CN221074102U - Pull rod locking bearing - Google Patents

Abstract

The application relates to the technical field of drilling tools, in particular to a pull rod locking bearing. The pull rod locking bearing comprises a roller, a bit leg and a pull rod. The inner part of the cone is penetrated with a cone inner hole, the cone inner hole comprises a first cone inner hole and a second cone inner hole, and a locking section is arranged between the first cone inner hole and the second cone inner hole; the bit leg comprises a shaft neck section and a limiting section, the shaft neck section is arranged in the second cone inner hole, the bit leg inner hole penetrates through the bit leg, and the bit leg inner hole and the cone inner hole are coaxially arranged; the pull rod penetrates through the bit leg inner hole and the cone inner hole, the pull rod is connected with the bit leg through the adjusting fixing piece, and the locking section is limited between the pull rod and the bit leg. The embodiment of the application provides a pull rod locking bearing to solve the problems that in the related art, the abrasion of a steel ball and a steel ball runway is caused by high axial running quantity in a steel ball locking structure and large swing quantity of a cone, and the abrasion of the steel ball and the steel ball runway is further aggravated.

Description

Pull rod locking bearing

Technical Field

The application relates to the technical field of drilling tools, in particular to a pull rod locking bearing.

Background

In the prior art, three types of locking structures of cone bit leg bearings are available: the steel ball locking structure has the advantages that the steel ball locking structure is low in load, low in contact stress of the steel ball and a steel ball runway, slight in fatigue pitting corrosion, low in abrasion speed and small in abrasion loss when drilling a low-bit-pressure vertical well, so that the reliability is high; and because of its simple structure, so it is most widely used.

But currently, the drilling mode is gradually changed into the high-bit pressure directional well drilling mode. In a high-bit-pressure directional well drilling mode, a cone bit leg of a steel ball locking structure is adopted, the steel ball is subjected to large load, the contact stress of the steel ball and a steel ball runway is high, fatigue pitting corrosion is serious, the abrasion speed is high, and the abrasion loss is large; after the steel ball and the steel ball runway are worn, the axial running amount and the swinging amount of the cone relative to the bit leg are increased, the abrasion of the steel ball and the steel ball runway is further increased, and vicious circle is formed, so that the reliability of the steel ball locking structure is low, the bearing life is short, and the service life of the drill bit is short.

Disclosure of utility model

The embodiment of the application provides a pull rod locking bearing, which aims to solve the problems that in the related art, the abrasion of a steel ball and a steel ball runway is caused by high axial running quantity in a steel ball locking structure and large swing quantity of a cone, and the abrasion of the steel ball and the steel ball runway is further aggravated.

To achieve the above object, an embodiment of the present application provides a pull rod locking bearing, including:

The inner part of the cone is penetrated with a cone inner hole, the cone inner hole comprises a first cone inner hole and a second cone inner hole, and a locking section is arranged between the first cone inner hole and the second cone inner hole;

the bit leg comprises a shaft neck section and a limiting section, wherein the shaft neck section is arranged in the second cone inner hole, the bit leg inner hole penetrates through the bit leg, and the bit leg inner hole and the cone inner hole are coaxially arranged;

The pull rod penetrates through the bit leg inner hole and the cone inner hole, the pull rod is connected with the bit leg through the adjusting fixing piece, and the locking section is limited between the pull rod and the bit leg.

In some embodiments, the spacing section of the bit leg is greater in radial dimension than the diameter of a journal section located in the second cone bore, the spacing section being defined in an end face of the cone;

The end of the shaft neck section, which is far away from the limiting section, is provided with a bit leg thrust surface, and the bit leg thrust surface is abutted against one end of the locking section, which faces the inner hole of the second cone.

In some embodiments, the pull rod comprises a pull rod body and a pull rod locking block, wherein the diameter of the pull rod locking block is larger than that of the pull rod body, the pull rod body is arranged in the bit leg inner hole in a penetrating mode, and the pull rod locking block is abutted to one end, facing the first cone inner hole, of the locking section.

In some embodiments, the diameter of the pull rod locking block is x, the inner diameter of the second cone inner hole is D1, the diameter of the locking section is D2, the inner diameter of the first cone inner hole is D3, and the relationship among the diameters x, D1, D2, and D3 is: d1> D3> x > D2.

