Flat sealing device for roller bit

Abstract

The invention relates to a flat sealing device for a roller bit, which belongs to the technical field of petroleum and geological drilling and comprises a bit leg connected with a bit leg journal. The cone is provided with a bearing hole, and the bearing hole is arranged on the cone palm shaft neck in a sleeving manner, so that a cone bit bearing is formed; a sealing groove is formed in the outer end of the bearing hole, the sealing ring is arranged in the sealing groove, a plurality of annular grooves are formed in the side face of the sealing ring, and a protrusion is formed in the connecting position of every two adjacent annular grooves; protrusions are formed at the connecting positions of the adjacent ring grooves, the protrusions are tightly attached to the inner walls of the sealing grooves, a supporting structure is constructed, the sealing ring obtains excellent distortion resistance while keeping the characteristic of easy deformation, and the contact pressure of the sealing ring is small due to the characteristic of easy deformation.

Description

Technical Field

[0001] This application relates to the field of oil and geological drilling technology, and in particular to a flat sealing device for roller cone drill bits. Background Technology

[0002] As a critical tool in oil and gas drilling operations, the reliability of the bearing sealing system of roller cone bits directly determines the service life and drilling efficiency of the bit. During drilling, the bearing system of roller cone bits needs to operate stably for extended periods under harsh conditions such as high temperature, high pressure, strong vibration, and mud erosion. The bearing sealing structure is a crucial barrier to prevent external mud from entering the bearing and internal grease from leaking.

[0003] Currently, existing metal-sealed drill bits are suitable for high-speed drilling. However, because metal seals are end-face seals, they are prone to failure after bearing wear under drilling conditions with large deflections, resulting in low reliability. While O-ring rubber seals are radial seals and can adapt to drilling conditions with large deflections, their high friction and heat generation make them unsuitable for high-speed operation, leading to premature seal failure. Finally, among rubber seals, flat sealing rings with high longitudinal and transverse characteristics occupy less axial space and have a higher compression ratio than O-rings for the same inner diameter, effectively compensating for wear in the sealing contact. However, after bearing wear, the sealing ring undergoes eccentric compression. Due to varying compression amounts at different locations, the flat sealing ring deforms differently under the pressure difference, posing a risk of twisting and affecting its lifespan. Summary of the Invention

[0004] This application provides a flat sealing device for roller cone drill bits to solve the problem in related technologies where uneven compression of the sealing ring due to eccentric compression after bearing wear, and easy twisting under the action of internal and external pressure difference, thus affecting the sealing life.

[0005] A flat sealing device for a roller cone drill bit is provided, comprising: a toothed shaft with a toothed shaft journal connected thereto; a roller cone with a bearing hole, the bearing hole being fitted onto the toothed shaft journal to form a roller cone drill bit bearing; and a sealing ring with a sealing groove at the outer end of the bearing hole, the sealing ring being disposed within the sealing groove, and the side of the sealing ring having multiple annular grooves, with a protrusion forming at the connection between two adjacent annular grooves.

[0006] By adopting the above technical solution, when the roller and the journal of the roller rotate relative to each other, the protrusion can work together to form a dynamic adaptive contact on the sealing strip. Even when the axial swing angle of the roller is large, the protrusion can automatically adjust the contact pressure distribution according to the actual displacement, thus avoiding the instantaneous failure problem caused by the complete detachment of a single contact surface under flexion in traditional metal end face seals.

[0007] In some embodiments, the rotating section of the sealing ring is rectangular, and an outer sealing portion is provided on the outer ring of the sealing ring. The outer sealing portion is an arc shape that protrudes radially outward with reference to the central axis of the sealing ring. An inner sealing portion is provided on the inner ring of the sealing ring. The inner sealing portion is an arc shape that protrudes radially inward with reference to the central axis of the sealing ring.

