Composite bearing roller bit
By using a composite bearing structure and dynamic compensation sealing technology, the problem of poor sealing in traditional roller cone drill bits has been solved, achieving efficient lubrication and sealing effects, and improving the service life and operating efficiency of roller cone drill bits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2026-04-03
AI Technical Summary
Traditional roller cone drill bit sealing technology suffers from single-metal contact seals without dynamic compensation, rubber radial seals without self-lubricating design, and labyrinth non-contact seals that cannot completely block mud, resulting in poor sealing performance and affecting drill bit life and operating efficiency.
It adopts a composite bearing structure, including elastic slider and roller fit between the toothed wheel and the toothed shaft, combined with a dynamically compensated bimetallic seal structure and oil reservoir structure to provide grease supply and ensure the dynamic oil film and sealing function of the seal structure.
It improves the radial and axial load capacity of the bearing, prevents mud from entering the bearing cavity, extends the service life of the drill bit, improves operating efficiency, and reduces grease leakage and wear.
Smart Images
Figure CN224079074U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of drill bit technology, and in particular relates to a composite bearing roller cone drill bit. Background Technology
[0002] In fields such as oil drilling and geological exploration, roller cone drill bits are core rock-breaking tools, and the reliability of their bearing sealing system directly determines the lifespan and operational efficiency of the drill bit.
[0003] However, traditional sealing technologies for roller cone drill bits include single-metal contact seals, rubber radial seals, and labyrinth non-contact seals. Among them, single-metal contact seals have poor wear resistance, lack dynamic compensation, and the rigid installation of the sealing ring leads to the gap not closing after wear, resulting in a mud intrusion rate of 30%-50%. Rubber radial seals rely on external oil supply for lubrication, lack self-lubricating design, and require frequent shutdowns for grease injection. Labyrinth non-contact seals can only block particles >50μm, allowing fine particles to still intrude into the bearing cavity, failing to completely block mud, and resulting in a grease contamination rate >60%. Utility Model Content
[0004] The technical problem that this utility model needs to solve is that traditional roller cone drill bits have single metal contact seals without dynamic compensation, rubber radial seals without self-lubricating design, and labyrinth non-contact seals cannot completely block mud.
[0005] The technical solution adopted by this utility model for a composite bearing roller cone drill bit is as follows:
[0006] A composite bearing roller cone drill bit includes a die and a roller cone. The roller cone is connected to the die via a die shaft. A bearing cavity is formed between the roller cone and the die shaft. The roller cone is mounted on the die shaft via a composite bearing structure. A bimetallic seal structure with dynamic compensation function is provided on the outside of the bearing cavity for sealing the bearing cavity. An oil storage structure for storing grease and supplying oil to the bimetallic seal structure is provided inside the roller cone.
[0007] A further improvement of the present invention is that the composite bearing structure includes rollers and elastic sliders arranged alternately in an annular groove in the inner hole of the roller; wherein the elastic slider is arranged in an arc shape and is in contact with the roller shaft.
[0008] A further improvement of the above-mentioned technical solution of this utility model is that: the elastic slider is pre-pressed and embedded in the annular groove, and the inner radius of curvature of the elastic slider is smaller than the radius of the tooth palm axis, and the outer radius of curvature of the elastic slider is larger than the radius of the inner hole of the tooth wheel; wherein, the pre-pressing deformation of the elastic slider in the annular groove is 40%-60% of the limit deformation.
[0009] A further improvement of the above-mentioned technical solution of this utility model is that: the number of the elastic slider and the roller is 6-10, and the diameter of the roller is 0.1-0.3mm smaller than the radial thickness of the elastic slider.
[0010] A further improvement of the present invention is that the bimetallic sealing structure includes a dynamic sealing ring fixedly disposed in the inner hole of the toothed cone, and a static sealing ring sleeved on the toothed shaft and capable of floating along the axial direction of the toothed shaft; wherein, the static sealing ring is located below the dynamic sealing ring and fits against the dynamic sealing ring, and the static sealing ring always remains in contact with the dynamic sealing ring under the action of the compensation ring.
[0011] A further improvement of the above-mentioned technical solution of this utility model is that: the toothed shaft is provided with an installation groove for installing a static sealing ring and a compensation ring, and at least two guide keys are arranged on the side wall of the installation groove along the axial direction of the toothed shaft, and a keyway that cooperates with the guide keys is provided on the inner wall of the static sealing ring.
