Drilling tool thrust bearing structure for deep well oil exploitation

Abstract

The invention provides a drilling tool thrust bearing structure for deep well oil exploitation, and relates to the technical field of bearing structures, the drilling tool thrust bearing structure comprises a static ring assembly, a movable ring assembly and a ball assembly, the static ring assembly comprises an outer static ring, a lower-section raceway is formed in an inner ring of the outer static ring, the movable ring assembly comprises an inner movable ring, and a lower-section raceway is formed in an outer ring of the inner movable ring; the outer side wall of the inner moving ring is provided with an upper-section raceway, the ball assembly comprises a large ball, a small ball, a large elastic retainer and a small elastic retainer, and the large ball and the small ball are both located at the lower-section raceway and the upper-section raceway between the static ring assembly and the moving ring assembly. A rigidity-adjustable ball array is formed by connecting a large elastic retainer, a small elastic retainer and an elastic beam, and accurate positioning of balls is ensured through a double-curvature curved surface raceway; degradable polymer capsules are arranged to be filled with high-temperature lubricating grease, and oil is supplemented as required according to ball abrasion; the inner moving ring is matched with the shaft through a concave-convex spherical surface, the axis angle is automatically adjusted to compensate the deflection amount, and edge contact abrasion is avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bearing structure, more specifically, relates to a drill tool thrust bearing structure for deep well oil exploitation. BACKGROUND

[0002] In the harsh working environment involving mud medium such as oil drilling and mining, traditional bearings face many severe challenges and are difficult to meet the actual production needs.

[0003] From the perspective of service life, in the complex and corrosive medium of mud, the cycle life of traditional bearings is relatively short. Solid particles in the mud can easily enter the bearing interior, exacerbating the wear between the balls and the raceways, leading to premature failure of the bearing. Frequent replacement of bearings not only increases production costs but also seriously affects production efficiency.

[0004] In terms of load bearing, the ability of traditional bearings to cope with axial load is limited. When encountering sudden load changes such as sticking, the contact stress of the balls inside the bearing will increase sharply, easily causing excessive wear and even damage to the balls and raceways, and cannot effectively guarantee the stable operation of the equipment. Moreover, traditional bearings lack an effective load sharing mechanism and are difficult to adjust the load bearing capacity flexibly under different working conditions, limiting their application in various working conditions.

[0005] Friction torque is also a major problem of traditional bearings. Higher friction torque will cause difficulty in starting and increase energy consumption, especially in light load conditions, unnecessary high friction torque will reduce the overall efficiency of the equipment. In heavy load conditions, traditional bearings are also difficult to provide sufficient stiffness to bear large loads, and cannot meet the demand for high load capacity in some special working scenarios.

[0006] In terms of lubrication management, traditional bearings usually use pre-applied grease, but in actual use, they cannot supplement oil as needed according to the wear of the bearing. With the wear of the bearing, the grease is gradually consumed and cannot be replenished in time, leading to a decrease in lubrication effect and further exacerbating wear, forming a vicious cycle.

[0007] In addition, in actual application scenarios, the slight deviation of the shaft is difficult to avoid. In oil drilling, for example, due to irregular well walls and other reasons, the shaft may be deflected. Traditional bearings lack the ability to automatically adjust the axis angle, and the deflection of the shaft can easily cause edge contact wear between the inner and outer rings, greatly shortening the service life of the bearing.

[0008] In summary, the existing bearing technology in the mud medium environment has many problems such as short cycle life, insufficient load bearing capacity, unreasonable friction torque, inconvenient lubrication management, and poor adaptability to shaft deflection, which cannot meet the requirements of modern industry for high performance, long life and high reliability of bearings in harsh working conditions. SUMMARY

[0009] In order to solve the above technical problems, the present application provides a deep well drilling tool thrust bearing structure to solve the above problems.

[0010] The deep well drilling tool thrust bearing structure comprises a static ring assembly, a dynamic ring assembly and a ball assembly, the static ring assembly comprises an outer static ring, the inner ring of the outer static ring is provided with a lower segment raceway, the dynamic ring assembly comprises an inner dynamic ring, the outer sidewall of the inner dynamic ring is provided with an upper segment raceway, the ball assembly comprises large balls, small balls, large elastic retainers and small elastic retainers, the large balls and the small balls are located at the lower segment raceway and the upper segment raceway between the static ring assembly and the dynamic ring assembly, each large elastic retainer is sleeved outside the large ball, each small elastic retainer is sleeved outside the small ball, and an elastic beam is connected between each large elastic retainer and small elastic retainer.