In some embodiments, the distance C between the pull rod locking block and the bit leg is greater than the thickness h of the locking section, and the difference between C and h ranges from 0.1 mm to 0.6mm.

In some embodiments, the bit leg bores include a first bit leg bore and a second bit leg bore, the second bit leg bore having a diameter greater than the diameter of the first bit leg bore;

The pull rod comprises a pull rod locking block, a pull rod body and a thread section, wherein the pull rod locking block is abutted against one end of the locking section, which faces the first cone inner hole, the pull rod body is arranged in the bit leg inner hole in a penetrating manner, and the thread section is positioned at one end of the pull rod body, which is far away from the pull rod locking block;

The adjusting and fixing piece comprises a lock nut which is in threaded connection with the threaded section, and the outer diameter of the lock nut is larger than the diameter of the inner hole of the first bit leg.

In some embodiments, the surface of the pull rod locking block, which is abutted against the locking section, is a conical surface.

In some embodiments, a movable sealing groove is formed in the inner hole of the second cone, and a movable sealing ring is arranged in the movable sealing groove.

In some embodiments, a shoulder is disposed in the first cone bore, the shoulder having a sealing mandrel mounted thereon;

Along the circumference of sealing the dabber, set up quiet seal groove in the first cone hole, be equipped with quiet sealing washer in the quiet seal groove, quiet sealing washer with sealing the dabber circumference looks butt.

In some embodiments, a clamp spring groove is formed in the inner hole of the first cone, and the clamp spring groove is positioned at one side of the static seal groove away from the locking section;

And a clamp spring is arranged in the clamp spring groove and is abutted to one end, far away from the locking section, of the sealing mandrel.

The technical scheme provided by the application has the beneficial effects that:

The embodiment of the application provides a pull rod locking bearing, which is characterized in that a cone inner hole comprises two sections, namely a first cone inner hole and a second cone inner hole, a locking section is arranged between the first cone inner hole and the second cone inner hole, the locking section can be limited between a bit leg penetrating through a cone and a pull rod, namely the bit leg and the pull rod are clamped by the locking section, so that the relative fixation of the bit leg, the pull rod and the cone is realized;

The pull rod is connected with the bit leg through an adjusting fixing piece, and the adjusting fixing piece is used for adjusting. The axial running amount of the cone relative to the bit leg can be adjusted, after the axial running amount is adjusted to a certain value, the running amount of the cone relative to the bit leg shaft neck is reduced when the cone rotates, the bearing stress state is improved, and the bearing service life is prolonged, so that the problems that the axial running amount in a steel ball locking structure is large, the running amount of the cone is large, and the abrasion of the steel ball and a steel ball runway is further aggravated due to the abrasion of the steel ball and the steel ball runway under high bit pressure in the related technology can be solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a cross-sectional view of a first embodiment of a pull rod locking bearing provided in accordance with an embodiment of the present application;

FIG. 2 is a cross-sectional view of a roller cone in a first embodiment of a pull rod locking bearing provided in accordance with an embodiment of the present application;

FIG. 3 is an enlarged view of FIG. 2 at A;

FIG. 4 is a cross-sectional view of a bit leg in a first embodiment of a pull rod lock bearing according to an embodiment of the present application;

FIG. 5 is a cross-sectional view of a pull rod in a first pull rod locking bearing embodiment of the present application;

FIG. 6 is a cross-sectional view of an adjustment fixture in a first embodiment of a pull rod locking bearing according to an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating the cooperation of a bit leg and a pull rod in a first embodiment of a pull rod locking bearing according to an embodiment of the present application;

FIG. 8 is a cross-sectional view of a sealing mandrel in a first embodiment of a pull rod lock bearing provided in accordance with an embodiment of the present application;

FIG. 9 is a cross-sectional view of a second embodiment of a pull rod locking bearing provided in accordance with an embodiment of the present application;

fig. 10 is a cross-sectional view of a third embodiment of a pull rod locking bearing provided in accordance with an embodiment of the present application.

