A reamer and a structure of its cone bit

Abstract

This invention provides a reamer and a roller cone drill bit structure, relating to the field of trenchless reaming tools. The reamer includes a toothed shaft and a roller cone rotatably connected to the toothed shaft. The toothed shaft has a first water jet and a second water jet, located on the front and rear sides of the roller cone, respectively. The first water jet is inclined and its opening direction faces the roller cone; the second water jet is also inclined and its opening direction faces the tangential direction of the outer edge of the roller cone, so that the fluid ejected from the second water jet can be sprayed onto the surface of the roller cone and carried to the outer wall of the toothed shaft as the roller cone rotates. This invention, by adding a second water jet and cleverly utilizing the rotation of the roller cone itself, carries water to the outer wall of the toothed shaft, effectively solving the problem of cleaning and lubrication of the outer wall of the toothed shaft, reducing metal dry friction and wear, and protecting the sealing structure.

Description

Technical Field

[0001] This invention relates to the field of hole reaming machinery, and in particular, to a hole reamer and its roller cone drill bit structure. Background Technology

[0002] Currently, Chinese patent CN222686607U discloses a non-excavation reaming drill bit, including a mounting shaft, a first truncated cone on the mounting shaft, multiple toothed teeth on the first truncated cone, each toothed tooth having a toothed wheel, multiple movable grooves on the first truncated cone, each movable groove having a fixed shaft, the middle parts of the multiple toothed teeth being hinged to multiple fixed shafts, and the mounting shaft also having multiple sets of control components for controlling the rotation of the multiple toothed teeth respectively.

[0003] Currently, in the conventional application of the aforementioned reaming drill bits, in order to promptly remove debris, the drill bit is usually equipped with only a unidirectional inclined water nozzle, and the opening direction of the water nozzle is mainly towards the front side of the drill cone, in order to clean the drill cone. This single nozzle arrangement results in a scouring blind zone, where high-pressure mud cannot cover and scour the side of the drill bit facing the wellhead inner wall, i.e., the outer wall of the drill bit.

[0004] Due to the lack of effective cleaning and lubrication from water flow, the outer wall of the drill bit experiences continuous and intense friction against the inner wall of the wellhead in the complex bottom hole environment. This direct dry friction causes severe wear on the metal of the outer wall of the drill bit, and once this wear spreads to the sealing area at the bottom of the drill bit, it directly compromises the seal between the drill bit and the cone. Seal failure allows mud and cuttings to enter the cone's internal bearings, ultimately leading to stuck drill bit or premature drill bit failure. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a hole reamer and its roller cone drill bit structure, which solves the problem that existing hole reamers have blind spots on the outer wall of the tooth due to the single arrangement of water nozzles, which leads to dry friction, wear of the sealing structure and premature scrapping of the drill bit.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a hole expander, including a toothed plate and a toothed wheel, wherein the toothed wheel is rotatably connected to the toothed plate, and the toothed plate is provided with a first water spray nozzle and a second water spray nozzle, the first water spray nozzle and the second water spray nozzle are respectively located on the front and rear sides of the toothed wheel, the first water spray nozzle is inclined and the opening direction of the first water spray nozzle faces the toothed wheel, and the second water spray nozzle is inclined and the opening direction of the second water spray nozzle faces the tangential direction of the outer edge of the toothed wheel, so that the fluid sprayed from the second water spray nozzle can be sprayed onto the surface of the toothed wheel and carried to the outer wall of the toothed plate as the toothed wheel rotates.

[0007] To achieve the above technical solution, a first and second water jet are installed on the borehole shaft. During the reaming process, the fluid ejected from the first jet directly flushes the front side of the borehole cone; the fluid ejected from the second jet is sprayed tangentially along the outer edge of the borehole cone onto its surface. The rotational motion of the borehole cone at the bottom of the hole continuously carries the fluid to the outer wall of the borehole shaft. This effectively improves the problem of insufficient fluid cleaning and lubrication on the outer wall of the borehole shaft, reduces dry friction between the outer wall of the borehole shaft and the inner wall of the wellhead, slows the spread of metal wear to the sealing area at the bottom of the borehole shaft, thereby protecting the sealing structure and reducing the risk of early stuck pipe caused by mud intrusion.

[0008] As a preferred embodiment of the present invention, the opening of the second water nozzle is inclined toward the outer wall of the palm, and the inclination angle of the second water nozzle toward the outer wall of the palm is greater than the inclination angle of the first water nozzle.

[0009] To achieve the above technical solution, the opening of the second water nozzle is tilted towards the outer wall of the tooth, and its tilt angle is greater than that of the first water nozzle. During the fluid injection process, this tilting design allows the fluid to be more accurately guided to the narrow gap between the outer wall of the tooth and the inner wall of the wellhead. This improves the transmission efficiency and coverage of the fluid carried by the roller to the outer wall of the tooth, and further enhances the flushing, cooling and lubrication effect on the outer wall of the tooth.