[0011] Preferably, at least two annular N-pole permanent magnets and annular S-pole permanent magnets are embedded outside the outer static ring, and the annular N-pole permanent magnets and the annular S-pole permanent magnets are alternately distributed, a magnetically conductive alloy sheet is installed in the inner dynamic ring, and the magnetically conductive alloy sheet is installed at an axially corresponding position of the inner dynamic ring, and the magnetically conductive alloy sheet and the annular N-pole permanent magnets and the annular S-pole permanent magnets axially face the arrayed regions.

[0012] Preferably, the volume of the small balls is smaller than that of the large balls, and the large balls and the small balls are alternately distributed, the upper segment raceway extends from the inner dynamic ring to the central shaft direction, and has a smaller radius corresponding to the small balls, and the lower segment raceway extends from the outer static ring to the central shaft direction, and has a larger radius corresponding to the large balls.

[0013] Preferably, the large elastic retainers, the small elastic retainers and the elastic beam are integrally formed in a wave shape, a connecting frame is fixedly installed between the large elastic retainers and the small elastic retainers, the connecting frame is located above the elastic beam, a capsule is embedded and fixedly installed above the elastic beam, the middle part of the connecting frame is an upward arc segment, an elastic sheet is fixedly installed below the arc segment, and a conical spike is fixedly installed in the middle part below the arc segment of the connecting frame.

[0014] Preferably, at least two concave spherical surfaces are formed in the inner part of the inner dynamic ring, a shaft is arranged in the inner part of the inner dynamic ring, at least two convex spherical surfaces are fixedly installed on the surface of the shaft, and each convex spherical surface can be inserted into the corresponding concave spherical surface.

[0015] Compared with the prior art, the present application has the following beneficial effects: The bearing of the application has long cycle life under mud medium by adopting specific ball assembly matching with raceway, connection mode of inner moving ring and shaft and black phosphating treatment of retainer, utilizes axial magnetic suspension force field to bear part of axial load, reduces ball contact stress and wear rate, triggers mechanical contact protection magnet when load mutation occurs, and realizes light load small ball preferential load reduction of friction torque, heavy load large and small ball common load stiffness improvement through alternating distribution of large and small balls combined with wavy elastic connection structure; through the connection of large elastic retainer, small elastic retainer and elastic beam, a "stiffness adjustable" ball array is formed, and the double curvature surface raceway ensures accurate positioning of the ball; the degradable polymer capsule is filled with high temperature lubricating grease, and the lubricating grease is supplemented according to the wear of the ball; the inner moving ring and the shaft are matched through concave-convex spherical surfaces, the axis angle is automatically adjusted to compensate the deflection, and the edge contact wear is avoided.

[0016] In the application, the inside of the inner moving ring is provided with a shaft, the outer side wall of the inner moving ring is provided with an upper segment raceway, the ball assembly includes large balls, small balls, large elastic retainers and small elastic retainers, the large balls and the small balls are located at the lower segment raceway and the upper segment raceway between the static ring assembly and the moving ring assembly, each large elastic retainer is sleeved outside the large ball, each small elastic retainer is sleeved outside the small ball, and an elastic beam is connected between each large elastic retainer and small elastic retainer, in use, the shaft is installed in the inner moving ring, the shaft drives the inner moving ring to rotate, the inner moving ring slides on the surface of the large ball and the small ball, and the large ball and the small ball are simultaneously driven to rotate, the bearing has a cycle life of ≥ under mud medium, and the retainer is black phosphated as a whole.

[0017] In the application, a magnetically conductive alloy sheet is installed in the inner moving ring and corresponds to the axial position of the inner moving ring, the magnetically conductive alloy sheet and the axially opposite areas of the annular N-pole permanent magnet and the annular S-pole permanent magnet array, in use, form an axial magnetic suspension force field, in normal operation, the magnetic suspension force bears 30% of the axial load, the ball contact stress is reduced by 30%, and the wear rate is reduced by 50%, when the load is suddenly changed (such as sticking), the magnetic gap is reduced to a critical value (≤0.2mm), the mechanical contact is triggered, the magnet is prevented from being directly impacted and failed, the annular N-pole permanent magnet and the annular S-pole permanent magnet adopt samarium-cobalt permanent magnet material (residual magnetism ≥1.2T), and the surface is plated with nickel-phosphorus alloy for corrosion resistance; the magnetically conductive sheet and the inner moving ring are connected through a flexible hinge, allowing ±1° deflection, and adapting to the slight deviation of the shaft.

