A metal seal structure of a roller cone drill bit

Abstract

The application relates to a metal seal structure rolling cutter, belonging to the technical field of rolling cutters for reverse drilling machines. The rolling cutter comprises a cutter body, the cutter body comprising a main shaft and a rolling wheel rotatably connected to the main shaft, and seal end covers located in the rolling wheel and detachably connected to both ends of the main shaft; a sealing assembly, the sealing assembly comprising a first sealing ring statically sealed between the seal end cover and the main shaft, and a floating metal sealing ring dynamically sealed between the seal end cover and the rolling wheel. The rolling cutter utilizes the first sealing ring to statically seal the gap between the seal end cover and the main shaft, and utilizes the floating metal sealing ring to dynamically seal the gap between the seal end cover and the rolling wheel. Since the first sealing ring is statically sealed, the main shaft and the rolling wheel are prevented from being deformed and early failure due to relative rotation, the floating metal sealing ring has excellent properties of wear resistance, high-temperature resistance and aging resistance, thereby meeting the sealing performance of long-term relative rotation of the main shaft and the rolling wheel, and the service life of the rolling cutter is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of a rolling cutter drill bit for a reverse circulation drilling machine, in particular to a rolling cutter drill bit with a metal sealing structure. BACKGROUND

[0002] The reverse circulation drilling machine is widely used in underground transportation roadway and shaft construction under stable geological conditions. The reverse circulation drilling machine mainly drives a drilling tool system by a hydraulic motor to rotate a drill rod and a drill bit through a hydraulic transmission mode. Meanwhile, a push cylinder applies a drill bit with a pushing force when drilling and applies a cutter head with a counterforce when reaming.

[0003] The reverse circulation drilling machine is widely used in underground transportation roadway and shaft construction under stable geological conditions. The reverse circulation drilling machine mainly drives a drilling tool system by a hydraulic motor to rotate a drill rod and a drill bit through a hydraulic transmission mode. Meanwhile, a push cylinder applies a drill bit with a pushing force when drilling and applies a cutter head with a counterforce when reaming.

[0004] However, the reverse circulation rolling cutter drill bit is difficult to be effectively cooled in the reverse circulation construction, the bearing temperature is high, the rubber functional ring in the metal sealing assembly is permanently deformed, the sealing pre-tightening force is greatly reduced, and finally the sealing is early failure and leaks, which seriously affects the bearing life of the rolling cutter drill bit. SUMMARY

[0005] The rolling cutter drill bit with a metal sealing structure is provided in the embodiments of the application to solve the problem of poor sealing performance of the reverse circulation rolling cutter in the related art, which leads to early failure and leakage of the reverse circulation rolling cutter.

[0006] The rolling cutter drill bit with a metal sealing structure is provided in the embodiments of the application to solve the problem of poor sealing performance of the reverse circulation rolling cutter in the related art, which leads to early failure and leakage of the reverse circulation rolling cutter.

[0007] The drill bit body comprises a main shaft and a rolling cutter rotatably connected to the main shaft, and sealing end covers are detachably connected to both ends of the main shaft and located in the rolling cutter.

[0008] The sealing assembly comprises a first sealing ring that is statically sealed between the sealing end cover and the main shaft, and a floating metal sealing ring that is dynamically sealed between the sealing end cover and the rolling cutter.

[0009] In some embodiments, the floating metal sealing ring comprises a metal sealing static ring and a metal sealing dynamic ring that are sealingly connected to each other.

[0010] The metal sealing static ring is circumferentially positioned on the sealing end cover, and the metal sealing dynamic ring is circumferentially positioned on the rolling cutter.

[0011] In some embodiments: the sealing end cover is provided with a metal seal ring mounting groove near one end of the roller, and the metal seal ring mounting groove and the roller form an annular cavity accommodating the metal seal static ring and the metal seal dynamic ring.

[0012] In some embodiments: the metal seal static ring and the metal seal dynamic ring are each provided with an anti-rotation boss at a distal end thereof;

[0013] The metal seal ring mounting groove is provided with a first anti-rotation groove matching the anti-rotation boss of the metal seal static ring;

[0014] The roller is provided with a second anti-rotation groove matching the anti-rotation boss of the metal seal dynamic ring.

[0015] In some embodiments: the metal seal static ring and the metal seal dynamic ring are axially sealed between the sealing end cover and the roller;

[0016] The distal end of the metal seal static ring and the metal seal dynamic ring is provided with an elastic body axially elastically extruding the metal seal static ring and the metal seal dynamic ring.

[0017] In some embodiments: the elastic body is any one of a disc spring, a wave spring or a cylindrical helical spring.

[0018] In some embodiments: the metal seal static ring and the metal seal dynamic ring are each provided with an annular sealing groove at an outer periphery thereof;

[0019] The annular sealing groove of the metal seal static ring is provided with a second sealing ring radially sealing with the sealing end cover;

[0020] The annular sealing groove of the metal seal dynamic ring is provided with a third sealing ring radially sealing with the roller.

[0021] In some embodiments: the metal seal static ring and the metal seal dynamic ring are each provided with a metal sealing surface and an oil supply wedge surface at a proximal end thereof;

[0022] The metal sealing surface is deposited with any one of a diamond-like carbon coating, a boron carbide coating, a cubic boron nitride coating or a cermet coating.