[0012] A further improvement of the present invention is that the oil storage structure includes an oil storage cavity opened inside the toothed gear above the toothed shaft for storing grease, and the oil storage cavity is connected to multiple lubrication channels extending toward the dynamic sealing ring; wherein, a plug is provided at the end of the oil storage cavity.
[0013] A further improvement of the above-mentioned technical solution of this utility model is that: the inner wall of the dynamic sealing ring is provided with an annular oil storage groove, and the inner wall of the dynamic sealing ring is also provided with a plurality of oil drain holes that are perpendicular to and connected to the annular oil storage groove. In addition, the dynamic sealing ring is also provided with a plurality of oil delivery holes that correspond one-to-one with a plurality of lubrication channels and are connected to the annular oil storage groove.
[0014] A further improvement of the above-mentioned technical solution of this utility model is that the lubrication channel is connected to the corresponding oil supply hole through a connector.
[0015] The technological advancements achieved by this utility model due to the adoption of the above technical solution are as follows:
[0016] The elastic slider in the composite bearing structure of this invention enables the roller cone and the roller shaft to fit together without clearance, thereby preventing excessive vibration of the roller cone when it is subjected to radial load. At the same time, the cooperation between the elastic slider and the roller improves the axial and radial load-bearing capacity of the roller cone drill bit. The oil storage structure of this invention can provide grease to the bimetallic seal structure during the drilling operation of the roller cone drill bit, thereby forming a dynamic oil film between the bimetallic seal structures for lubrication. Because the bimetallic seal structure of this invention has a dynamic compensation function, it can maintain its sealing function even after the bimetallic seal structure wears, preventing mud from entering the bearing cavity.
[0017] After the contact surfaces of the static and dynamic sealing rings wear down, the compensation ring pushes the static sealing ring to move along the tooth axis of the dynamic sealing ring, thereby keeping the static sealing ring in contact with the dynamic sealing ring at all times. This prevents gaps from forming between the static and dynamic sealing rings after wear, which would allow external slurry to enter the bearing cavity through the gaps.
[0018] In this invention, the guide key and keyway ensure that the static sealing ring can only move axially along the tooth shaft and cannot move radially along the tooth shaft, thereby ensuring that the sealing end faces of the static sealing ring and the dynamic sealing ring are always aligned.
[0019] When this utility model of roller cone drill bit is in use, the roller cone rotates at high speed and rubs against the formation, raising the temperature and increasing the pressure in the oil storage chamber. At the same time, the grease in the oil storage chamber expands due to heat, forcing the grease to enter the oil delivery hole through the lubrication channel. The grease flows along the oil delivery hole to the annular oil storage groove. The grease in the annular oil storage groove flows through the oil drain hole to the sealing end faces of the static sealing ring and the dynamic sealing ring. At the same time, under the action of centrifugal force, the grease can be evenly distributed on the sealing end faces of the static sealing ring and the dynamic sealing ring, forming a dynamic and uniform oil film.
[0020] In this invention, since multiple lubrication channels and oil delivery holes are provided, the lubrication function can still be maintained even if some lubrication channels or oil delivery holes are blocked. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of a composite bearing roller cone drill bit provided in an embodiment of the present invention;
[0022] Figure 2 This is a schematic cross-sectional view of the connection between the roller cone and the roller shaft of a composite bearing roller cone drill bit provided in this embodiment of the present invention;
[0023] Figure 3 This is a schematic diagram of the dynamic sealing ring of a composite bearing roller cone drill bit provided in an embodiment of the present invention;
[0024] Figure 4 This is a cross-sectional structural diagram of the tooth shaft of a composite bearing roller cone drill bit provided in an embodiment of this utility model.
[0025] In the attached diagram: 1. Toothed palm; 11. Toothed palm shaft; 12. Mounting groove; 13. Placement hole; 14. Shaft steel ball hole;
[0026] 2. Gear wheel;
[0027] 3. Composite bearing structure; 31. Roller; 32. Elastic slider;
[0028] 4. Bimetallic sealing structure; 41. Dynamic sealing ring; 411. Annular oil reservoir; 412. Oil drain hole; 413. Oil delivery hole; 42. Static sealing ring; 43. Compensation ring;
[0029] 5. Oil storage structure; 51. Oil storage chamber; 52. Lubrication channel; 53. Block;
[0030] 6. Circular groove. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of this utility model.