[0018] In the application, the large elastic retainer, the small elastic retainer and the elastic beam are integrally formed in a wave shape, the volume of the small ball is smaller than that of the large ball (for example, the large ball is 25 mm in diameter and the small ball is 20 mm in diameter, which are arranged alternately), the large elastic retainer, the small elastic retainer and the elastic beam are connected to form a "stiffness-adjustable" ball array, and the large ball and the small ball are alternately distributed, the upper segment raceway extends from the inner moving ring to the center axis direction, the radius is small, and the upper segment raceway corresponds to the small ball, the lower segment raceway extends from the outer static ring to the center axis direction, the radius is large, and the lower segment raceway corresponds to the large ball, in use: in light load working condition, the small ball preferentially contacts the bearing to reduce the friction torque (the starting torque is reduced by 40%); in heavy load working condition, the large ball is pressed to sink and jointly bears with the small ball, the overall stiffness is improved by 60%, and the demand of ≥25T axial load is met; the large elastic retainer, the small elastic retainer and the elastic beam are connected in a wave-shaped elastic beam structure, and the axial displacement difference between the large ball and the small ball is allowed to be ≤0.5 mm; the lower segment raceway and the upper segment raceway are double curvature surfaces (the curvature radius of the upper segment raceway matches the small ball, and the lower segment raceway matches the large ball), so that the different diameter large ball and the small ball can be accurately positioned.

[0019] In the application, the elastic beam is embedded and fixedly installed with a capsule above, the middle part of the connecting frame is an upward arc segment, the arc segment is fixedly installed with an elastic sheet below, and the middle part below the arc segment of the connecting frame is fixedly installed with a conical spike, in use, the capsule is filled with high-temperature lubricating grease, the capsule itself is a degradable polymer, in the initial state, the capsule is in a sealed state, the lubricating grease is not released, and early aging of the grease is avoided.

[0020] In the application, when the wear of the large ball and the small ball is ≥0.1 mm, the large elastic retainer and the small elastic retainer are deformed to pull the elastic beam, at this time, the connecting frame is subjected to the pulling force of the large elastic retainer and the small elastic retainer, the connecting frame is subjected to the force to drive the arc segment at the top to deviate downward, the elastic sheet itself has a certain elasticity and can keep the arc segment at the top of the connecting frame, after the elastic sheet is subjected to the pulling force, the elastic sheet drives the arc segment to gradually flatten, and simultaneously drives the conical spike to pierce the capsule, the capsule shell is broken to release the lubricating grease, and the oil is supplemented as needed.

[0021] In the application, the inside of the inner moving ring is provided with at least two concave spherical surfaces, and the surface of the shaft is fixedly installed with at least two convex spherical surfaces, each convex spherical surface can be inserted into the concave spherical surface, when the shaft is deflected due to irregular well wall, the convex spherical surface slides in the concave spherical surface, the shaft line angle is automatically adjusted, the deflection amount is compensated (the maximum allowed angle is ≤1.5°), and edge contact wear of the inner moving ring and the outer static ring due to the shaft line deviation is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic view of the outer static ring structure of the application; Figure 2 is a schematic view of the overall structure of the static ring assembly of the application; Figure 3 is the schematic diagram of the inner moving ring structure of the present application; Figure 4 is the schematic diagram of the overall structure of the ball assembly of the present application; Figure 5 is the schematic diagram of the structure of the large elastic retainer of the present application; Figure 6 is the schematic diagram of the structure of the connecting frame of the present application; Figure 7 is the schematic diagram of the structure of the shaft of the present application; Figure 8 is the schematic diagram of the overall structure of the moving ring assembly of the present application.

[0023] In the figure, the corresponding relationship between the component names and the figure numbers is as follows: 1, static ring assembly; 11, outer static ring; 12, lower segment raceway; 13, annular N-pole permanent magnet; 14, annular S-pole permanent magnet; 2, moving ring assembly; 21, inner moving ring; 22, upper segment raceway; 23, concave spherical surface; 24, shaft; 25, convex spherical surface; 3, ball assembly; 31, large ball; 32, small ball; 33, large elastic retainer; 34, small elastic retainer; 35, elastic beam; 36, capsule; 37, connecting frame; 38, elastic sheet; 39, conical spike. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0025] Please refer to Figures 1-8 , the present application provides a kind of deep well oil exploitation with drill tool thrust bearing structure, including static ring assembly 1, moving ring assembly 2 and ball assembly 3, static ring assembly 1 includes outer static ring 11, the inner ring of outer static ring 11 is set with lower segment raceway 12, moving ring assembly 2 includes inner moving ring 21, the inside of inner moving ring 21 is provided with shaft 24, the outer side wall of inner moving ring 21 is set with upper segment raceway 22, ball assembly 3 includes large ball 31, small ball 32, large elastic retainer 33 and small elastic retainer 34, large ball 31 and small ball 32 are located at lower segment raceway 12 and upper segment raceway 22 between static ring assembly 1 and moving ring assembly 2, each large elastic retainer 33 is all set in the outside of large ball 31, each small elastic retainer 34 is all set in the outside of small ball 32, each large elastic retainer 33 and small elastic retainer 34 are all connected with elastic beam 35, when using, shaft 24 is installed in the inside of inner moving ring 21, shaft 24 operates and drives inner moving ring 21 to rotate, inner moving ring 21 rotates and slides on the surface of large ball 31 and small ball 32, simultaneously will drive large ball 31 and small ball 32 to rotate, the bearing under mud medium cycle life ≥ , the overall black phosphating treatment of sleeve ring.

