A seal for a roller cone drill bit

Abstract

The present application relates to a sealing device for roller cone drill bits, in particular to a sealing element for a roller cone drill bit. The sealing element comprises an inner-to-outer annularly distributed journal side bearing area, a compression energy storage area and a cone side bearing area. The sealing element is formed by a cross-sectional profile around a central axis. The profile lines at the two axial ends of the compression energy storage area comprise O n point, I n point and S n point. The profile line at the O n point protrudes outwardly from the compression energy storage area, forming a protrusion at the end of the sealing element. The profile line at the I n point is recessed inwardly from the compression energy storage area, forming a volume cavity at the end of the sealing element. The two axial ends of the compression energy storage area are formed with a radially diverging wavy profile. After being subjected to high pressure from the two sides, the sealing element can respond to the differential pressure condition underground, and provide additional restoring force for the sealing element through the pressure difference to enhance the sealing performance. The volume cavity can accommodate lubricating medium, effectively reducing the friction and wear of the sealing element during long-term use, and further prolonging the service life of the sealing element.

Description

Technical Field

[0001] This invention relates to sealing devices for roller cone drill bits, and more particularly to a seal for roller cone drill bits. Background Technology

[0002] Roller cone bits are commonly used rock-breaking tools in oil drilling engineering, and their service life directly affects drilling efficiency. Seals are the core components of the oil storage and lubrication sealing system. The lifespan of the roller cone is limited by the bearings, and the lifespan of the bearings depends on the seals. The quality of the seals affects, and even determines, the lifespan of the roller cone bit working downhole.

[0003] Common elastic seals such as O-rings and flat seals are widely used due to their simple structure and ease of assembly. However, under conditions of high pressure differential and high-speed relative motion downhole, conventional elastic seals typically face the following problems: they are sensitive to assembly eccentricity and tilting; during the assembly of roller cone bits, slight eccentricity, oscillation, or axial movement may occur, resulting in poor contact force during operation.

[0004] Traditional sealing sections are mostly circular or approximately rectangular. When they are radially pre-compressed, they are often accompanied by a large tight force. Under long-term load, this can lead to a relaxation effect and insufficient rebound compensation, which causes the contact pressure to decrease over time. The sealing contact zone weakens or even disappears, making it difficult to meet the requirements for long-term reliable sealing under high temperature, high pressure, high speed and strong vibration conditions. Summary of the Invention

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A seal for roller cone drill bits is provided, comprising:

[0007] The journal-side bearing area, compression energy storage area, and roller-side bearing area are distributed in a ring shape from the inside to the outside.

[0008] The seal is formed by a cross-sectional profile surrounding a central axis, and the profiles at both axial ends of the compressed energy storage region include O. n Point, I n Point and S n point;

[0009] O n Point, I n Point and S n Points are connected by contour lines, with O at the same end n Point and I n Point interval setting, S n The points are located at both ends of the contour line of the compressed energy storage area, serving as transition points connecting the journal-side bearing area and the roller-side bearing area.

[0010] O nThe outline at the point protrudes outward from the compressed energy storage area, forming a protrusion at the end of the seal;

[0011] I n The outline at the point is recessed into the compression storage area, forming a volume cavity at the end of the seal;

[0012] At both ends of the compressed energy storage region, O n Point and I n Point relative setting, S on the journal side n Point relative setting, S on the gear side n Point relative settings;

[0013] The bearing area on the journal side protrudes in an arc shape towards the inner side of the ring, and the bearing area on the roller side protrudes in an arc shape towards the outer side of the ring.

[0014] Furthermore, I n The distance between the point and the center line is D1, and 1 / 6D < D1 < 1 / 3D;

[0015] Where D is the width of the sealed cavity, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

[0016] Furthermore, O n The distance between the point and the center line is D2, where D1 < D2 < 1 / 2D;

[0017] Where D is the width of the sealed cavity, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

[0018] Furthermore, a complete cycle on the contour line of the compressed energy storage region includes one O. n Point and two I n A point, or an I n and two O n point;

[0019] The contour lines of the compressed energy storage regions at both ends of the axis include at least one complete cycle;

[0020] The S n Point O n Point and I n On the periodic extension line connecting the points.

[0021] Furthermore, the contour lines of the compressed energy storage regions at both ends of the axis include 1-3 complete cycles.

[0022] Furthermore, the bearing area on the roller side has a first transition slope with respect to the bearing area on the roller side, and the bearing area on the roller side has a transition point G1 on its cross-sectional profile.