[0032] refer to Figure 1 As can be seen, in this embodiment, the roller cone drill bit includes a toothed palm 1, and a toothed palm shaft 11 is fixedly connected to the top of the toothed palm 1. The axis of the toothed palm shaft 11 forms an angle of 30°-60° with the axis of the toothed palm 1. A roller cone 2 is rotatably connected to the toothed palm shaft 11, and a bearing cavity is formed between the roller cone 2 and the toothed palm shaft 11.
[0033] In this invention, the toothed wheel 2 is connected to the toothed shaft 11 via a composite bearing structure 3. (Reference) Figure 2 As can be seen, in this embodiment, the composite bearing structure 3 includes rollers 31 and elastic sliders 32 arranged alternately within the inner hole of the roller cone. Specifically, the inner hole of the roller cone has an annular groove, and the rollers 31 and elastic sliders 32 are arranged alternately within the annular groove. In this embodiment, the elastic sliders 32 are arranged in an arc shape. The elastic sliders 32 are pre-pressed into the annular groove, and the inner radius of curvature of the elastic sliders 32 is smaller than the radius of the toothed shaft 11, while the outer radius of curvature of the elastic sliders 32 is larger than the radius of the inner hole of the roller cone. The pre-press deformation of the elastic sliders 32 within the annular groove is 40%-60% of the ultimate deformation, preferably 50%. When the elastic sliders 32 are pre-pressed into the annular groove, the radial thickness of the elastic sliders 32 after deformation is the same as the diameter of the rollers 31. In this embodiment, the number of each of the rollers 31 and elastic sliders 32 is 6-10, preferably 8, and the diameter of the rollers 31 is 0.1-0.3 mm smaller than the radial thickness of the elastic sliders 32, preferably 0.2 mm. In this embodiment, the elastic slider 32 can be made of spring steel. At the same time, the inner and outer walls of the elastic slider 32 are coated with a protective layer (such as copper-based alloy). On the one hand, it can protect the elastic slider 32, and on the other hand, it can reduce the friction between the elastic slider 32 and the toothed wheel 2.
[0034] In this embodiment, the composite bearing structure 3 consists of rollers 31 and elastic sliders 32 arranged alternately. The rigid bearing capacity of the rollers 31 and the flexible preload of the elastic sliders 32 work together. At this time, the radial thickness of the elastic sliders 32 after deformation is the same as the diameter of the rollers 31. Therefore, the elastic sliders 32 and rollers 31 simultaneously contact the gear 2 and the gear shaft 11. When the gear 2 rotates at high speed, the rollers 31 in the composite bearing structure 3 mainly bear the radial load on the gear 2, dispersing the pressure during rotation and reducing localized wear. When the gear 2 is subjected to external impact, the elastic sliders 32 generate a reverse elastic force due to preload deformation, absorbing vibration energy and preventing vibration caused by the expansion of the bearing cavity clearance.
[0035] When the roller cone drill bit of this utility model rotates, the roller cone 2 and the tooth bearing shaft 11 are stably supported by the roller 31, and the elastic slider 32 continuously provides preload, forming a gapless fit; when the roller cone drill bit encounters a hard stratum impact, the elastic slider 32 undergoes slight deformation to alleviate the instantaneous impact force, and the roller 31 maintains the bearing rigidity. The synergy between the roller 31 and the elastic slider 32 can improve the service life of the composite bearing structure 3 of this utility model.
[0036] In this invention, the bearing cavity is located on the outside of the composite bearing structure 3 and is further provided with a bimetallic seal structure 4 to prevent external mud from entering the bearing cavity. This bimetallic seal structure 4 has a dynamic compensation function. (Reference) Figure 2 As can be seen, the bimetallic sealing structure 4 in this embodiment includes a dynamic sealing ring 41 located in the inner bore of the gear 2. The dynamic sealing ring 41 rotates together with the gear 2. Specifically, the dynamic sealing ring 41 is embedded in the inner bore of the gear 2 to form an interference fit with the inner bore of the gear 2. For example, the gear 2 is heated to 150-200°C to temporarily expand the diameter of the inner bore of the gear 2. Then, the dynamic sealing ring 41 is pressed into the heated inner bore of the gear 2 at room temperature. After cooling, the inner bore of the gear 2 and the dynamic sealing ring 41 form a tight interference fit.