[0026] The outer static ring 11 is embedded with at least two annular N-pole permanent magnets 13 and annular S-pole permanent magnets 14, and the annular N-pole permanent magnets 13 and annular S-pole permanent magnets 14 are alternately distributed, the inner moving ring 21 is internally mounted with a magnetic conductive alloy sheet, and the magnetic conductive alloy sheet is mounted at an axially corresponding position of the inner moving ring 21, the magnetic conductive alloy sheet and the annular N-pole permanent magnets 13 and annular S-pole permanent magnets 14 array axially opposite regions, and in use, an axial magnetic suspension force field is formed, in normal operation, the magnetic suspension force bears 30% of the axial load, the ball contact stress is reduced by 30%, the wear rate is reduced by 50%, and when the load suddenly changes (such as a stuck drill), the magnetic gap is reduced to a critical value (≤0.2mm), triggering mechanical contact, avoiding direct impact failure of the magnet.

[0027] Structural design: The annular N-pole permanent magnets 13 and annular S-pole permanent magnets 14 use samarium-cobalt permanent magnet material (residual magnetism ≥1.2T), and the surface is plated with nickel-phosphorus alloy for corrosion protection; the magnetic conductive sheet and the inner moving ring 21 are connected through a flexible hinge, allowing ±1° deflection to adapt to the slight deviation of the shaft.

[0028] The large elastic retainer 33, small elastic retainer 34 and elastic beam 35 are formed in a wave shape, the volume of the small balls 32 is smaller than that of the large balls 31 (such as large balls 31 with a diameter of 25mm and small balls 32 with a diameter of 20mm arranged alternately), connected through the large elastic retainer 33, small elastic retainer 34 and elastic beam 35, forming a "stiffness-adjustable" ball array, and the large balls 31 and small balls 32 are alternately distributed, the upper segment raceway 22 extends from the inner moving ring 21 to the center axis direction, with a smaller radius corresponding to the small balls 32, and the lower segment raceway 12 extends from the outer static ring 11 to the center axis direction, with a larger radius corresponding to the large balls 31, and in use: Light load condition: The small balls 32 preferentially contact the load, reducing the friction torque (the starting torque is reduced by 40%).

[0029] Heavy load condition: The large balls 31 sink under pressure and jointly bear the load with the small balls, the overall stiffness is improved by 60%, meeting the demand of ≥25T axial load.

[0030] The large elastic retainer 33, small elastic retainer 34 and elastic beam 35 are connected in a wave-shaped elastic beam structure, allowing the large balls and small balls to have an axial displacement difference of ≤0.5mm.

[0031] The lower segment raceway 12 and upper segment raceway 22 are double curvature surfaces (the upper segment raceway 22 has a curvature radius matching the small balls, and the lower segment raceway 12 matches the large balls), ensuring that the different diameter large balls 31 and small balls 32 can be accurately positioned.

[0032] The connecting frame 37 is fixedly installed between the large elastic retainer 33 and the small elastic retainer 34, is located above the elastic beam 35, the capsule 36 is embedded and fixedly installed above the elastic beam 35, the middle part of the connecting frame 37 is an upward arc segment, the elastic sheet 38 is fixedly installed below the arc segment, the conical spike 39 is fixedly installed in the middle part below the arc segment of the connecting frame 37, in use, the capsule 36 is filled with high-temperature lubricating grease, the capsule 36 is a degradable polymer, in the initial state, the capsule 36 is in a sealed state, the lubricating grease is not released, and early aging of grease is avoided; When the wear amount of the large ball 31 and the small ball 32 is greater than or equal to 0.1 mm, the large elastic retainer 33 and the small elastic retainer 34 are deformed, the elastic beam 35 is pulled, the connecting frame 37 is subjected to the pulling force of the large elastic retainer 33 and the small elastic retainer 34, the top arc segment of the connecting frame 37 is offset downward under the action of the force, the elastic sheet 38 has a certain elasticity and can keep the top arc segment of the connecting frame 37, after the elastic sheet 38 is subjected to the pulling force, the elastic sheet 38 drives the arc segment to gradually flatten, and drives the conical spike 39 to pierce the capsule 36, the capsule 36 shell is broken to release the lubricating grease, and the oil is supplemented on demand.