[0008] By adopting the above technical solution: the arc-shaped outer sealing part and the sealing groove form an optimized contact interface. When the toothed wheel swings eccentrically, the arc-shaped outer sealing part can automatically adjust the contact position and form a dynamic balance of contact pressure on the entire circumference, which significantly improves the barrier against external mud intrusion. The inner sealing part and the toothed shaft journal form a second sealing barrier and work together with the outer sealing part to significantly reduce the grease leakage rate. The outer side of the sealing ring bears the external high-pressure mud, and the inner side of the sealing ring bears the internal grease pressure. The two are connected by a rigid rectangular cross section to form a pressure balance system.

[0009] In some embodiments, the protrusion is arc-shaped and flush with the outer sealing portion and the inner sealing portion.

[0010] By adopting the above technical solution, the design of setting the protrusion as arc-shaped and flush with the outer and inner sealing parts works synergistically to transform the originally discrete support structure into a seamless sealing strip, avoiding stress concentration when it is matched with the sealing groove; the flush design ensures that the protrusion, outer sealing part and inner sealing part can work together to maintain a stable sealing interface during the process of eccentric angle change.

[0011] In some embodiments, the protrusion is arc-shaped, and the contour of the protrusion is lower than the contours of the outer seal and the inner seal.

[0012] By adopting the above technical solution, the protrusion profile is lower than the outer sealing part and the inner sealing part to construct a sealing structure for use under low pressure difference conditions. The supporting effect of the protrusion is appropriately weakened, and the sealing structure is easy to deform under low pressure difference conditions, which reduces the sealing contact pressure and reduces sealing heat generation, thus helping to improve the sealing life under low pressure difference conditions.

[0013] In some embodiments, the protrusion is cone-shaped and flush with the outer sealing portion and the inner sealing portion.

[0014] By adopting the above technical solution, the conical protrusion forms a line contact, and the stress is evenly distributed along the conical line, providing higher compressive stiffness and more stable contact characteristics, which is particularly suitable for high pressure differential working conditions.

[0015] In some embodiments, the protrusion is cone-shaped, and the profile of the protrusion is lower than the profiles of the outer seal and the inner seal.

[0016] By adopting the above technical solution: under initial working conditions, the outer sealing part and the inner sealing part, as the main sealing surfaces, make initial contact first, forming a small initial contact area; when the roller bearing becomes eccentric due to wear or the drilling deflection increases, the conical protrusion gradually participates in the contact. Its conical structure makes the contact stress evenly distributed along the conical line, avoiding the central stress concentration that may be generated by the arc-shaped protrusion. The structure of the protrusion profile being lower than that of the sealing part provides wear compensation space, significantly extending the effective working time of the sealing system.

[0017] In some embodiments, the annular groove is configured as a V-shape, and the distance between the protrusion formed between adjacent annular grooves and the line connecting the inner and outer contours of the sealing ring is 0~1mm.

[0018] By adopting the above technical solution, through precise geometric design, an approximately continuous sealing contact zone is formed, which achieves uniform pressure distribution and effective stress dispersion, thereby reducing the maximum contact stress.

[0019] In some embodiments, the sealing ring has at least two annular grooves on each side.

[0020] By adopting the above technical solution: at least two annular grooves are provided on each side, corresponding to at least one protrusion. The protrusion support can more effectively disperse the pressure and prevent the sealing ring from twisting and deforming due to excessive local stress, so that the sealing ring can maintain a stable structural shape under harsh working conditions.

[0021] In some embodiments, the sealing ring has two annular grooves on one side and three annular grooves on the other side.

[0022] By adopting the above technical solution: the sealing ring has one annular groove on one side and one annular groove on the other side, and one protrusion on one side and two protrusions on the other side. The different number of annular grooves will cause differences in the deformation and contact pressure distribution on both sides of the sealing ring. During the operation, this difference can make the contact between the sealing ring and the inner wall of the sealing groove more compact and uniform.

[0023] In some embodiments, the sealing ring is made of a polymer material.

[0024] By adopting the above technical solutions, polymer materials provide high reliability, long life and wide adaptability for complex drilling environments.