[0037] To prevent the dynamic sealing ring 41 from slipping during the rotation of the gear 2, a locating key can be set on the inner hole of the gear, and a keyway that matches the locating key can be machined on the outer wall of the dynamic sealing ring 41. The cooperation between the locating key and the keyway can prevent the dynamic sealing ring 41 from slipping during the rotation of the gear 2.
[0038] In this embodiment, the outer side of the dynamic sealing ring 41 is coated with a wear-resistant layer (such as a nickel-based tungsten carbide coating) to reduce its wear risk.
[0039] In this embodiment, a static sealing ring 42 is fitted to the outer side of the dynamic sealing ring 41. The static sealing ring 42 is sleeved on the tooth bearing shaft 11 and can float along the axial direction of the tooth bearing shaft 11. A compensation ring 43 is provided on the outer side of the static sealing ring 42 to push it to float. Simultaneously, a lubricating layer (such as a diamond coating) is coated on the outer side of the static sealing ring 42 to further reduce the coefficient of friction and reduce heat generation. Specifically, for example... Figure 4 As shown, an annular mounting groove 12 is provided on the toothed shaft 11. The static sealing ring 42 is fitted inside the mounting groove 12 and located outside the dynamic sealing ring 41, and is in close contact with the dynamic sealing ring 41. In this embodiment, at least two guide keys are arranged on the side wall of the mounting groove 12 along the axial direction of the toothed shaft 11. The inner wall of the static sealing ring 42 is provided with a keyway that cooperates with the guide keys. Through the mutual cooperation of the guide keys and the keyway, it can be ensured that the static sealing ring 42 can only move along the axial direction of the toothed shaft 11 and cannot move along the radial direction of the toothed shaft 11, thereby ensuring that the sealing end faces of the static sealing ring 42 and the dynamic sealing ring 41 are always aligned.
[0040] Continue to refer to Figure 4 A rubber compensation ring 43 is fitted inside the mounting groove 12 on the outer side of the static sealing ring 42. During initial installation, the rubber compensation ring 43 has a certain deformation, specifically 50%-80% of its limit deformation, preferably 65%, thereby generating an initial axial preload on the static sealing ring 42, pushing it tightly against the end face of the dynamic sealing ring 41. In this embodiment, the rubber compensation ring 43 can be a rubber ring with a compression set ≤15% to ensure its long-term sealing compensation capability. Simultaneously, the radial cross-sectional width of the compensation ring 43 matches the radial cross-sectional width of the static sealing ring 42 to ensure uniform pressure distribution.
[0041] When the rotary drill bit of this utility model is in use, after the sealing surfaces of the static sealing ring 42 and the dynamic sealing ring 41 are worn, the compensation ring 43 pushes the static sealing ring 42 to move along the tooth bearing shaft 11 toward the dynamic sealing ring 41, so that the static sealing ring 42 always keeps in contact with the dynamic sealing ring 41, preventing the static sealing ring 42 and the dynamic sealing ring 41 from having gaps after the contact surfaces of the static sealing ring 42 and the dynamic sealing ring 41 are worn, and allowing external mud to enter the bearing cavity through the gaps.
[0042] In this invention, the roller cone 2 is further provided with an oil storage structure 5, which can provide grease to the bimetallic seal structure 4 during the drilling of the roller cone 2. (Reference) Figure 2 and Figure 3As can be seen, in this embodiment, the oil storage structure 5 includes an oil storage cavity 51 located above the tooth bearing shaft 11 within the toothed gear 1. This oil storage cavity 51 stores lubricating grease. Simultaneously, a plug 53 is provided at the end of the oil storage cavity 51, which seals the oil storage cavity 51 to prevent lubricating grease leakage. Specifically, the plug 53 can be threadedly connected to the oil storage cavity 51. Furthermore, to facilitate rotation of the plug 53, a cross-shaped hole for cooperating with a screwdriver can be provided at the center of the outer end of the plug 53.
[0043] In this embodiment, the oil storage cavity 51 is connected to multiple lubrication channels 52 extending toward the moving sealing ring 41.