[0023] Among them, the cross-sectional profile of the first transition hypotenuse is connected to S at both ends. n Points G1 and G1;

[0024] Furthermore, the first transition hypotenuse forms an angle θ with the center line, and the distance between point G1 and the center line is less than S. n The distance between the point and the centerline, where the centerline is perpendicular to the axis and passes through both ends of the axis. n The midpoint of the perpendicular distance from the point.

[0025] Furthermore, a second transition slope exists between the journal-side bearing area and the compression energy storage area, and a transition point G2 exists on the cross-sectional outline of the journal-side bearing area;

[0026] Among them, the cross-sectional profile of the second transition hypotenuse is connected to S at both ends. n Point G2 and point G2;

[0027] Furthermore, the second transition hypotenuse forms an angle θ with the center line, and the distance between point G2 on the second transition hypotenuse and the center line is less than S. n The distance between a point and the center line.

[0028] Furthermore, a circulation guide is provided at the axial end of the compressed energy storage area, and the circulation guide is provided on the protrusion;

[0029] The circulating flow guide section includes a first flow guide section and a second flow guide section arranged in an arc shape;

[0030] Wherein, the arc shape of the first guide section intersects the circular inclination of the protrusion, and the arc shape of the second guide section intersects the circular inclination of the protrusion;

[0031] Furthermore, the arc-shaped guiding directions of the first guide section and the second guide section are opposite;

[0032] The first guide section has a first inlet arc surface and a first outlet arc surface on both sides of its arc shape;

[0033] The second guide section has a second inlet arc surface and a second outlet arc surface on both sides of its arc shape.

[0034] Furthermore, the first guide portion and the second guide portion are grooves formed on the protrusion.

[0035] Furthermore, when the end of the compressed energy storage region has multiple sets of protrusions, the first guide section between adjacent protrusions is on the same arc-shaped path;

[0036] The second guide section between adjacent protrusions is on the same arc-shaped path.

[0037] The beneficial effects of the present invention are as follows: the surface of the compressed energy storage area is provided with protrusions and volume cavities, and a radially divergent wave-shaped profile is formed at both ends of the axial direction of the compressed energy storage area. After being subjected to the pressure of the high-pressure medium on both sides, it can respond to the downhole differential pressure conditions and provide additional restoring force to the seal through the pressure difference to enhance the sealing performance.

[0038] The volumetric cavity can hold lubricating media, effectively reducing friction and wear of the seals during long-term use, and further extending the service life of the seals.

[0039] The compressed energy storage area dynamically deforms and adapts its shape according to changes in liquid pressure during use, thereby providing continuous pressure compensation at the sealing contact surface and ensuring the stability of sealing performance under different operating conditions. Attached Figure Description

[0040] Figure 1 This is a structural diagram of the seal for roller cone drill bits according to the present invention;

[0041] Figure 2 This is a cross-sectional view of the seal for a roller cone drill bit according to the present invention;

[0042] Figure 3 This is a cross-sectional profile of the seal.

[0043] Figure 4 This is a schematic diagram of the seal installation.

[0044] Figure 5 A schematic diagram showing the arrangement of the circulation guide section at the end of the seal;

[0045] Figure 6 This is a schematic diagram of the flow of lubricating medium in the circulation guide section;

[0046] Figure 7 Structural diagrams of the first and second flow guide sections;

[0047] Figure 8 A schematic diagram showing the configuration of a circulation guide section with multiple protrusions;

[0048] Figure 9 This is a table showing the evaluation results of various dimensions of the sealing element according to the present invention.

[0049] Figure label:

[0050] Journal side bearing area 1, second transition inclined side 11, compression energy storage area 2, protrusion 21, volume cavity 22, first guide part 23, first inlet arc surface 231, first outlet arc surface 232, second guide part 24, second inlet arc surface 241, second outlet arc surface 242, roller wheel side bearing area 3, first transition inclined side 31;

[0051] 4. Central axis, 5. Journal, 6. Gear, 61. Sealing cavity. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments thereof.

[0053] Example 1:

[0054] Reference Figures 1-8 The present invention provides a seal for a roller cone drill bit, comprising:

[0055] The journal side bearing area 1, the compression energy storage area 2, and the roller side bearing area 3 are distributed in a ring shape from the inside to the outside.