[0010] In a preferred embodiment of the present invention, the roller is rotatably connected to the toothed plate via a bearing, the bearing including a support shaft and a ball, the support shaft being connected to the toothed plate, the support shaft having a first annular groove, the inner wall of the roller having a second annular groove, a channel for the ball to roll being formed between the first annular groove and the second annular groove, the toothed plate having a ball-loading hole, the ball-loading hole passing through the support shaft and communicating with the first annular groove, and a sealing structure being provided between the roller and the support shaft.

[0011] To achieve the above technical solution, the roller is rotatably connected to the toothed shaft via a bearing. When the roller rotates, the balls roll in the channel formed by the first and second annular grooves, ensuring the smooth rotation of the roller and bearing the radial and axial loads during operation. At the same time, the design of the ball loading hole passing through the support shaft facilitates the assembly of the balls. Combined with the sealing structure, it effectively prevents external rock chips from entering the channel through which the balls roll, thus extending the service life.

[0012] In a preferred embodiment of the present invention, the sealing structure includes a first sealing ring, a first protrusion, and a second protrusion. A first protective ring groove is provided on the side of the toothed wheel near the tooth, and a first receiving ring groove is provided on the toothed wheel. A second protrusion is provided between the first protective ring groove and the first receiving ring groove. A first protrusion for being located in the first protective ring groove is connected to one end of the support shaft near the tooth. A second protective ring groove for accommodating the second protrusion is provided on the outer wall of the support shaft. The first sealing ring is embedded in the first receiving ring groove, and the inner wall of the first sealing ring abuts against the outer wall of the support shaft.

[0013] To achieve the above technical solution, during the rotation of the roller around the support shaft, a water-blocking structure is formed between the first convex part, the second convex part, the first protective ring groove, and the second protective ring groove, which increases the flow path length and resistance of external mud and rock debris entering the bearing; combined with the tightness between the inner wall of the first sealing ring and the outer wall of the support shaft, the probability of fluid infiltration is further reduced, and the reliability of the sealing structure is improved.

[0014] As a preferred embodiment of the present invention, the sealing structure further includes a second sealing ring. The inner wall of the toothed wheel is provided with a second receiving ring groove that communicates with the first receiving ring groove. The second receiving ring groove is located on the side of the first receiving ring groove away from the tooth. The second sealing ring is embedded in the second receiving ring groove and the inner wall of the second sealing ring abuts against the outer wall of the support shaft.

[0015] By implementing the above technical solution, the second sealing ring and the first sealing ring form a double sealing barrier in complex drilling conditions. When dealing with fluctuations in the mud pressure at the bottom of the hole, the second sealing ring can provide secondary protection, which greatly reduces the probability of mud intruding into the ball bearings.

[0016] As a preferred embodiment of the present invention, the sealing structure further includes a third protrusion connected to the inner wall of the roller, the third protrusion being located between the first receiving ring groove and the second receiving ring groove.

[0017] To achieve the above technical solution, a third protrusion is provided on the inner wall of the roller cone between the first receiving ring groove and the second receiving ring groove. Under the conditions of roller cone rotation and vibration, the third protrusion plays a role in physical positioning and support, restricting the axial movement of the first sealing ring and the second sealing ring, and ensuring the stability of the first sealing ring and the second sealing ring.

[0018] In a preferred embodiment of the present invention, the cross-sectional area of ​​the second sealing ring is larger than that of the first sealing ring.

[0019] To achieve the above technical solution, by setting the cross-sectional area of ​​the second sealing ring to be larger than that of the first sealing ring, the second sealing ring located on the inner side has a stronger deformation recovery capability and compressive strength. When facing possible internal pressure fluctuations, the large-section second sealing ring can provide a more durable and tighter fit.

[0020] In a preferred embodiment of the present invention, the two end faces of the second sealing ring are contact planes, and the inner wall of the second sealing ring is a contact arc surface that abuts against the outer wall of the support shaft.

[0021] To achieve the above technical solution, the two end faces of the second sealing ring are contact planes, which restricts the rolling of the second sealing ring in the second receiving ring groove; the inner wall of the second sealing ring is a contact arc surface, which abuts against the outer wall of the support shaft to form a dynamic sealing structure with line-surface combination, which reduces the frictional loss between the sealing ring and the support shaft while ensuring the sealing pressure.

[0022] The present invention also provides a roller cone drill bit structure, including a support base and a plurality of reamers, wherein the drill bits are connected to the support base, and the support base has mounting holes for connecting water pipes, and the plurality of drill bits are evenly distributed along the axis of the mounting holes.

