cutting of the center drill bit and the planetary drill bit. When drilling downhole, geological conditions have little impact on it. Therefore, the motion of the center drill bit and the planetary drill bit and the realization of the cross-trajectory cutting are stable and reliable. 2. The cutting part of the present invention includes both the cutting teeth on the planetary drill bit that are fixedly connected to the planetary gear and the cutting teeth on the central drill bit. Both are on the same cutting profile, which helps to increase the cutting area during operation, thereby improving drilling and rock breaking efficiency. 3. In this invention, the central drill bit rotates in the opposite direction to the planetary drill bit. By rationally arranging the cutting parts, a torque balance effect can be achieved, thereby reducing the torque input of the drill string and significantly improving rock breaking efficiency. 4. When the present invention is in operation, the central drill bit and the planetary drill bit move in a non-eccentric manner, the cutting teeth have good symmetry in contact with the rock, and the resulting lateral unbalanced force is relatively small, which is conducive to the stable operation of the central drill bit and the planetary drill bit and extends the service life of the drill bit and the overall mechanism. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the differential drilling rock breaking tool in Embodiment 1 of the present invention; Figure 2 This is a simplified diagram of the mechanism motion of the differential drilling rock breaking tool in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the transmission unit in Embodiment 1 of the present invention; Figure 4 This is an assembly diagram of the transmission unit in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram showing the distribution of cutting teeth in the cutting part of Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the cutting part in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the structure of the central drill bit in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the planetary drill bit in Embodiment 1 of the present invention; Figure 9 This is the first cutting trajectory diagram in Embodiment 2 of the present invention; Figure 10 This is the second cutting trajectory diagram in Embodiment 2 of the present invention; Figure 11 This is the first cutting trajectory diagram in Embodiment 3 of the present invention; Figure 12 This is the second cutting trajectory diagram in Embodiment 3 of the present invention; Figure 13 This is the first cutting trajectory diagram in Embodiment 4 of the present invention; Figure 14 This is the second cutting trajectory diagram in Embodiment 4 of the present invention; Figure 15 This is a schematic diagram of the transmission unit in Embodiment 5 of the present invention; Figure 16 This is a schematic diagram of the cutting part in Embodiment 5 of the present invention.

[0017] The components are as follows: 1. Power unit; 11. Universal joint assembly; 12. Motor assembly; 2. Transmission unit; 21. Outer sun gear; 22. Planetary gear; 23. Inner sun gear; 3. Cutting unit; 31. Center drill bit; 31a. Core tooth; 31b. External tooth; 31c. Gauge protection tooth; 32. Planetary drill bit; 41. Upper planetary carrier; 5. Radial bearing; 6. Housing; 7. Lower connector; 8. Nozzle. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1

[0023] This embodiment provides a differential drilling rock breaking tool, such as... Figure 1-8As shown, the system includes a power unit 1, a transmission unit 2, and a cutting unit 3. The power unit 1 provides the driving force for the cutting unit 3, while the transmission unit 2 synchronously transmits the driving force to the cutting unit 3. The cutting unit 3 is used for drilling and rock breaking. Specifically, the transmission unit 2 includes an outer sun gear 21, an inner sun gear 23, and multiple planetary gears 22, forming a planetary gear train structure. The outer sun gear 21 is fixedly connected to the outer casing 6 of the power unit 1, and the inner sun gear 23 is connected to the power unit 1. The cutting unit 3 includes a central drill bit 31 and planetary drill bits 32 corresponding to each planetary gear 22. The central drill bit 31 is located at the lower end of the inner sun gear 23 and moves synchronously with it. The planetary drill bits 32 are located at the lower ends of the planetary gears 22 and move synchronously with their corresponding planetary gears 22. Both the central drill bit 31 and the planetary drill bits 32 have cutting teeth.

[0024] When the power unit 1 drives the inner sun gear 23 to rotate clockwise or counterclockwise, the planetary gear 22 undergoes two dynamic movements: one is a rotational motion driven by the inner sun gear 23 in the opposite direction to its own rotation, and the other is a revolution around the inner sun gear 23 in the same direction as its rotation. The central drill bit 31 moves synchronously with the inner sun gear 23, and the planetary drill bit 32 moves synchronously with the planetary gear 22. That is, the two types of drill bits in the cutting unit 3 form a composite rotational motion that is independent yet partially linked, and create an alternating motion cutting trajectory. This eliminates the fixed cutting method of the traditional approach, allowing the drill bit to perform a good cutting process under more complex and difficult working conditions, thereby improving rock breaking efficiency and quality.