[0056] The seal is formed by a cross-sectional profile surrounding the central axis 4, and the profiles at both ends of the axial direction of the compression storage region 2 include O. n Point, I n Point and S n point;

[0057] O n Point, I n Point and S n Points are connected by contour lines, with O at the same end n Point and I n Point interval setting, S n The points are located at both ends of the contour line of the compression energy storage area 2, serving as transition points connecting the journal-side bearing area 1 and the roller-side bearing area 3;

[0058] O n The outline at the point protrudes outward from the compression storage area 2, forming a protrusion 21 at the end of the seal;

[0059] I n The outline at the point is recessed into the compression storage area 2, forming a volume cavity 22 at the end of the seal;

[0060] At both ends of the axial direction of the compressed energy storage region 2, O n Point and I n Point relative setting, S on journal 5 side n Point relative setting, S on the 6th side of the gear n Point relative settings;

[0061] The journal-side bearing area 1 protrudes in an arc shape towards the inner side of the ring, while the roller-side bearing area 3 protrudes in an arc shape towards the outer side of the ring.

[0062] When the seal is assembled into the sealing cavity 61, the interference fit generates a radial compression δ, which is mainly borne by the compression energy storage region 2, located at its outer apex O. n Inner vertex I n Transition point S nThe contour formed creates a controllable radial deformation space, thereby achieving radial compression and energy storage rebound.

[0063] O n A ring-shaped protrusion 21 is formed on the axial end of the seal at a point away from the center of the compression storage zone 2. n The point near the center of the compression storage zone 2 forms an annular volume cavity 22 at the axial end of the seal. And the O at both axial ends... n (n=a, b, c…) points and I n (n=a, b, c…) Points are set relative to each other, that is, the O points at both ends of the axis are corresponding to each other. a Point and I a The point is equidistant from the axis line, O b Point and I b The distance between the point and the axis is the same, so that the undulation inflection points of the two contour lines of the compressed energy storage region 2 at both ends of the axis are the same, and the cross-sectional contour of the compressed energy storage region 2 presents a periodic undulating wave shape in the radial direction.

[0064] S on journal 5 side n (n=a, b) points are set relative to each other, S on the 6th side of the gear. n (n=c, d) points are set relative to each other to make the thickness of the compressed energy storage zone 2 uniform at both ends;

[0065] In this invention, the axial direction refers to the direction of the central axis of the seal, and the radial direction refers to the circumferential radial direction of the seal.

[0066] In this invention, the pressure difference between the lubricating medium and the drilling fluid on both sides allows the seal to recover its deformation, thereby providing contact pressure. When traditional O-rings or rectangular rings are compressed within the groove, the material deforms primarily through overall volume compression, forming strong constraints on the groove walls. Rubber is nearly incompressible, and deformation requires lateral bulging. When the bulging space is insufficient or strongly constrained, the assembly reaction force increases sharply, resulting in higher equivalent stiffness.

[0067] Compared with traditional seals that can only provide contact pressure through interference compression during assembly, the present invention sets the seal cross-section as an annular volume cavity 22. In the initial stage of assembly compression, the main deformation of the seal is not the overall material being forcibly flattened to form lateral expansion, but rather the volume change of the cavity preferentially converging, thereby providing a deformable space for the liquid on both sides to enter.

[0068] Because the volumetric cavity 22 provides effective volume adjustment margin, during normal operation, the medium on both sides of the seal is forced into the volumetric cavity 22 by pressure. At this time, the seal begins to deform and has a tendency to recover from its pre-compression state, which reduces the rate of increase of internal force required per unit compression, effectively reducing the equivalent stiffness of the seal. Under the same assembly compression conditions, a smaller assembly preload can be used compared to traditional sealing structures.

[0069] Moreover, during downhole operation, driven by the pressure difference between the lubricating medium and the drilling fluid, the compressed energy storage region 2 generates an additional radial force component through elastic recovery, thereby providing an additional radial compensation force based on the original preload. This enables the sealing contact band to maintain stable fitting under dynamic conditions, thereby compensating for insufficient contact pressure that may be caused by low preload, and ensuring stable and reliable performance of the sealing member.

[0070] The radial compression amount is mainly borne by the energy storage region 2, which avoids early stress concentration in the bearing region, thereby allowing a larger compression ratio without significantly increasing the peak contact pressure. During operation, the temperature rise of the sealing member is mainly generated by frictional heat. By taking the heat generation amount as a parameter, the following key parameters can be obtained: average contact pressure , effective contact area , relative sliding speed v, friction coefficient . The frictional heat generation formula can be approximated as:

[0071]

[0072] Therefore, to reduce heat generation, the option of reducing the average contact pressure or reducing the effective contact area can be selected. Since reducing the effective contact area is not conducive to actual working conditions, reducing the average contact pressure is selected within a controllable range, that is, reducing the normal contact pressure N. In this embodiment, a wavy energy storage region is used to provide main deformation, and the equivalent radial stiffness thereof is , and the radial compression amount generated during assembly is , the normal contact pressure N can be obtained according to generalized Hooke's law:

[0073]

[0074] Compared with the equivalent stiffness of a traditional sealing member , the wavy structure has lower equivalent stiffness due to the existence of the cavity and curved transition , ⇒N<N0. It is not rigorous enough to only reduce N. The wavy energy storage region acts as a buffer layer, enabling the contact bands on the side of the journal 5 and the side of the cone 6 to approach balanced load bearing, thereby reducing the local peak caused by the single contact band bearing all the load.