[0033] The inner moving ring 21 is internally provided with at least two concave spherical surfaces 23, and the surface of the shaft 24 is fixedly provided with at least two convex spherical surfaces 25, each convex spherical surface 25 can be inserted into the concave spherical surface 23, when the shaft 24 is deflected due to irregular well wall, the convex spherical surface 25 slides in the concave spherical surface 23, automatically adjusts the axis angle, compensates the deflection amount (the maximum allowable angle is less than or equal to 1.5°), and avoids that the inner moving ring 21 and the outer static ring 11 are in edge contact and wear due to axis deflection.

[0034] Embodiments of the present application are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the application to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A thrust bearing structure for a drilling tool used in deep well petroleum drilling, comprising a stationary ring assembly (1), a dynamic ring assembly (2) and a ball assembly (3), characterized in that: The stationary ring assembly (1) includes an outer stationary ring (11), the inner ring of the outer stationary ring (11) is provided with a lower raceway (12), the dynamic ring assembly (2) includes an inner dynamic ring (21), the outer side wall of the inner dynamic ring (21) is provided with an upper raceway (22), the ball assembly (3) includes a large ball (31), a small ball (32), a large elastic retainer (33) and a small elastic retainer (34), the large ball (31) and the small ball (32) are both located at the lower raceway (12) and the upper raceway (22) between the stationary ring assembly (1) and the dynamic ring assembly (2), each large elastic retainer (33) is sleeved outside the large ball (31), each small elastic retainer (34) is sleeved outside the small ball (32), and an elastic beam (35) is connected between each large elastic retainer (33) and the small elastic retainer (34).

2. A deep well oil drilling tool thrust bearing structure as claimed in claim 1, characterized in that: At least two annular N-pole permanent magnets (13) and annular S-pole permanent magnets (14) are embedded on the outside of the outer static ring (11), and the annular N-pole permanent magnets (13) and the annular S-pole permanent magnets (14) are alternately distributed.

3. A deep well oil drilling tool thrust bearing structure as claimed in claim 1, characterized in that: A magnetic alloy sheet is installed in the inner moving ring (21), and the magnetic alloy sheet is installed in an axially corresponding position of the inner moving ring (21), and the magnetic alloy sheet is in an axially opposite area to the annular N-pole permanent magnet (13) and the annular S-pole permanent magnet (14) array.

4. A deep well oil drilling tool thrust bearing structure as claimed in claim 1, characterized in that: The volume of the small balls (32) is smaller than that of the large balls (31), and the large balls (31) and the small balls (32) are distributed alternately.

5. The deep well oil drilling tool thrust bearing structure according to claim 1, characterized in that: The upper raceway (22) extends from the inner moving ring (21) toward the central axis and has a smaller radius, corresponding to the small ball (32).

6. A deep well oil drilling tool thrust bearing structure as claimed in claim 1, characterized in that: The lower raceway (12) extends from the outer static ring (11) toward the central axis and has a larger radius, corresponding to the large ball (31).

7. A deep well oil drilling tool thrust bearing structure as claimed in claim 1, characterized in that: The large elastic retainer (33), the small elastic retainer (34) and the elastic beam (35) are formed into a wave shape as a whole, and a connecting frame (37) is fixedly installed between the large elastic retainer (33) and the small elastic retainer (34).

8. A deep well oil drilling tool thrust bearing structure as claimed in claim 7, characterized in that: The connecting frame (37) is located above the elastic beam (35), and a capsule (36) is embedded and fixedly installed above the elastic beam (35).

9. A deep well oil drilling tool thrust bearing structure as claimed in claim 8, characterized in that: The middle portion of the connecting frame (37) is an upward arc segment, and an elastic sheet (38) is fixedly installed below the arc segment. A cone thorn (39) is fixedly installed in the middle portion below the arc segment of the connecting frame (37).

10. The deep well oil drilling tool thrust bearing structure according to claim 1, characterized in that: At least two concave spherical surfaces (23) are provided inside the inner moving ring (21), a shaft (24) is provided inside the inner moving ring (21), and at least two convex spherical surfaces (25) are fixedly mounted on the surface of the shaft (24), and each convex spherical surface (25) can be correspondingly inserted into the concave spherical surface (23).

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