[0023] To achieve the above technical solution, multiple reamers are evenly distributed along the axis of the mounting hole on the support base. When the drilling fluid is pumped, the high-pressure fluid is evenly distributed to the first and second water jets of each tooth through the mounting hole, realizing the synchronous flushing and lubrication of multiple sets of tooth cones, and improving the rock breaking efficiency and operational stability of the overall drill bit structure in complex formations. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Example 1; Figure 2 To illustrate the structure of the palm; Figure 3 To illustrate the structure of the second water jet; Figure 4 To illustrate the structure of the first water jet; Figure 5 This is a cross-sectional view of Example 1; Figure 6 for Figure 5 Enlarged view of point A; Figure 7 This is a structural diagram of Example 2.

[0025] Reference numerals: 1. Expander; 2. Tooth; 3. Toothed wheel; 4. Carbide tooth; 5. First nozzle; 6. Second nozzle; 7. Bearing; 8. Support shaft; 9. Ball bearing; 10. First annular groove; 11. Second annular groove; 12. Ball loading hole; 13. Sealing structure; 14. First sealing ring; 15. Second sealing ring; 16. First protrusion; 17. Second protrusion; 18. Third protrusion; 19. First protective ring groove; 20. First receiving ring groove; 21. Second protective ring groove; 22. Second receiving ring groove; 23. Contact plane; 24. Support seat; 25. Mounting hole. Detailed Implementation

[0026] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so that the technical solution of the present invention can be more easily understood and mastered.

[0027] Example 1: A hole expander includes a toothed prong 2 and a toothed wheel 3. The toothed prong 2 is forged from high-strength alloy steel; the outer surface of the toothed wheel 3 is inlaid with hard alloy teeth 4 for contacting and breaking rocks.

[0028] A first water jet 5 and a second water jet 6 are provided on the toothed wheel 2. The first water jet 5 and the second water jet 6 are located on the front and rear sides of the toothed wheel 3, respectively. The toothed wheel 2 rotates in the forward direction. The first water jet 5 is inclined and its opening direction faces the toothed wheel 3, and is used to directly wash away rock debris attached to the front side of the toothed wheel 3. The second water jet 6 is inclined and its opening direction faces the tangential direction of the outer edge of the toothed wheel 3.

[0029] The opening of the second water nozzle 6 is inclined toward the outer wall of the palm 2, and the inclination angle of the second water nozzle 6 toward the outer wall of the palm 2 is greater than the inclination angle of the first water nozzle 5.

[0030] The bearing 7 includes a support shaft 8 and balls 9. The support shaft 8 is fixedly connected to the gear 2. A first annular groove 10 is formed on the support shaft 8, and a second annular groove 11 is formed on the inner wall of the gear 3. When the gear 3 is fitted onto the support shaft 8, the first annular groove 10 and the second annular groove 11 are aligned with each other, forming a channel for the balls 9 to roll. To facilitate assembly, a ball-filling hole 12 is formed on the gear 2. The ball-filling hole 12 passes through the support shaft 8 and communicates directly with the first annular groove 10. During assembly, the balls 9 are filled into the channel one by one through the ball-filling hole 12, and the ball-filling hole 12 is closed after filling.

[0031] A sealing structure 13 is provided between the roller 3 and the support shaft 8. The sealing structure 13 includes a first sealing ring 14, a second sealing ring 15, a first protrusion 16, a second protrusion 17, and a third protrusion 18. The first sealing ring 14 and the second sealing ring 15 are made of wear-resistant and high-temperature resistant hydrogenated nitrile rubber.

[0032] A first protective ring groove 19 is formed on the side of the gear 3 near the toothed end 2, and a first receiving ring groove 20 is formed on the gear 3. A second protrusion 17 is integrally formed between the first protective ring groove 19 and the first receiving ring groove 20. A first protrusion 16 for being located in the first protective ring groove 19 is connected to one end of the support shaft 8 near the toothed end 2, and a second protective ring groove 21 for accommodating the second protrusion 17 is formed on the outer wall of the support shaft 8.

[0033] The first sealing ring 14 is embedded in the first receiving ring groove 20, and the inner wall of the first sealing ring 14 is tightly pressed against the outer wall of the support shaft 8, forming the first dynamic sealing defense line.

[0034] The inner wall of the roller cone 3 is provided with a second receiving ring groove 22 that communicates with the first receiving ring groove 20. The second receiving ring groove 22 is located on the side of the first receiving ring groove 20 away from the tooth palm 2. The sealing structure 13 also includes a third protrusion 18 connected to the inner wall of the roller cone 3. The third protrusion 18 is located between the first receiving ring groove 20 and the second receiving ring groove 22.

[0035] The second sealing ring 15 is embedded in the middle of the second receiving ring groove 22, and the inner wall of the second sealing ring 15 abuts against the outer wall of the support shaft 8, thereby forming a second dynamic sealing defense line.