[0075] A load distribution coefficient is used to describe: N=N1+N2, N1= N, N2= N, where N is the contact normal pressure of the seal, N1 is the normal pressure of the bearing area 3 on the roller side, and N2 is the normal pressure of the bearing area 1 on the journal side; in the case of eccentricity and oscillation of the traditional structure It is not easy to approach 0.5, while the wave-shaped structure, due to its good self-adaptability, makes it... A value closer to 0.5 translates to a compensatory ability after wear, ensuring a good sealing condition for the seal. Furthermore, under differential pressure, it allows the journal-side bearing area 1 and the roller-side bearing area 3 to better fit against the side of the sealing groove, thereby reducing the pressure on the sealing groove while increasing the pressure, reducing the heat generated by rotation, and further reducing the wear at the contact point between the seal and the sealing groove, effectively improving the life of the seal.

[0076] When a seal operates for an extended period, it generates a significant amount of heat; the temperature rise can be expressed as... Where h is the equivalent heat transfer coefficient, It is the equivalent area that participates in heat dissipation. The heat is generated by friction. Compared to traditional seals, the corrugated energy storage area is recessed inward to form a chamber, which can hold more lubricating medium. Furthermore, the corrugated structure has a larger surface area, thus increasing the effective area for heat dissipation. < .

[0077] The journal-side bearing area 1 is used to abut against the journal and seal both sides of the journal. The middle of the journal-side bearing area 1 protrudes inward in an arc shape, that is, it protrudes towards the journal side, and its cross-sectional profile is an arc curve. This ensures that after installation, the central protruding area of ​​the journal-side bearing area 1 has the tightest contact with the journal side. When the compression energy storage area 2 is compressed on both sides, it is gradually squeezed outward from the central protrusion, making it less likely for gaps to exist between the contact surfaces, and the contact deformation is more uniform, which facilitates the distribution of the compression force throughout the interior of the seal. When the seal slides on the journal surface, the arc-shaped protrusion also facilitates its sliding and reduces the sliding friction.

[0078] The bearing area 3 on the roller cone side is used to abut against the bottom of the sealing cavity 61 on the roller cone side and to seal both sides of the sealing groove. The middle of the bearing area 3 on the roller cone side protrudes outward in an arc shape, that is, it protrudes towards the bottom of the sealing cavity 61, and its cross-sectional profile is an arc curve, so that the middle protruding area of ​​the bearing area 3 on the roller cone side has the tightest abutment against the bottom of the sealing cavity 61 after installation. When the two sides of the compression energy storage area 2 are compressed, it gradually squeezes and contacts the journal side from the middle protrusion outward. There are not many gaps between the contact surfaces, and the contact deformation is more uniform, which makes it easier to distribute the compression force to the outside of the entire seal.

[0079] In some embodiments, the cross-sectional profiles of the journal-side bearing area 1 and the roller-side bearing area 3 can also be in the form of "straight line-curve-straight line", as long as the protruding point in the middle is an arc.

[0080] As a preferred option, O n Point and I n The points are connected by curves. Compared with straight lines, the wave-shaped structure formed by the curve connection has less stress concentration, which can effectively increase the service life of the compressed energy storage area 2.

[0081] Example 2:

[0082] Reference Figure 3 , Figure 4 Furthermore, I n The distance between the point and the center line is D1, and 1 / 6D < D1 < 1 / 3D;

[0083] Where D is the width of the sealing cavity 61, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

[0084] O n The distance between the point and the center line is D2, where D1 < D2 < 1 / 2D;

[0085] Where D is the width of the sealing cavity 61, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

[0086] I n The offset distance D1 from the point to the center line determines the depth of the concave cavity and the compressible stroke. n The offset distance D2 from the point to the centerline determines the level of the outward convex positioning support and the radial restoring force output. The difference between D1 and D2, ΔD = D2 - D1, determines the matching relationship between the equivalent radial stiffness and the adaptability.