[0025] The beneficial effects of the technical solution provided in this application include: This application provides a flat sealing device for roller cone drill bits. By setting multiple annular grooves on the side of the sealing ring, a protrusion is formed at the connection of adjacent annular grooves. The protrusion fits tightly with the inner wall of the sealing groove, constructing a support structure. This allows the sealing ring to maintain its deformable characteristics while obtaining excellent anti-torsion ability. The deformable characteristics result in lower contact pressure on the sealing ring, significantly reducing frictional heat and wear at the sealing interface. The protrusion, which plays a supporting role, is squeezed and fits tightly with the sealing groove, ensuring that the sealing ring can still maintain structural stability under harsh working conditions such as bearing eccentricity and uneven compression, avoiding overall distortion caused by local excessive compression. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0027] Figure 1 This is a schematic diagram of the overall structure provided in Embodiment 1 of this application;

[0028] Figure 2 This is a partial schematic diagram of the sealing portion of a roller cone drill bit bearing, provided in Embodiment 1 of this application. Figure 3 This is a schematic diagram illustrating the annular groove provided in Embodiment 1 of this application; Figure 4 This is a schematic diagram illustrating the protrusion provided in Embodiment 1 of this application; Figure 5 This is a schematic diagram illustrating the protrusion provided in Embodiment 2 of this application; Figure 6 This is a schematic diagram illustrating the protrusion provided in Embodiment 3 of this application; Figure 7 This is a schematic diagram illustrating the protrusion provided in Embodiment 4 of this application.

[0029] In the diagram: 1. Toothed palm; 10. Toothed palm journal; 2. Toothed wheel; 20. Bearing hole; 3. Sealing groove; 30. Sealing ring; 31. Annular groove; 32. Protrusion; 4. Outer sealing part; 5. Inner sealing part; 6. Steel ball; 7. Grease hole; 8. Plug pin; 80. Plug pin hole. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] This application provides a flat sealing device for roller cone drill bits, which can solve the problem in related technologies that uneven compression of the sealing ring due to eccentric compression after bearing wear, and easy twisting under the action of internal and external pressure difference, thus affecting the sealing life.

[0032] Example 1 Reference Figure 1-4 A flat sealing device for a roller cone drill bit includes a toothed shaft 1, a roller cone 2, and a seal. A toothed shaft journal 10 is connected to the toothed shaft 1; the roller cone 2 has a bearing hole 20, which is fitted onto the toothed shaft journal 10 to form a roller cone drill bit bearing; a sealing groove 3 is provided at the outer end of the bearing hole 20, and a sealing ring 30 is disposed within the sealing groove 3. Multiple annular grooves 31 are provided on the side of the sealing ring 30, and a protrusion 32 is formed at the connection point of two adjacent annular grooves 31. In this embodiment, a plug pin hole 80 is also provided on the toothed shaft journal 10. A steel ball 6 is inserted into the bearing through the plug pin hole 80, and then the plug pin 8 is welded and fixed. The roller cone 2 is axially held on the toothed shaft journal 10 by the steel ball 6, and a grease hole 7 provides grease to the drill bit bearing.

[0033] This application employs a method that carefully incorporates multiple annular grooves 31 on the side of the sealing ring 30, with protrusions 32 naturally forming at the junctions of adjacent grooves 31. These protrusions 32 fit snugly against the inner wall of the sealing groove 3, creating a support structure. This results in lower contact pressure when the sealing ring 30 contacts the sealing surface. During the high-speed rotation of the drill bit, this lower contact pressure significantly reduces frictional heat at the sealing interface. This reduction in frictional heat not only prevents degradation of the sealing material's performance due to localized overheating but also significantly reduces wear between the sealing ring 30 and adjacent components. Reduced wear effectively extends the service life of the sealing device, improving the continuity and efficiency of drilling operations.

[0034] On the other hand, the protrusion 32, which provides support, fits tightly against the sealing groove 3 when compressed. Drilling operations often encounter harsh conditions such as bearing eccentricity and uneven compression. In these complex situations, the support structure plays a crucial role. The protrusion 32 evenly distributes pressure, ensuring that the sealing ring 30 is subjected to balanced force in all parts, thereby maintaining structural stability. This avoids overall distortion caused by excessive local compression, ensuring that the sealing ring 30 always fits tightly against the sealing surface, effectively preventing leakage of drilling fluid and other media.