In the figure: 1. a roller cone; 11. a cone inner hole; 111. a first cone inner bore; 112. a second cone inner bore; 12. a locking section; 121. a cone locking surface; 122. a cone thrust surface; 13. a dynamic seal groove; 131. a movable sealing ring; 14. cutting teeth; 15. a clamp spring groove; 151. clamping springs; 16. static seal groove; 161. a static sealing ring; 17. a shoulder; 2. leg portions; 21. an inner bore of the bit leg; 211. a first leg hole; 212. a second leg hole; 22. a journal section; 221. a bit leg thrust surface; 23. a limiting section; 24. oil holes; 25. a long oil hole; 3. a pull rod; 31. a pull rod locking block; 311. a pull rod locking surface; 32. a pull rod body; 33. a threaded section; 4. adjusting the fixing piece; 41. a lock nut; 42. a lock nut seal; 5. sealing the mandrel; 51. alloy teeth; 6. an annular gasket; 7. thrust washers.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The embodiment of the application provides a pull rod locking bearing, which can solve the problems of large axial running amount and large cone swing amount in a steel ball locking structure and further aggravate the abrasion of a steel ball and a steel ball runway caused by the abrasion of the steel ball and the steel ball runway under high bit pressure in the related art.

Referring to fig. 1 to 10, the present application provides a pull rod locking bearing comprising a cone 1, a bit leg 2, a pull rod 3 and an adjustment fixture 4. Specifically, the cone 1 has a cone inner bore 11 penetrating therethrough, and as shown in fig. 2, the cone inner bore 11 includes a first cone inner bore 111 and a second cone inner bore 112, and a locking section 12 is disposed between the first cone inner bore 111 and the second cone inner bore 112.

Further, bit leg 2 includes a journal segment 22 and a limiting segment 23, wherein the journal segment 22 is disposed in the second cone inner bore 112, the bit leg 2 is internally penetrated with a bit leg inner bore 21, the bit leg inner bore 21 and the cone inner bore 11 are coaxially disposed, the pull rod 3 is penetrated in the bit leg inner bore 21 and the cone inner bore 11, the pull rod 3 and the bit leg 2 are connected by an adjusting fixing member 4, and the locking segment 12 is limited between the pull rod 3 and the bit leg 2. Specifically, the cutter teeth 14 are provided on the cone 1.

The embodiment of the application provides a pull rod locking bearing, wherein in the first embodiment, as shown in fig. 1 to 8, since the cone inner hole 11 comprises two sections, namely a first cone inner hole 111 and a second cone inner hole 112, and a locking section 12 is arranged between the first cone inner hole 111 and the second cone inner hole 112, the locking section 12 can be limited between a bit leg 2 and a pull rod 3 which are penetrated in a cone 1, namely the bit leg 2 and the pull rod 3 realize the relative fixation of the bit leg 2, the pull rod 3 and the cone 1 by clamping the locking section 12;

The pull rod 3 is connected with the bit leg 2 through the adjusting and fixing piece 4, the axial running amount of the cone 1 relative to the bit leg 2 can be adjusted through adjusting and fixing piece 4, after the axial running amount is adjusted to a certain value, the running amount of the cone 1 relative to the shaft neck of the bit leg 2 is reduced when the cone 1 rotates, the bearing stress state is improved, and the bearing service life is prolonged, so that the problems of abrasion of a steel ball and a steel ball runway under high bit pressure, large axial running amount in a steel ball locking structure and large cone running amount in the related art can be solved, and the abrasion of the steel ball and the steel ball runway is further aggravated.

In some alternative embodiments, referring to FIG. 4, bit leg 2 includes a journal segment 22 and a stop segment 23, the size of stop segment 23 along the radial direction of the journal segment is greater than the diameter of journal segment 22, and in conjunction with FIG. 1, journal segment 22 is threaded into second cone bore 112, stop segment 23 is located at the end face of cone 1, and the end of journal segment 22 remote from stop segment 23 is located at lock segment 12.

Specifically, as shown in connection with FIGS. 1 and 4, the end of journal segment 22 remote from spacing segment 23 has a bit leg thrust surface 221, and bit leg thrust surface 221 abuts the end of locking segment 12 facing second cone inner bore 112.

In some alternative embodiments, referring to fig. 1 and 5, the pull rod 3 includes a pull rod body 32 and a pull rod locking block 31, where the pull rod body 32 and the pull rod locking block 31 are connected, and as shown in fig. 6, the pull rod locking block 31 has a T-shape, and the diameter of the pull rod locking block 31 is larger than that of the pull rod body 32; referring to fig. 1, a pull rod body 32 is inserted into the bit leg inner hole 21, and a pull rod locking block 31 abuts against one end of the locking segment 12 facing the first cone inner hole 111.