[0087] By I n The deviation distance between the point and the center line is limited to D1 greater than 1 / 6D < D1 < 1 / 3D, O n The offset distance between the point and the centerline is limited to D1 < D2 < 1 / 2D, so that the seal has sufficient compressible stroke to accommodate eccentricity, oscillation and dynamic clearance changes while providing the necessary radial preload.

[0088] Figure 9 This is a table showing the evaluation results of various dimensions of the seal in this invention. In this embodiment, by increasing ΔD, O... n –I n –S nThe contour formed creates a more controllable radial deformation space, making it easier for the compressed energy storage area 2 to undergo controllable elastic deformation during assembly and under pressure. This results in a reduction in equivalent radial stiffness, a more compliant structure, and easier radial compression.

[0089] In downhole operation, the pressure difference between the lubricating medium and the drilling fluid acts on the effective pressure-bearing area of ​​the compression storage zone 2, forming an additional radial compensation effect, thereby dynamically compensating for the contact load gap caused by the reduction in assembly preload. Therefore, even with a smaller assembly preload, the contact pressure at the sealing interface in this embodiment can remain unchanged, or even increase further under pressure difference excitation, demonstrating the pressure compensation advantage and improved adaptability brought about by the increase in structural parameter ΔD.

[0090] When 1 / 6D < D1 < 1 / 3D and D1 < D2 < 1 / 2D, the sealing performance of the seal can be guaranteed, the life of the seal can be improved, and the wear and heat generation of the seal can be kept within the acceptable range.

[0091] Example 3:

[0092] Reference Figure 3 Furthermore, a complete cycle on the contour line of the compressed energy storage region 2 includes one O. n Point and two I n A point, or an I n and two O n point;

[0093] The contour lines of the compression storage region 2 at both ends of the axis include at least one complete cycle.

[0094] The wavelength of a complete cycle is L1, and the contour lines at both ends of the compressed energy storage region 2 contain at least one complete cycle, which includes O. n The protrusions 21 and I corresponding to the point n The recess corresponding to the point, that is, within a complete cycle, includes at least one volumetric cavity 22 (with two I on one side) capable of retaining lubricating medium. n At point 22, there are two volumetric cavities 22, with one I on one side. n At the same time, there is a volumetric cavity 22, which promotes the formation of a lubricating film and improves heat dissipation conditions, thereby reducing the frictional heat generation and temperature rise of the seal.

[0095] S n Point O n Point and I n On the periodic extension line connecting the points, maintain the periodic contour line of the compressed energy storage section to avoid changing the shape of the contour line and causing localized stress concentration.

[0096] Example 4:

[0097] Reference Figure 3 Furthermore, the contour lines of the compression storage region 2 at both ends of the axis include 1-3 complete cycles.

[0098] Under the condition that the circumferential length of the seal is the same, the increase in the number of complete cycles makes the protrusions 21 and the volume cavity 22 more densely distributed, thereby increasing the effective area of ​​the contact surface between the seal and the lubricating medium.

[0099] At least one volumetric cavity 22 is conducive to the retention and replenishment of lubricating medium, promotes the formation of lubricating film and improves heat dissipation conditions, thereby reducing frictional heat generation and temperature rise of the seal.

[0100] However, when the number of complete cycles is too high, the uneven transition areas (edges, abrupt changes in curvature) become stress concentration points, increasing the number of such weak areas, easily leading to localized stress concentration and reducing the fatigue life of the structure. Under long-term vibration and alternating compressive loads, it is more prone to tearing or fracture. Therefore, the number of complete cycles is preferably 1 to 3 to achieve a balance between lubrication and heat dissipation capacity and structural reliability.

[0101] Example 5:

[0102] Reference Figure 2 , Figure 3 Furthermore, the bearing area 3 on the roller side has a first transition inclined side 31 between it and the roller side bearing area 3, and there is a transition point G1 on the cross-sectional outline of the bearing area 3 on the roller side.

[0103] Among them, the cross-sectional outline of the first transition hypotenuse 31 is connected to S at both ends. n Points G1 and G1, the first transition inclined edge 31 has two, which are set at both ends of the axial direction of the bearing area 3 on the roller side, and are respectively connected to the ends of the compression energy storage area 2 at both ends of the axial direction.

[0104] Furthermore, the first transition hypotenuse 31 forms an angle θ with the center line, and the distance between point G1 and the center line is less than S. n The distance between the point and the centerline, where the centerline is perpendicular to the axis and passes through both ends of the axis. n The midpoint of the vertical distance between the points. The first transition inclined edge 31 is tilted from the bearing area 3 on the toothed side to the compression energy storage area 2, so that the first transition inclined edge 31 can fit against the bottom of the sealing cavity 61 after being radially compressed.