[0035] In this embodiment, the sealing ring 30 is made of a polymer material. The polymer material includes, but is not limited to, nitrile rubber, hydrogenated nitrile rubber, fluororubber, polytetrafluoroethylene (PTFE), or aramid fiber. The sealing ring 30 is made of at least one of these materials or a composite of multiple of them. Hydrogenated nitrile rubber has excellent temperature resistance and elasticity, which can improve the problem of high heat generation during high-speed operation of the sealing ring 30, reducing frictional heat. Fluororubber is adaptable to extreme temperature environments and can effectively cope with the high-temperature challenges in deep well drilling. PTFE composite significantly reduces the coefficient of friction, lowering the interface temperature during high-speed rotation and preventing thermal degradation of the sealing material. Aramid fiber reinforcement improves tensile strength and wear resistance, fundamentally improving the problem of easy twisting of the flat sealing ring 30 under eccentric compression. When a multi-material composite structure is adopted, a functionally optimized sealing system is formed, providing an innovative sealing solution with high reliability, long life, and wide adaptability for complex drilling environments.

[0036] In this application, the sealing ring 30 has at least two annular grooves 31 on each side, and at least one protrusion 32 on each side forms a support structure. When facing complex operating conditions such as bearing eccentricity and uneven compression, the protrusions 32 can support and constrain the sealing ring 30. This allows the sealing ring 30 to maintain its deformability while achieving excellent torsional resistance. The deformability results in lower contact pressure on the sealing ring 30, significantly reducing frictional heat and wear at the sealing interface. Furthermore, the protrusions 32, which provide support, are compressed and fit against the sealing grooves 3, ensuring that the sealing ring 30 maintains structural stability even under harsh conditions of bearing eccentricity and uneven compression, avoiding overall torsion caused by excessive local compression.

[0037] Reference Figure 3 In some optional embodiments, when the sealing ring 30 has two or more annular grooves 31 on each side, there are at least two protrusions 32 on each side. Compared with a single or fewer protrusions 32, multi-point support can more effectively distribute pressure, preventing the sealing ring 30 from twisting and deforming due to excessive local stress, and ensuring that the sealing ring 30 maintains a stable structural shape under harsh working conditions. Furthermore, the multiple protrusions 32 cooperate with each other to tightly connect the sealing ring 30 to the sealing groove 3, enhancing the overall integrity of the sealing structure. When the sealing ring 30 is subjected to external force, each protrusion 32 can share the force, avoiding local stress concentration, thereby improving the sealing ring 30's resistance to twisting and deformation and ensuring the continued effectiveness of the sealing function.

[0038] Preferably, in an optional embodiment, the sealing ring 30 has two annular grooves 31 on one side and three annular grooves 31 on the other side. Correspondingly, one protrusion 32 is provided on one side and two protrusions 32 on the other side. The different numbers of annular grooves 31 will cause differences in the contact pressure distribution on both sides of the sealing ring 30. During operation, this can promote a tighter and more uniform contact between the sealing ring 30 and the inner wall of the sealing groove 3. For example, the side with more annular grooves 31 may have more protrusions 32 in contact with the sealing groove 3, bearing the main sealing support role; while the side with fewer annular grooves 31 plays a supporting role in sealing and adjusting the pressure distribution, thereby optimizing the contact pressure of the entire sealing interface and improving the sealing effect.

[0039] Specifically, during drilling operations, the sealing ring 30 may be subjected to external forces from different directions, such as lateral forces generated by bearing eccentricity and the impact force of drilling fluid. The design of two annular grooves 31 on one side and three annular grooves 31 on the other side allows the sealing ring 30 to have different anti-interference capabilities in different directions. The side with more annular grooves 31 generally has stronger support and constraint capabilities, and can better resist external forces in larger directions; while the side with fewer annular grooves 31 is relatively flexible and can buffer and disperse external forces in smaller directions to a certain extent, thus enabling the sealing ring 30 as a whole to more effectively resist the interference of various complex external forces and maintain stable sealing performance.