[0025] Specifically, the cutting teeth of the central drill bit 31 include core teeth 31a, outer teeth 31b, and gauge-maintaining teeth 31c. The core teeth 31a are located in the middle of the lower end face of the central drill bit 31. Multiple sets of outer teeth 31b are radially arranged on the lower end face of the central drill bit 31, and the gauge-maintaining teeth 31c are located on the sidewall of the central drill bit 31 along the extension path of the outer teeth 31b. In this embodiment, the tooth structures of the core teeth 31a, outer teeth 31b, and gauge-maintaining teeth 31c form different cutting trajectories during the cutting process, thereby ensuring rock-breaking efficiency.

[0026] Furthermore, the central drill bit 31 is also equipped with nozzles 8, which are positioned near the center of the central drill bit 31 and avoid the planetary drill bit 32. In this technical solution, nozzles 8 are positioned near the center of the central drill bit 31 to promptly spray cooling liquid onto the central drill bit 31 and planetary drill bit 32 during rock breaking. Multiple sets of nozzles 8 are used, and adjustments and optimizations are made according to actual working conditions, such as selecting 2, 3, or 4 sets. In addition, the number of planetary gears 22 and planetary drill bits 32 can also be selected and adjusted in the same manner, without specific limitations. In this embodiment, there are 3 planetary gears 22 and 32 planetary drill bits. There are 3 nozzles 8, which are staggered with the planetary drill bits 32 in the circumferential direction.

[0027] In this preferred embodiment, the outer teeth 31b and gauge-maintaining teeth 31c of the central drill bit 31 are radially distributed on the outer side of the nozzle 8 along the centerline of the nozzle 8, while the core teeth 31a are disposed on the inner side of the nozzle 8. The diameter of the core teeth 31a disposed on the inner side of the nozzle 8 is smaller than the diameter of the outer teeth 31b and gauge-maintaining teeth 31c disposed on the outer side of the nozzle 8. Since the inner sun gear 23 is externally connected to the central drill bit 31, when the inner sun gear 23 is driven by the motor assembly 12 to rotate counterclockwise, the central drill bit 31 body is also driven to rotate counterclockwise. In this embodiment, the cutting teeth on the central drill bit 31 are arranged counterclockwise.

[0028] Furthermore, the planetary drill bit 32 adopts a blade-type PDC drill bit, which is a common structure in the prior art. The cutting teeth of the central drill bit 31 are arranged in the opposite direction to those of the planetary drill bit 32, thereby enabling the cutting part 3 to have cutting forces in multiple different directions during operation, thus improving rock breaking efficiency and quality. In this embodiment, the planetary drill bit 32 has cutting teeth arranged on the blades, and the arrangement direction of the cutting teeth is clockwise. Preferably, the planetary drill bit 32 in this embodiment is a solid structural component with high strength and is not prone to failure.

[0029] Specifically, the power unit 1 comprises at least a universal joint assembly 11 and a motor assembly 12. The motor assembly 12 provides driving force. One end of the universal joint assembly 11 is connected to the motor assembly 12, and the other end is connected to the inner sun gear 23, synchronizing the driving force provided by the motor assembly 12 to the inner sun gear 23. Optionally, the upper end of the inner sun gear 23 is threadedly connected to the lower connector 7 of the universal joint assembly 11, and the lower end of the inner sun gear 23 is threadedly connected to the upper end of the central drill bit 31. In this technical solution, the power structure, as described above, can be composed of the motor assembly 12 and the universal joint assembly 11. Its connection methods with other structures are detailed above and will not be repeated here.

[0030] Furthermore, the transmission unit 2 is assembled into the housing 6 of the motor assembly 12, and the outer sun gear 21 is splinedly connected to the inner wall of the housing 6. Specifically, the outer sun gear 21 has an external spline on its exterior, and the housing 6 has an internal spline on its interior; both are fitted using a spline shaft and a spline sleeve. This not only allows for positioning during assembly but also provides alignment during movement, ensuring that the outer sun gear 21 rotates under the drive of the housing 6, i.e., the outer sun gear 21 moves synchronously with the housing 6.