[0105] When a radial force is applied to the seal, the first transition bevels 31 on both sides of the roller cone bearing area undergo elastic deformation. The restoring force generated by this elastic deformation causes the two first transition bevels 31 to firmly abut against the bottom of the sealing cavity 61 on the roller cone bit, enhancing the sealing performance between the first transition bevels 31 and the inner side of the sealing cavity 61. This enables the roller cone bearing area 3 to withstand greater downhole pressure, improving the working performance and safety performance of the seal.

[0106] Preferably, θ=30° allows the first transition slope 31 to receive the pressure transmitted from one side of the compressed energy storage area 2, while maintaining the fit with the bottom of the sealing cavity 61.

[0107] Example 6:

[0108] Reference Figure 2 , Figure 3 Furthermore, there is a second transition hypotenuse 11 between the journal-side bearing area 1 and the compression energy storage area, and there is a transition point G2 on the cross-sectional outline of the journal-side bearing area 1;

[0109] Among them, the cross-sectional outline of the second transition hypotenuse 11 is connected to S at both ends. n Points G1 and G2, the second transition inclined edge 11 has two sides, which are set at both ends of the bearing area 1 on the journal side, and are respectively connected to the ends of the compression energy storage area 2 at both ends of the axial direction.

[0110] Furthermore, the second transition hypotenuse 11 forms an angle θ with the center line, and the distance between point G2 on the second transition hypotenuse 11 and the center line is less than S. n The distance between the point and the center line. The second transition inclined edge 11 is tilted from the bearing area 1 on the journal side to the compression energy storage area 2, so that the second transition inclined edge 11 can fit against the bottom of the sealing cavity 61 after being radially compressed.

[0111] When a radial force is applied to the seal, the second transition bevels 11 on both sides of the journal bearing area undergo elastic deformation. The restoring force generated by this elastic deformation causes the two second transition bevels 11 to firmly abut against the journal surface, enhancing the sealing performance between the second transition bevels 11 and the journal. This enables the journal-side bearing area 1 to withstand greater downhole pressure, improving the working performance and safety performance of the seal.

[0112] Preferably, θ=30° allows the second transition slope 11 to both receive the pressure transmitted from one side of the compression energy storage region 2 and maintain the contact strength with the journal surface.

[0113] Example 7:

[0114] Reference Figures 5-7 Furthermore, a circulation guide is provided at the axial end of the compressed energy storage area 2, and the circulation guide is provided on the protrusion 21;

[0115] The circulation guide section includes a first guide section 23 and a second guide section 24 arranged in an arc shape;

[0116] Among them, the arc shape of the first guide portion 23 intersects the circular shape of the protrusion 21 at an incline, and the arc shape of the second guide portion 24 intersects the circular shape of the protrusion 21 at an incline.

[0117] Furthermore, the arc-shaped guiding directions of the first guide section 23 and the second guide section 24 are opposite;

[0118] The first guide section has a first inlet arc surface 231 and a first outlet arc surface 232 on both sides of its arc shape;

[0119] The second guide section 24 has a second inlet arc surface 241 and a second outlet arc surface 242 on both sides of its arc shape.

[0120] The protrusion 21 is located at the annular high point on the axial end face of the compression energy storage region 2, and is adjacent to I. n The adjacent recesses corresponding to the points can retain the lubricating medium in the volume cavity 22 formed by the recesses, which can play a role in lubrication and cooling. However, after the gear is used continuously for a long time, the temperature of the seal and its surroundings will rise. The presence of the protrusion 21 hinders the radial flow of the lubricating medium in the seal, resulting in the lubricating medium remaining around the seal being high-temperature.

[0121] In this embodiment, a first guide portion 23 and a second guide portion 24 are provided on the protrusion 21, with an inlet arc surface and an outlet arc surface on the inner and outer sides, respectively. The lubricating medium located on the inner side of the end face is guided to the outer side of the end face, and at the same time, the lubricating medium located on the outer side of the end face is guided to the inner side of the end face, which promotes the flow of the lubricating medium on the end face, carries away the high-temperature lubricating medium, and makes the overall temperature of the seal tend to be uniform.

[0122] Specifically, the first guide portion 23 and the second guide portion 24 are configured as arc-shaped grooves or protrusions. The inner and outer arc sides of the grooves or protrusions have arc-shaped surfaces. When the lubricating medium flows in an annular manner along the surface of the protrusion 21, it will hit the surface facing it. At this time, if the radially outer end of the arc-shaped surface is within the 90° component of the lubricating medium flow direction, a portion of the lubricating medium will flow into the outer volume cavity 22 along the arc-shaped surface.