Further, referring to fig. 1, the pull rod 3 is inserted into the bit leg inner hole 21 and the bit leg inner hole 11 from the first bit leg inner hole 111 toward the second bit leg inner hole 112, the pull rod locking block 31 abuts against one end of the locking section 12 toward the first bit leg inner hole 111, and the adjusting fixing member 4 is connected to one end of the pull rod body 32 far away from the pull rod locking block 31, thereby completing the relative fixation of the bit leg 1 and the bit leg 2.

Optionally, referring to fig. 5, the diameter of the pull rod locking block 31 is x, and in combination with fig. 2, the inner diameter of the second cone inner hole 112 is D1, the inner diameter of the locking segment 12 is D2, the inner diameter of the first cone inner hole 111 is D3, and the relationships among x, D1, D2, and D3 are: d1> D3> x > D2.

Specifically, the second cone inner bore 112 is the installation position of the journal segment 22 of the bit leg 2, so that the inner diameter of the second cone inner bore 112 is D1 maximum, the locking segment 12 is used for clamping the pull rod locking block 31 and the bit leg 2, so that the inner diameter D2 of the locking segment 12 is smaller than the inner diameter D1 of the second cone inner bore 112, the inner diameter D3 of the first cone inner bore 111 and the diameter x of the pull rod locking block 31; because the drawbar lock 31 is installed in the first cone bore 111, the diameter x of the drawbar lock 31 is smaller than the inner diameter D3 of the first cone bore 111.

Alternatively, referring to FIG. 2, where the thickness of locking segment 12 is h, and in combination with FIG. 7, rod lock 31 includes a rod lock surface 311, the side of journal segment 22 remote from spacing segment 23 is a leg stop surface 221, and when cone 1, rod 3, adjustment fixture 4 and leg 2 are assembled, the distance between rod lock surface 311 and leg stop surface 221 is C, C > h, i.e., rod lock 31, leg 2 are in clearance fit with cone 1 and have some axial play to allow cone 1 to rotate relative to leg 2. Optionally, the difference value between C and h is in the range of 0.1-0.6 mm. Alternatively, the difference between C and h is taken to be 0.4mm, and accordingly, the axial run-out is 0.4mm.

By adjusting the degree of tightness of the mounting of the retainer 4 and the pull rod 3, the distance C between the pull rod locking surface 311 and the bit leg thrust surface 221 can be adjusted, and the upward displacement of the cone 1 along the shaft journal of the bit leg 2 can be limited, so that the cone 1 is axially locked by the pull rod locking block 31.

In some alternative embodiments, referring to FIG. 4, bit leg bore 21 comprises a first bit leg bore 211 and a second bit leg bore 212, and the diameter of second bit leg bore 212 is greater than the diameter of first bit leg bore 211;

Further, as shown in fig. 5 and 7, the pull rod 3 includes a pull rod locking block 31, a pull rod body 32 and a thread section 33, the pull rod locking block 31 is abutted against one end of the locking section 12 facing to the first cone inner hole 111, the pull rod body 32 is penetrated in the bit leg inner hole 21, and the thread section 33 is located at one end of the pull rod body 32 far away from the pull rod locking block 31;

Referring again to fig. 6 and 7, the adjusting fixture 4 includes a lock nut 41, the lock nut 41 is screwed onto the threaded section 33, and the outer diameter of the lock nut 41 is larger than the diameter of the first bit leg inner hole 211. Because the diameter of second bit leg bore 212 is greater than the diameter of first bit leg bore 211, preferably, the diameter of lock nut 41 is equal to the inner diameter of second cone bore 112 to retain pull rod 3 in bit leg 2 and complete the axial retention of cone 1, bit leg 2, and pull rod 3 by the step formed by the difference in the inner diameters of first bit leg bore 211 and second bit leg bore 212.

Optionally, as shown in fig. 1 and 7, the adjusting fixing member 4 further includes a locking nut sealing member 42, where the locking nut 41 has a mounting groove, and when the locking nut 41 is screwed with the pull rod 3, the mounting groove is located at an end of the locking nut 41 away from the pull rod locking block 31, and the locking nut sealing member 42 is mounted in the mounting groove, and is optionally made of a rubber material, so as to achieve a sealing effect.

Alternatively, after the pull rod 3, lock nut 41 and bit leg 2 are assembled, lock nut 41 and bit leg 2 can be welded together to fix the amount of axial play.