[0036] The cross-sectional area of ​​the second sealing ring 15 is larger than that of the first sealing ring 14. The two end faces of the second sealing ring 15 are contact planes 23, which abut against the inner wall of the second receiving ring groove 22. The inner wall of the second sealing ring 15 is a contact arc surface, which abuts against the outer wall of the support shaft 8.

[0037] Example 2: A roller cone drill bit structure includes a support base 24 and a reamer 1 as described in Example 1. The teeth 2 of the reamer 1 are fixedly connected to the support base 24. The support base 24 has a mounting hole 25 for connecting a water pipe at its center, and multiple teeth 2 are evenly distributed around the periphery of the support base 24 along the axis of the mounting hole 25.

[0038] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A hole expander, comprising a toothed plate (2) and a toothed wheel (3), wherein the toothed wheel (3) is rotatably connected to the toothed plate (2), characterized in that: The toothed palm (2) is provided with a first water spray nozzle (5) and a second water spray nozzle (6). The first water spray nozzle (5) and the second water spray nozzle (6) are located on the front and rear sides of the toothed wheel (3), respectively. The first water spray nozzle (5) is inclined and the opening direction of the first water spray nozzle (5) is facing the toothed wheel (3). The second water spray nozzle (6) is inclined and the opening direction of the second water spray nozzle (6) is facing the tangential direction of the outer edge of the toothed wheel (3), so that the fluid sprayed from the second water spray nozzle (6) can be sprayed onto the surface of the toothed wheel (3) and carried to the outer wall of the toothed palm (2) as the toothed wheel (3) rotates.

2. The hole expander according to claim 1, characterized in that: The opening of the second water nozzle (6) is inclined toward the outer wall of the palm (2), and the tilt angle of the second water nozzle (6) toward the outer wall of the palm (2) is greater than the tilt angle of the first water nozzle (5).

3. The hole expander according to claim 1, characterized in that: The toothed wheel (3) is rotatably connected to the toothed palm (2) via a bearing (7). The bearing (7) includes a support shaft (8) and a ball (9). The support shaft (8) is connected to the toothed palm (2). A first annular groove (10) is provided on the support shaft (8). A second annular groove (11) is provided on the inner wall of the toothed wheel (3). A channel for the ball (9) to roll is formed between the first annular groove (10) and the second annular groove (11). A ball-loading hole (12) is provided on the toothed palm (2). The ball-loading hole (12) passes through the support shaft (8) and communicates with the first annular groove (10). A sealing structure (13) is provided between the toothed wheel (3) and the support shaft (8).

4. A hole expander according to claim 3, characterized in that: The sealing structure (13) includes a first sealing ring (14), a first protrusion (16), and a second protrusion (17). The toothed wheel (3) has a first protective ring groove (19) on the side near the toothed edge (2). The toothed wheel (3) has a first receiving ring groove (20). The second protrusion (17) is provided between the first protective ring groove (19) and the first receiving ring groove (20). The support shaft (8) has a first protrusion (16) located in the first protective ring groove (19) at one end near the toothed edge (2). The outer wall of the support shaft (8) has a second protective ring groove (21) for accommodating the second protrusion (17). The first sealing ring (14) is embedded in the first receiving ring groove (20), and the inner wall of the first sealing ring (14) abuts against the outer wall of the support shaft (8).

5. A hole expander according to claim 4, characterized in that: The sealing structure (13) further includes a second sealing ring (15). The inner wall of the toothed wheel (3) is provided with a second receiving ring groove (22) that communicates with the first receiving ring groove (20). The second receiving ring groove (22) is located on the side of the first receiving ring groove (20) away from the toothed wheel (2). The second sealing ring (15) is embedded in the second receiving ring groove (22) and the inner wall of the second sealing ring (15) abuts against the outer wall of the support shaft (8).

6. A hole expander according to claim 5, characterized in that: The sealing structure (13) also includes a third protrusion (18) connected to the inner wall of the toothed wheel (3), the third protrusion (18) being located between the first receiving ring groove (20) and the second receiving ring groove (22).

7. A hole expander according to claim 5, characterized in that: The cross-sectional area of ​​the second sealing ring (15) is greater than that of the first sealing ring (14).

8. A hole expander according to claim 7, characterized in that: The two ends of the second sealing ring (15) are contact planes (23), and the inner wall of the second sealing ring (15) is a contact arc surface and abuts against the outer wall of the support shaft (8).

9. A roller cone drill bit structure, comprising a support base (24), characterized in that: It also includes a plurality of hole expanders (1) as described in any one of claims 1-8, wherein the toothed pads (2) are connected to a support base (24), and the support base (24) has mounting holes (25) for connecting water pipes, and the plurality of toothed pads (2) are evenly distributed along the axis of the mounting holes (25).

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