[0123] like Figure 6 As shown, the lubricating medium flows clockwise, and a portion of the lubricating medium inside the protrusion 21 enters the groove of the first guide portion 23 and hits the first introductory arc surface 231. The angle β between the radially outward end of the first introductory arc surface 231 and the annular flow direction of the lubricating medium is less than 90°. At this time, a portion of the lubricating medium enters the volume cavity 22 along the first introductory arc surface 231.

[0124] When the lubricating medium inside the protrusion 21 flows through the second guide section 24, since the arc directions of the first guide section 23 and the second guide section 24 are opposite, the lubricating medium is met by the second lead-out arc surface 242. The end of the second lead-out arc surface 242 facing the radially outward side makes an angle greater than 90° with the annular flow direction of the lubricating medium, so the lubricating medium cannot enter the volume cavity 22.

[0125] The lubricating medium squeezed into the volume cavity 22 is pushed to flow clockwise in the volume cavity 22 along the squeezing direction. When it flows through the second lead-out arc surface 242, the angle between the end of the second lead-out arc surface 242 facing the radially inward side and the annular flow direction of the lubricating medium is less than 90°. At this time, part of the lubricating medium enters the volume cavity 22 along the second lead-out arc surface 242, realizing the circulation of the lubricating medium on both sides of the protrusion 21.

[0126] When the lubricating medium flows counterclockwise, the flow direction is reversed. In the first guide section 23, the first outgoing arc surface 232 faces the lubricating medium, while the radially outward end of the second outgoing arc surface 242 forms an angle greater than 90° with the annular flow direction of the lubricating medium, preventing the lubricating medium from entering the volume cavity 22. In the second guide section 24, the radially outward end of the second introductory arc surface 241 forms an angle β less than 90° with the annular flow direction of the lubricating medium, allowing some of the lubricating medium to enter the volume cavity 22 along the second introductory arc surface 241.

[0127] The lubricating medium squeezed into the volume cavity 22 is pushed to flow counterclockwise in the volume cavity 22 along the squeezing direction. When it flows through the first lead-out arc surface 232, the angle between the end of the first lead-out arc surface 232 facing the radially inward side and the annular flow direction of the lubricating medium is less than 90°. At this time, part of the lubricating medium enters the volume cavity 22 along the second lead-out arc surface 242, realizing the circulation of the lubricating medium on both sides of the protrusion 21.

[0128] The first guide section 23 and the second guide section 24 have opposite arc directions, making their functions complementary. When the lubricating medium rotates clockwise, it flows into the volume chamber 22 from the first inlet arc surface 231 on the first guide section 23 and then flows out of the volume chamber 22 from the second outlet arc surface 242 on the second guide section 24. When the flow direction of the lubricating medium changes to counterclockwise, it enters again from the second inlet arc surface 241 and flows out from the first outlet arc surface 232. Thus, regardless of the rotation direction of the gear, the lubricating medium around the sealing ring can be driven to flow.

[0129] Example 8:

[0130] Reference Figure 7 Furthermore, the first guide portion 23 and the second guide portion 24 are grooves formed on the protrusion 21.

[0131] By configuring the first guide portion 23 and the second guide portion 24 as grooves, when the thickness of both ends of the seal is equal to the width D of the sealing cavity 61, or when one end of the seal is in close contact with the side wall of the sealing cavity 61, the grooves can provide a channel for the lubricating medium to flow, so that the lubricating medium can flow in it.

[0132] Example 9:

[0133] Reference Figure 8 Furthermore, when the end of the compressed energy storage region 2 has multiple sets of protrusions 21, the first guide section 23 between adjacent protrusions 21 is on the same arc-shaped path;

[0134] The second guide section 24 between adjacent protrusions 21 is on the same arc-shaped path.

[0135] Although there are volume cavities 22 between adjacent protrusions 21, making the first guide section 23 discontinuous, the two adjacent first guide sections 23 are on the same arc-shaped path, which allows a portion of the lubricating medium entering the previous volume cavity 22 to move along the path and enter the next volume cavity 22, thereby increasing the force of the lubricating medium entering the next volume cavity 22 and pushing the lubricating medium to squeeze in and flow.

[0136] When drawing out the lubricating medium, the hot lubricating medium on the outside can also be quickly discharged from the guide section, preventing it from staying in the middle volume cavity 22.