[0044] For better lubrication, refer to Figure 2 and Figure 3 It is known that the inner wall of the dynamic sealing ring 41 has an annular oil reservoir 411, and the inner wall of the dynamic sealing ring 41 also has multiple oil drain holes 412 that are perpendicular to and connected to the annular oil reservoir 411. Furthermore, the dynamic sealing ring 41 also has multiple oil delivery holes 413 that correspond one-to-one with the multiple lubrication channels 52 and are connected to the annular oil reservoir 411. When the dynamic sealing ring 41 is installed in the inner bore of the gear with an interference fit, the lubrication channels 52 and the oil delivery holes 413 are connected one-to-one. Specifically, the lubrication channels 52 can be connected to the corresponding oil delivery holes 413 through connectors, which can be made of rubber or soft plastic.
[0045] When this utility model of roller cone drill bit is in use, the roller cone 2 rotates at high speed and heats up due to friction with the formation, increasing the pressure in the oil storage chamber 51. At the same time, the grease in the oil storage chamber 51 expands due to heat, forcing the grease to enter the oil delivery hole 413 through the lubrication channel. The grease flows along the oil delivery hole 413 to the annular oil storage groove 411. The grease in the annular oil storage groove 411 flows through the oil drain hole 412 to the sealing end faces of the static sealing ring 42 and the dynamic sealing ring 41. At the same time, under the action of centrifugal force, the grease can be evenly distributed on the sealing end faces of the static sealing ring 42 and the dynamic sealing ring 41, forming a dynamic and uniform oil film.
[0046] In this invention, the bearing cavity is also fitted with a ring of steel balls that fix the toothed wheel 2 and the toothed shaft 11 together. (Reference) Figure 2 and Figure 4 As can be seen, in this embodiment, the steel ball is located inside the composite bearing structure 3. Specifically, the inner wall of the roller 2 is provided with an annular roller ball hole for placing the steel ball corresponding to the position of the steel ball, and the outer wall of the roller shaft 11 is provided with an annular shaft ball hole 14 for placing the steel ball corresponding to the position of the steel ball. When the roller 2 and the roller shaft 11 are connected together, the roller ball hole and the shaft ball hole cooperate to form an annular groove 6, and the steel ball is located in the annular groove 6.
[0047] To facilitate the placement of the steel ball into the upper annular groove 6, a placement hole 13 communicating with the steel ball hole 14 is provided in the tooth bearing shaft 11. This placement hole 13 extends into and penetrates the tooth bearing 1. Simultaneously, to prevent foreign objects from entering the tooth bearing 1 through the placement hole 13 during use, a plug pin is interference-fitted to the outer end of the placement hole 13. Specifically, the plug pin can be inserted into the placement hole 13. To prevent the plug pin from falling out during the rotation of the tooth bearing 2, after the plug pin is inserted into the placement hole 13, it can be welded together with the tooth bearing 2.
[0048] The working principle of this roller cone drill bit, applicable to both soft and hard formations, is as follows:
[0049] When this utility model roller cone drill bit is in use, the roller cone 2 rotates at high speed and rubs against the formation, raising its temperature. The pressure in the oil storage chamber 51 increases, and the grease in the oil storage chamber 51 expands due to heat. At the same time, under the action of centrifugal force, the grease in the oil storage chamber 51 is forced to enter the oil delivery hole 413 through the lubrication channel. The grease flows along the oil delivery hole 413 to the annular oil storage groove 411. The grease in the annular oil storage groove 411 flows through the oil drain hole 412 to the sealing end faces of the static sealing ring 42 and the dynamic sealing ring 41. At the same time, under the action of centrifugal force, the grease can be evenly distributed on the sealing end faces of the static sealing ring 42 and the dynamic sealing ring 41, forming a dynamic and uniform oil film.
[0050] When the contact surfaces of the static sealing ring 42 and the dynamic sealing ring 41 wear down, the compensation ring 43 pushes the static sealing ring 42 to move along the toothed shaft 11 toward the dynamic sealing ring 41, so that the static sealing ring 42 always keeps in contact with the dynamic sealing ring 41, preventing gaps from appearing between the static sealing ring 42 and the dynamic sealing ring 41 after the contact surfaces of the static sealing ring 42 and the dynamic sealing ring 41 wear down, allowing external mud to enter the bearing cavity through the gaps.