[0031] Furthermore, an upper planetary carrier 41 is provided at the upper end of the planetary gear 22. The upper end of the planetary gear 22 is connected to the upper planetary carrier 41 via a bearing, and the lower end of the planetary gear 22 is connected to the central drill bit 31 via a bearing. It should be noted that in this embodiment, the central drill bit 31 has cutting teeth at its lower end as a cutting structure for rock breaking. Furthermore, the central drill bit 31 can also be used as a lower planetary carrier to support the lower end of the planetary gear 22 and the planetary drill bit 32. That is, the lower planetary carrier and the central drill bit 31 are the same part, thus working with the upper planetary carrier 41 to achieve the straightening effect of the planetary gear 22, thereby optimizing the structure and reducing the complexity caused by structural stacking. The specific structure of the upper planetary carrier 41 is described in the prior art of planetary gear devices and will not be elaborated here. The upper end of the upper planetary carrier 41 is positioned by the step of the lower connector 7 of the universal joint assembly 11, and the lower end of the upper planetary carrier 41 is positioned by the step of the inner sun gear 23, thereby achieving axial positioning of the upper planetary carrier 41.

[0032] Furthermore, the central drill bit 31 is provided with multiple through holes for mounting the planetary drill bit 32. The upper end of the planetary drill bit 32 extends into the through holes and is threadedly connected to the lower end of the planetary gear 22. A bearing is provided inside the through holes. The lower end of the planetary gear 22 can pass through the bearing and connect to the planetary drill bit 32.

[0033] Furthermore, the bearing between the upper end of the planetary gear 22 and the upper planetary carrier 41 is a radial bearing 5. Specifically, the upper end of the planetary gear 22 is provided with a stepped shaft section that mates with the radial bearing 5 and the upper planetary carrier 41. Optionally, the inner sun gear 23, the outer sun gear 21, and the planetary gear 22 are all spur gears.

[0034] This embodiment relies on its own motion laws to achieve the cross-track cutting of the central drill bit 31 and the planetary drill bit 32. During downhole drilling, geological conditions have little impact, thus the movement of the central drill bit 31 and the planetary drill bit 32 and the cross-track cutting method are stable and reliable. The cutting section 3 in this embodiment includes both the cutting teeth on the planetary drill bit 32, which is fixedly connected to the planetary gear 22, and the cutting teeth on the central drill bit 31. Both are on the same cutting profile, which increases the cutting area during operation, thereby improving drilling rock-breaking efficiency. In this embodiment, the central drill bit 31 and the planetary drill bit 32 rotate in opposite directions. A reasonable arrangement of the cutting section 3 can achieve torque balance, thereby reducing the torque input to the drill string and significantly improving rock-breaking efficiency. During operation, the central drill bit 31 and the planetary drill bit 32 move non-eccentrically, and the cutting teeth have good symmetry in contact with the rock, resulting in relatively small lateral unbalanced forces. This is beneficial for the stable operation of the central drill bit 31 and the planetary drill bit 32, extending the service life of the drill bit and the overall mechanism.

[0035] The motion cutting trajectories of the center drill bit 31 and the planetary drill bit 32 satisfy the following equation:

[0036] In the equation: x - x-coordinate of the planetary drill bit; y - y-coordinate of the planetary drill bit; X - x-coordinate of the center drill bit; Y - y-coordinate of the center drill bit; r - positioning radius of the cutting teeth of the planetary drill bit; R - positioning radius of the planetary drill bit; R r - Center drill bit cutting tooth positioning radius; θ - Rotation angle; i - Planetary gear transmission ratio.

[0037] In this technical solution, the motion cutting trajectory must satisfy the above equation. By changing the control parameters, different cutting trajectories can be obtained, thus obtaining the optimal structural parameters for the operation of this device and achieving the best rock-breaking effect.

[0038] Example 2

[0039] This embodiment is basically the same as Embodiment 1, except that different cutting trajectories are obtained by changing the positioning radius of the planetary drill bit's cutting teeth. For example... Figure 9 and 10 As shown, in this embodiment, when the positioning radius of the planetary drill bit's cutting teeth decreases, the helixity of the spiral formed by its cutting trajectory decreases. Figure 9 The positioning radius of the corresponding planetary drill bit cutting teeth is greater than Figure 10 The positioning radius of the corresponding planetary drill bit cutting teeth.