[0137] In the description of the embodiments of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "center," "top," "bottom," "top," "bottom," "inner," "outer," "inner side," and "outer side," 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 the present invention 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 the present invention. "Inner side" refers to the interior or enclosed area or space. "Outer perimeter" refers to the area surrounding a specific component or specific area.

[0138] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0139] In the description of embodiments of the present invention, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0140] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A seal for roller cone drill bits, characterized in that, include: The journal-side bearing area, compression energy storage area, and roller-side bearing area are distributed in a ring shape from the inside to the outside. The seal is formed by a cross-sectional profile surrounding a central axis, and the profiles at both axial ends of the compressed energy storage region include O. n Point, I n Point and S n point; O n Point, I n Point and S n Points are connected by contour lines, with O at the same end n Point and I n Point interval setting, S n The points are located at both ends of the contour line of the compressed energy storage area, serving as transition points connecting the journal-side bearing area and the roller-side bearing area. O n The outline at the point protrudes outward from the compressed energy storage area, forming a protrusion at the end of the seal; I n The outline at the point is recessed into the compression storage area, forming a volume cavity at the end of the seal; At both ends of the compressed energy storage region, O n Point and I n Point relative setting, S on the journal side n Point relative setting, S on the gear side n Point relative settings; The bearing area on the journal side protrudes in an arc shape towards the inner side of the ring, and the bearing area on the roller side protrudes in an arc shape towards the outer side of the ring; A circulation guide is provided at the axial end of the compressed energy storage area, and the circulation guide is provided on the protrusion; The circulating flow guide section includes a first flow guide section and a second flow guide section arranged in an arc shape; Wherein, the arc shape of the first guide section intersects the circular inclination of the protrusion, and the arc shape of the second guide section intersects the circular inclination of the protrusion; Furthermore, the arc-shaped guiding directions of the first guide section and the second guide section are opposite; The first guide section has a first inlet arc surface and a first outlet arc surface on both sides of its arc shape; The second guide section has a second inlet arc surface and a second outlet arc surface on both sides of its arc shape.

2. The seal for roller cone drill bits according to claim 1, characterized in that: I n The distance between the point and the center line is D1, and 1 / 6D < D1 < 1 / 3D; Where D is the width of the sealed cavity, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

3. The seal for roller cone drill bits according to claim 2, characterized in that: O n The distance between the point and the center line is D2, where D1 < D2 < 1 / 2D; Where D is the width of the sealed cavity, and the centerline is perpendicular to the axis and passes through both ends I in the axial direction. n The midpoint of the perpendicular distance from the point.

4. The seal for roller cone drill bits according to claim 1, characterized in that: A complete cycle on the contour line of a compressed energy storage region includes one O n Point and two I n A point, or an I n and two O n point; The contour lines of the compressed energy storage regions at both ends of the axis include at least one complete cycle; The S n Point O n Point and I n On the periodic extension line connecting the points.

5. The seal for roller cone drill bits according to claim 4, characterized in that: The contour lines of the compressed energy storage regions at both ends of the axis include 1-3 complete cycles.

6. The seal for roller cone drill bits according to claim 1, characterized in that: There is a first transition slope between the roller cone side bearing area and the compression energy storage area, and there is a transition point G1 on the cross-sectional outline of the roller cone side bearing area. Among them, the cross-sectional profile of the first transition hypotenuse is connected to S at both ends. n Points G1 and G1; Furthermore, the first transition hypotenuse forms an angle θ with the center line, and the distance between point G1 and the center line is less than S. n The distance between the point and the centerline, where the centerline is perpendicular to the axis and passes through both ends of the axis. n The midpoint of the perpendicular distance from the point.

7. The seal for roller cone drill bits according to claim 1 or 6, characterized in that: There is a second transition slope between the journal-side bearing area and the compression energy storage area, and there is a transition point G2 on the cross-sectional outline of the journal-side bearing area. Among them, the cross-sectional profile of the second transition hypotenuse is connected to S at both ends. n Point G2 and point G2; Furthermore, the second transition hypotenuse forms an angle θ with the center line, and the distance between point G2 on the second transition hypotenuse and the center line is less than S. n The distance between a point and the center line.

8. The seal for roller cone drill bits according to claim 1, characterized in that: The first and second guide portions are grooves, which are formed on the protrusions.

9. The seal for roller cone drill bits according to claim 1 or 8, characterized in that: When the end of the compressed energy storage region has multiple sets of protrusions, the first guide section between adjacent protrusions is on the same arc-shaped path; The second guide section between adjacent protrusions is on the same arc-shaped path.

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