[0040] In this application, the rotating section of the sealing ring 30 is rectangular, and an outer sealing part 4 is provided on the outer ring of the sealing ring 30. The outer sealing part 4 is an arc shape that protrudes radially outward based on the central axis of the sealing ring 30. An inner sealing part 5 is provided on the inner ring of the sealing ring 30. The inner sealing part 5 is an arc shape that protrudes radially inward based on the central axis of the sealing ring 30.

[0041] The arc-shaped outer seal 4 and the sealing groove 3 form an optimized contact interface. When the gear 2 oscillates eccentrically, the arc-shaped outer seal 4 can automatically adjust its contact position, forming a dynamically balanced contact pressure across the entire circumference, significantly improving its ability to prevent external mud intrusion. The inner seal 5 and the gear journal 10 form a second sealing barrier, working in conjunction with the outer seal 4 to significantly reduce grease leakage. The outer side of the sealing ring 30 bears the external high-pressure mud, while the inner side of the sealing ring 30 bears the internal grease pressure. The two are rigidly connected by a rectangular cross-section to form a pressure balance system.

[0042] In this embodiment, the protrusion 32 is specifically arc-shaped and flush with the outer sealing part 4 and the inner sealing part 5. This arc-shaped protrusion, flush with the outer and inner sealing parts 4 and 5, works synergistically to transform the originally discrete support structure into a seamless sealing band. When mating with the sealing groove 3, it avoids stress concentration issues. Under eccentric oscillation conditions of the roller wheel 2 bearing, the arc-shaped protrusion 32 can automatically adjust its contact position through elastic deformation, maintaining continuous contact. The flush design with the sealing part ensures that during changes in the eccentric angle, the protrusion 32, the outer sealing part 4, and the inner sealing part 5 can work together to maintain a stable sealing interface. Furthermore, this support structure is particularly suitable for high-deflection conditions. When the roller wheel 2 and the journal 10 of the roller wheel rotate relative to each other, multiple protrusions 32 can work together to form a dynamic adaptive contact in the sealing band. Even when the axial swing angle of the roller 2 is large, each protrusion 32 can automatically adjust the contact pressure distribution according to the actual displacement, avoiding the instantaneous failure problem caused by the complete detachment of a single contact surface under flexure in traditional metal end face seals. This characteristic allows this sealing device to maintain the advantage of radial sealing in adapting to large deflections while overcoming the reliability defects of metal seals under flexure conditions.

[0043] In this application, the annular groove 31 is also set as V-shaped, and the distance between the protrusion 32 formed between adjacent annular grooves 31 and the line connecting the inner and outer contours of the sealing ring 30 is 0~1mm.

[0044] The annular groove 31 is V-shaped, and the distance between the protrusion 32 between adjacent annular grooves 31 and the line connecting the inner and outer contours of the sealing ring 30 is 0~1mm. Through precise geometric design, an approximately continuous sealing contact zone is formed, achieving uniform pressure distribution and effective stress dispersion, thus reducing the maximum contact stress. The V-shaped annular groove 31 structure maintains its support advantages while optimizing the stress transmission path and avoiding the stress concentration problem of traditional right-angle annular grooves 31.

[0045] Example 2 Reference Figure 5 In this embodiment, the difference from Embodiment 1 is that the protrusion 32 is arc-shaped, and the contour of the protrusion 32 is lower than the contours of the outer sealing part 4 and the inner sealing part 5. The protrusion contour being lower than the outer sealing part and the inner sealing part creates a sealing structure for use under low pressure differential conditions. By appropriately weakening the supporting effect of the protrusion, the sealing structure is more prone to deformation under low pressure differential conditions, reducing the sealing contact pressure and thus reducing sealing heat generation, which is beneficial to improving the sealing life under low pressure differential conditions.