In some alternative embodiments, referring to FIG. 1, a dynamic seal groove 13 is formed in second cone inner bore 112, and a dynamic seal ring 131 is disposed in dynamic seal groove 13. When the cone 1 and the bit leg 2 rotate relatively, the movable sealing ring 131 plays a sealing role between the cone and the bit leg.

In some alternative embodiments, as shown in FIGS. 1, 3 and 8, a shoulder 17 is provided in first cone inner bore 111, with sealing mandrel 5 mounted on shoulder 17; along the circumference of the sealing mandrel 5, a static sealing groove 16 is formed in the first cone inner hole 111, a static sealing ring 161 is arranged in the static sealing groove 16, and the static sealing ring 161 is in circumferential abutting connection with the sealing mandrel 5 and is used for sealing the sealing mandrel 5 in the first cone inner hole 111.

Optionally, as shown in fig. 3, a clamp spring groove 15 is further formed in the first cone inner hole 111, the clamp spring groove 15 is located at one side, far away from the locking section 12, of the static seal groove 16, and as shown in fig. 1, a clamp spring 151 is arranged in the clamp spring groove 15, and the clamp spring 151 abuts against one end, far away from the locking section 12, of the sealing mandrel 5, so that the sealing mandrel 5 is prevented from falling out of the first cone inner hole 111.

Further, the side of the sealing mandrel 5 remote from the tie rod 3 is provided with alloy teeth 51 to prevent wear of the sealing mandrel 5.

In some alternative embodiments, referring to fig. 1, the bit leg 2 is provided with a long oil hole 25 and an oil through hole 24 communicated with the long oil hole 25, and grease of an oil storage sealing device (not shown) arranged in the bit leg 2 can be introduced into a closed bearing cavity formed by the cone inner hole 11, the journal segment 22, the movable sealing ring 131, the static sealing ring 161 and the sealing mandrel 5 through the long oil hole 25 and the oil through hole 24, so that abrasion of the cone inner hole 11 and the journal segment 22 is reduced.

The present application also provides a second embodiment, as shown in fig. 9, which is different from the first embodiment in that an annular spacer 6 is added between the pull rod locking surface 311 and the roller locking surface 121, and a thrust spacer 7 is added between the bit leg thrust surface 221 and the roller thrust surface 122, specifically, the annular spacer 6 can reduce the abrasion between the pull rod locking surface 311 and the roller locking surface 121, and the thrust spacer 7 can reduce the abrasion between the bit leg thrust surface 221 and the roller thrust surface 122, so as to prolong the service lives of the roller 1 and the bit leg 2.

The third embodiment of the present application, as shown in fig. 10, is different from the first embodiment in that the surface of the locking piece 31 of the pull rod, which abuts against the locking section 12, is a conical surface. Specifically, as shown in fig. 10, that is, the pull rod locking surface 311 and the cone locking surface 121 are conical surfaces, the pull rod locking surface 311 is inclined upwards from the axial center of the pull rod 3 to the position away from the diameter increasing position of the pull rod 3, and the swinging amount of the cone 1 relative to the shaft neck of the bit leg 2 is further reduced through conical surface matching.

The pull rod locking bearing provided by the application has the following advantages:

1. By adjusting the lock nut 41, the axial movement of the cone 1 relative to the bit leg 2 can be adjusted, so that the axial movement is kept at a small value, the movement of the cone 1 relative to the shaft neck section 22 of the bit leg 2 is reduced, the stress state of the bearing is improved, and the service life of the bearing is prolonged;

2. The pull rod locking surface 311 is in surface contact with the roller locking surface 121, so that the contact area is large, the contact stress is low, pitting abrasion on the pull rod locking surface 311 and the roller locking surface 121 is reduced, the axial shifting amount of the roller 1 relative to the bit leg 2 is kept at a small level all the time, and the bearing life is further prolonged;

3. The length of the cone inner hole 11 is increased, the length of the bit leg shaft neck section 22 is increased, the contact surface of the cone inner hole 11 and the bit leg shaft neck section 22 is increased, the swing amplitude between the cone 1 and the bit leg 2 shaft neck section 22 is further reduced, the stress state of the bit leg shaft neck is improved, the bearing capacity of the cone 1 bearing for abnormal load is enhanced, and the bearing life is further prolonged.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present application and simplifying the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

It should be noted that in the present application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the application to enable those skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A tie rod lock bearing, comprising:

The inner part of the cone (1) is penetrated with a cone inner hole (11), the cone inner hole (11) comprises a first cone inner hole (111) and a second cone inner hole (112), and a locking section (12) is arranged between the first cone inner hole (111) and the second cone inner hole (112);

The bit leg (2) comprises a shaft neck section (22) and a limiting section (23), wherein the shaft neck section (22) is arranged in a second cone inner hole (112), a bit leg inner hole (21) penetrates through the bit leg (2), and the bit leg inner hole (21) and the cone inner hole (11) are coaxially arranged;

The pull rod (3) penetrates through the bit leg inner hole (21) and the cone inner hole (11), the pull rod (3) is connected with the bit leg (2) through the adjusting fixing piece (4), and the locking section (12) is limited between the pull rod (3) and the bit leg (2).

2. The tie rod lock bearing of claim 1 wherein:

The size of the limit section (23) of the bit leg (2) along the radial direction of the journal section (22) is larger than the diameter of the journal section (22), the journal section (22) is positioned in the second cone inner hole (112), and the limit section (23) is limited on the end surface of the cone (1);

The end of the shaft neck section (22) far away from the limiting section (23) is provided with a bit leg thrust surface (221), and the bit leg thrust surface (221) is abutted against one end of the locking section (12) facing the second cone inner hole (112).

3. The tie rod lock bearing of claim 1 wherein:

The pull rod (3) comprises a pull rod body (32) and a pull rod locking block (31), the diameter of the pull rod locking block (31) is larger than that of the pull rod body (32), the pull rod body (32) is arranged in the bit leg inner hole (21) in a penetrating mode, and the pull rod locking block (31) is abutted to one end, facing the first cone inner hole (111), of the locking section (12).

4. A tie rod lock bearing as claimed in claim 3 wherein:

The diameter of the pull rod locking block (31) is x, the inner diameter of the second cone inner hole (112) is D1, the diameter of the locking section (12) is D2, the inner diameter of the first cone inner hole (111) is D3, and the relation among the diameters x, D1, D2 and D3 is as follows: d1> D3> x > D2.

5. A tie rod lock bearing as claimed in claim 3 wherein:

The distance C between the pull rod locking block (31) and the bit leg (2) is greater than the thickness h of the locking section (12), and the value range of the difference value between C and h is 0.1-0.6 mm.

6. The tie rod lock bearing of claim 1 wherein:

The bit leg inner hole (21) comprises a first bit leg inner hole (211) and a second bit leg inner hole (212), and the diameter of the second bit leg inner hole (212) is larger than that of the first bit leg inner hole (211);

The pull rod (3) comprises a pull rod locking block (31), a pull rod body (32) and a thread section (33), wherein the pull rod locking block (31) is abutted against one end of the locking section (12) facing to the first cone inner hole (111), the pull rod body (32) is arranged in the bit leg inner hole (21) in a penetrating mode, and the thread section (33) is located at one end, far away from the pull rod locking block (31), of the pull rod body (32);

The adjusting and fixing piece (4) comprises a lock nut which is in threaded connection with the threaded section (33), and the outer diameter of the lock nut is larger than the diameter of the inner hole (211) of the first bit leg.

7. The tie rod lock bearing of claim 6 wherein:

One surface of the pull rod locking block (31) which is abutted against the locking section (12) is a conical surface.

8. The tie rod lock bearing of claim 1 wherein:

a movable sealing groove (13) is formed in the second cone inner hole (112), and a movable sealing ring (131) is arranged in the movable sealing groove (13).

9. The tie rod lock bearing of claim 1 wherein:

A shoulder (17) is arranged in the first cone inner hole (111), and a sealing mandrel (5) is arranged on the shoulder (17);

Along the circumference of sealing dabber (5), offer quiet seal groove (16) in first cone hole (111), be equipped with quiet sealing washer (161) in quiet seal groove (16), quiet sealing washer (161) with sealing dabber (5) circumference looks butt.

10. The tie rod lock bearing of claim 9 wherein:

A clamp spring groove (15) is formed in the first cone inner hole (111), and the clamp spring groove (15) is positioned at one side of the static seal groove (16) far away from the locking section (12);

The clamping spring groove (15) is internally provided with a clamping spring (151), and the clamping spring (151) is abutted to one end, far away from the locking section (12), of the sealing mandrel (5).