[0051] In the above embodiments, this utility model provides a composite bearing roller cone drill bit. The elastic slider in the composite bearing structure of this utility model enables the roller cone and the roller shaft to fit together without clearance, thereby preventing excessive vibration amplitude of the roller cone when it is subjected to radial load. At the same time, the mutual cooperation between the elastic slider and the roller can improve the axial and radial load-bearing capacity of the roller cone drill bit of this application. The oil storage structure of this utility model can provide grease to the bimetallic seal structure during the drilling operation of the roller cone drill bit, thereby forming a dynamic oil film between the bimetallic seal structures for lubrication. In this utility model, because the bimetallic seal structure has a dynamic compensation function, it can always maintain the sealing function after the bimetallic seal structure is worn, preventing mud from entering the bearing cavity.
[0052] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention. The technical content for which protection is sought in the present invention has been fully described in the claims.
Claims
1. A composite bearing roller cone drill bit, comprising a die (1) and a roller cone (2), wherein the roller cone (2) is connected to the die (1) via a die shaft (11), and a bearing cavity is formed between the roller cone (2) and the die shaft (11), characterized in that: The toothed wheel (2) is mounted on the toothed shaft (11) via the composite bearing structure (3). The bearing cavity is located on the outside of the composite bearing structure (3) and is provided with a bimetallic seal structure (4) with dynamic compensation function for sealing the bearing cavity. The toothed wheel (2) is provided with an oil storage structure (5) for storing grease and supplying oil to the bimetallic seal structure (4).
2. The composite bearing roller cone drill bit according to claim 1, characterized in that: The composite bearing structure (3) includes rollers (31) and elastic sliders (32) arranged alternately in the annular groove of the inner hole of the toothed wheel; wherein the elastic sliders (32) are arranged in an arc shape and are in contact with the toothed wheel shaft (11).
3. The composite bearing roller cone drill bit according to claim 2, characterized in that: The elastic slider (32) is pre-pressed into the annular groove, and the inner radius of curvature of the elastic slider (32) is smaller than the radius of the tooth palm shaft (11), and the outer radius of curvature of the elastic slider (32) is larger than the radius of the inner hole of the tooth wheel; wherein, the pre-pressed deformation of the elastic slider (32) in the annular groove is 40%-60% of the limit deformation.
4. A composite bearing roller cone drill bit according to claim 3, characterized in that: The number of elastic sliders (32) and rollers (31) is 6-10, and the diameter of the rollers (31) is 0.1-0.3 mm smaller than the radial thickness of the elastic sliders (32).
5. A composite bearing roller cone drill bit according to claim 1, characterized in that: The bimetallic sealing structure (4) includes a dynamic sealing ring (41) fixedly disposed in the inner hole of the toothed cone, and a static sealing ring (42) sleeved on the toothed shaft (11) and capable of floating along the axial direction of the toothed shaft (11); wherein, the static sealing ring (42) is located below the dynamic sealing ring (41) and fits against the dynamic sealing ring (41), and the static sealing ring (42) always remains in contact with the dynamic sealing ring (41) under the action of the compensation ring (43).
6. A composite bearing roller cone drill bit according to claim 5, characterized in that: The toothed shaft (11) is provided with a mounting groove (12) for installing a static sealing ring (42) and a compensation ring (43). The side wall of the mounting groove (12) is provided with at least two guide keys along the axial direction of the toothed shaft (11). The inner wall of the static sealing ring (42) is provided with a keyway that cooperates with the guide keys.
7. A composite bearing roller cone drill bit according to any one of claims 1-6, characterized in that: The oil storage structure (5) includes an oil storage cavity (51) located above the tooth shaft (11) inside the toothed wheel (2) for storing grease. The oil storage cavity (51) is connected to multiple lubrication channels (52) extending toward the dynamic sealing ring (41). A plug (53) is provided at the end of the oil storage cavity (51).
8. A composite bearing roller cone drill bit according to claim 7, characterized in that: The inner wall of the dynamic sealing ring (41) is provided with an annular oil reservoir (411). At the same time, the inner wall of the dynamic sealing ring (41) is also provided with a plurality of oil drain holes (412) that are perpendicular to and connected to the annular oil reservoir (411). The dynamic sealing ring (41) is also provided with a plurality of oil delivery holes (413) that correspond one-to-one with the plurality of lubrication channels (52) and are connected to the annular oil reservoir (411).
9. A composite bearing roller cone drill bit according to claim 8, characterized in that: The lubrication channel (52) is connected to the corresponding oil supply hole (413) through a connector.