[0046] Example 3 Reference Figure 6In this embodiment, the difference from Embodiment 1 is that the protrusion 32 is cone-shaped and flush with the outer sealing portion 4 and the inner sealing portion 5. The cone-shaped protrusion 32 forms a line contact, and the stress is evenly distributed along the cone line, providing higher compressive stiffness and more stable contact characteristics, which is particularly suitable for high pressure differential conditions. Furthermore, the cone shape of the protrusion 32 and its flush with the outer sealing portion 4 and the inner sealing portion 5, through the formation of a continuous line contact sealing band, ensures that the contact stress is evenly distributed along the cone line, avoiding the central stress concentration problem that may occur with the arc-shaped protrusion 32, and further reducing the maximum contact stress.

[0047] Example 4 Reference Figure 7 In this embodiment, the difference from Embodiment 3 is that the protrusion 32 is cone-shaped, and the contour of the protrusion 32 is lower than the contours of the outer sealing part 4 and the inner sealing part 5. Under initial operating conditions, the outer sealing part 4 and the inner sealing part 5, as the main sealing surfaces, make initial contact first, forming a small initial contact area. When the roller bearing becomes eccentric due to wear or the drilling deflection increases, the cone-shaped protrusion 32 gradually participates in the contact. Its cone-shaped structure makes the contact stress evenly distributed along the cone line, avoiding the central stress concentration that may be generated by the arc-shaped protrusion 32. The structure of the protrusion 32 having a contour lower than the sealing part provides wear compensation space, significantly extending the effective working time of the sealing system.

[0048] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" 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; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0049] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A flat sealing device for a roller cone drill bit, characterized in that, It includes: Toothed palm (1), on which a toothed palm journal 10 is connected). A roller cone (2) is provided with a bearing hole (20), which is fitted onto the tooth bearing journal 10 to form a roller cone drill bit bearing; A sealing ring (30) is provided at the outer end of the bearing hole (20), and the sealing ring (30) is located in the sealing groove (3). The side of the sealing ring (30) is provided with multiple annular grooves (31), and a protrusion (32) is formed at the connection of two adjacent annular grooves (31).

2. The flat sealing device for a roller cone drill bit as described in claim 1, characterized in that: The rotating section of the sealing ring (30) is rectangular, and an outer sealing part (4) is provided on the outer ring of the sealing ring (30). The outer sealing part (4) is an arc shape that protrudes radially outward with the central axis of the sealing ring (30) as a reference. An inner sealing part (5) is provided on the inner ring of the sealing ring (30). The inner sealing part (5) is an arc shape that protrudes radially inward with the central axis of the sealing ring (30) as a reference.

3. The flat sealing device for a roller cone drill bit as described in claim 2, characterized in that: The protrusion (32) is arc-shaped and flush with the outer sealing part (4) and the inner sealing part (5).

4. A flat sealing device for a roller cone drill bit as described in claim 2, characterized in that: The protrusion (32) is arc-shaped, and the outline of the protrusion (32) is lower than the outline of the outer sealing part (4) and the inner sealing part (5).

5. A flat sealing device for a roller cone drill bit as described in claim 2, characterized in that: The protrusion (32) is cone-shaped and flush with the outer sealing part (4) and the inner sealing part (5).

6. A flat sealing device for a roller cone drill bit as described in claim 2, characterized in that: The protrusion (32) is cone-shaped, and the outline of the protrusion (32) is lower than the outline of the outer sealing part (4) and the inner sealing part (5).

7. A flat sealing device for a roller cone drill bit as described in claim 1, characterized in that: The annular groove (31) is V-shaped, and the distance between the protrusion (32) formed between adjacent annular grooves (31) and the line connecting the inner and outer contours of the sealing ring (30) is 0~1mm.

8. A flat sealing device for a roller cone drill bit as described in claim 7, characterized in that: The sealing ring (30) has at least two annular grooves (31) on each side.

9. A flat sealing device for a roller cone drill bit as described in claim 8, characterized in that: The sealing ring (30) has two annular grooves (31) on one side and three annular grooves (31) on the other side.

10. A flat sealing device for a roller cone drill bit as described in claim 1, characterized in that: The sealing ring (30) is made of polymer material.

Images