[0040] Example 3

[0041] This embodiment is basically the same as Embodiment 1, except that different cutting trajectories are obtained by changing the positioning radius of the central drill bit cutting teeth. For example... Figure 11 and 12 As shown, in this embodiment, when the positioning radius of the central drill bit cutting tooth decreases, the radius of the circle formed by its cutting trajectory decreases; Figure 11 The positioning radius of the corresponding center drill bit cutting teeth is greater than Figure 12 The positioning radius of the corresponding center drill bit cutting teeth.

[0042] Example 4

[0043] This embodiment is basically the same as Embodiment 1, except that different cutting trajectories are obtained by changing the planetary gear train transmission ratio. For example... Figure 13 and 14 As shown, in this embodiment, when the transmission ratio decreases, the number of spirals formed by the planetary drill bit's cutting trajectory decreases; Figure 13 The corresponding planetary gear train transmission ratio is greater than Figure 14 The corresponding planetary gear train ratio.

[0044] Example 5

[0045] like Figure 15 and 16 As shown, this embodiment is basically the same as embodiment 1, except that: the transmission part 2 includes an outer sun gear 21, an inner sun gear 23 and four planetary gears 22, and the four planetary drill bits 32 are respectively fixedly connected to the four planetary gears 22, and are driven by the planetary gears 22 to rotate and break rocks; the central drill bit 31 has the same structure as embodiment 1, that is, cutting teeth are arranged on the lower end face and side wall of the central drill bit 31, but only the outer teeth 31b and the diameter-maintaining teeth 31c are included, and no core teeth are provided. The nozzle 8 is provided at the center of the lower end face of the central drill bit 31.

[0046] In this embodiment, four planetary gears 22 and four planetary drill bits 32 moving synchronously with them are arranged. The four planetary drill bits 32 and the central drill bit 31 together form the cutting section 3. The alternating cutting trajectory has a higher degree of alternation, which makes the rock form more "raised" parts in the cutting direction, allowing the cutting teeth to more naturally engulf the rock and improve the rock breaking efficiency. At the same time, the rotation direction of the four planetary drill bits 32 is opposite to that of the central drill bit 31, which makes the torque balance effect more obvious and reduces the torque transmitted to the drill string.

[0047] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A differential drilling rock-breaking tool, characterized in that, include: Power Department; The transmission unit includes an outer sun gear, an inner sun gear, and a plurality of planet gears constituting a planetary gear train structure. The outer sun gear is fixedly connected to the housing of the power unit, and the inner sun gear is connected to the power unit. The cutting part includes a central drill bit and planetary drill bits that correspond one-to-one with the planetary gears. The central drill bit is located at the lower end of the inner sun gear and moves synchronously with the inner sun gear. The planetary drill bits are located at the lower end of the planetary gears and move synchronously with the corresponding planetary gears. The central drill bit and the planetary drill bits are respectively provided with cutting teeth. The cutting teeth of the central drill bit include external teeth and gauge-keeping teeth. Multiple sets of external teeth are radially disposed on the lower end face of the central drill bit, and the gauge-keeping teeth are disposed on the side wall of the central drill bit along the extension path of the external teeth. The cutting teeth of the central drill bit also include core teeth, which are located in the middle of the lower end face of the central drill bit; The upper end of the planetary gear is provided with an upper planetary carrier, the upper end of the planetary gear is connected to the upper planetary carrier through a bearing, and the lower end of the planetary gear is connected to the central drill bit through a bearing. The central drill bit is provided with multiple through holes for mounting the planetary drill bit. The upper end of the planetary drill bit extends into the through hole and is threadedly connected to the lower end of the planetary gear. A bearing is provided inside the through hole. The transmission unit is assembled into the housing of the motor assembly, and the outer sun gear is splined to the inner wall of the housing.

2. The differential drilling rock-breaking tool according to claim 1, characterized in that, The central drill bit is also provided with a nozzle, which is located near the center of the central drill bit and avoids the planetary drill bit.

3. The differential drilling rock-breaking tool according to claim 1, characterized in that, The planetary drill bit is a blade-type PDC drill bit, and the cutting teeth of the center drill bit are arranged in the opposite direction to the cutting teeth of the planetary drill bit.

4. The differential drilling rock-breaking tool according to claim 1, characterized in that, The bearing between the upper end of the planetary gear and the upper planet carrier is a radial bearing.

5. The differential drilling rock-breaking tool according to claim 1, characterized in that, The power unit includes a universal joint assembly and a motor assembly. The upper end of the inner sun gear is threadedly connected to the lower connector of the universal joint assembly, and the lower end of the inner sun gear is threadedly connected to the upper end of the center drill bit.

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