[0023] In some embodiments: the thickness of the diamond-like carbon coating, the boron carbide coating, the cubic boron nitride coating or the cermet coating is 3-10 microns.

[0024] In some embodiments: the sealing end cover is provided with a through hole for oil injection or exhaust into the roller, and the through hole is connected with a plug for plugging the through hole.

[0025] In some embodiments: the main shaft is provided with an axial limiting shoulder for limiting the roller, and an inner hole of the roller is provided with a thrust surface in sliding connection with the limiting shoulder;

[0026] A surface of the limiting shoulder is surfaced with a WC wear-resistant alloy layer, and the thrust surface is subjected to carburizing quenching treatment.

[0027] In some embodiments: the inner hole of the roller is provided with a bearing cavity for accommodating a roller and / or a steel ball, and the main shaft is in rotary connection with the roller through the roller and / or the steel ball.

[0028] One end of the main shaft is provided with a plunger hole in communication with the bearing cavity, the plunger hole is slidably installed with a plunger, and one end of the plunger is provided with a plunger sealing groove.

[0029] The plunger sealing groove is provided with a fourth sealing ring in sealing connection with the plunger hole, and a width of the plunger sealing groove is greater than a cross-sectional diameter of the fourth sealing ring.

[0030] In some embodiments: an outer periphery of the sealing end cover is provided with a dustproof ring mounting groove, and the dustproof ring mounting groove is provided with a dustproof ring in interference connection with the roller.

[0031] The technical scheme provided by the application has the following beneficial effects:

[0032] The metal sealing structure's roller drill bit provided by the application is provided with a drill bit body, the drill bit body includes a main shaft and a roller in rotary connection with the main shaft, and both ends of the main shaft are detachably connected with a sealing end cover located in the roller.

[0033] Therefore, the metal sealing structure's roller drill bit provided by the application utilizes the first sealing ring to statically seal the gap between the sealing end cover and the main shaft, and utilizes the floating metal sealing ring to dynamically seal the gap between the sealing end cover and the roller. Since the first sealing ring is static sealing, the deformation of the main shaft and the roller caused by relative rotation is avoided, and early failure is avoided. The floating metal sealing ring has excellent properties of wear resistance, high temperature resistance and aging resistance, thereby meeting the sealing performance of long-term relative rotation of the main shaft and the roller, and improving the service life of the roller drill bit. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical scheme in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Figure 1 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0036] Figure 2 A cross-sectional view of a rolling cutter according to an embodiment of the present application; Figure 1 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0037] Figure 3 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0038] Figure 4 A cross-sectional view of a rolling cutter according to an embodiment of the present application; Figure 3 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0039] Figure 5 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0040] Figure 6 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0041] Figure 7 A cross-sectional view of a rolling cutter according to an embodiment of the present application; Figure 6 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0042] Figure 8 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0043] Figure 9 A cross-sectional view of a rolling cutter according to an embodiment of the present application; Figure 8 A cross-sectional view of a rolling cutter according to an embodiment of the present application;

[0044] Figure 10 A cross-sectional view of a rolling cutter according to an embodiment of the present application.

[0045] Reference signs:

[0046] 1. main shaft; 2. rolling wheel; 3. sealing end cover; 4. first sealing ring; 5. floating metal sealing ring; 6. dustproof ring; 7. bolt;

[0047] 11. limiting shaft shoulder; 12. plunger hole; 13. plunger; 14. fourth sealing ring; 15. large roller; 16. steel ball; 17. small roller;

[0048] 21. dustproof ring sealing surface; 22. third sealing ring sealing surface; 23. second anti-rotation groove; 24. thrust surface; 25. bearing cavity;

[0049] 31. metal sealing ring mounting groove; 32. first anti-rotation groove; 33. through hole; 34. dustproof ring mounting groove;

[0050] 51. metal sealing static ring; 52. metal sealing dynamic ring; 53. second sealing ring; 54. third sealing ring; 55. elastomer;

[0051] 511, metal sealing surface; 512, oil supply wedge surface; 513, anti-rotation boss; 514, annular sealing groove. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0053] The roller bit with the metal sealing structure provided in the embodiments of the present application can solve the problem of poor sealing performance of the reverse circulation roller, which leads to early failure and oil leakage of the reverse circulation roller.

[0054] Referring to FIGS. 1, 2, and 3, Figure 1 and Figure 2 The roller bit with the metal sealing structure provided in the embodiments of the present application can solve the problem of poor sealing performance of the reverse circulation roller, which leads to early failure and oil leakage of the reverse circulation roller.

[0055] The bit body includes a main shaft 1 and a roller 2 rotatably connected to the main shaft 1. Two sealing end covers 3 located in the roller 2 are detachably connected to both ends of the main shaft 1. The two ends of the main shaft 1 protrude outside the roller 2 and have a rectangular cross section. The middle part of the main shaft 1 is located inside the roller 2 and is rotatably connected to the roller 2 through a bearing.

[0056] The roller 2 has a hollow circular truncated cone structure. A plurality of rows of hard alloy teeth (not shown in the figure) are embedded on the outer periphery of the roller 2. Under the combined action of the hard alloy teeth on the roller 2 and the bottom rock, the roller 2 rotates around the main shaft 1. The hard alloy teeth on the roller 2 successively impact, extrude, and scrape the rock, causing the rock to break.

[0057] The two sealing end covers 3 are used to block the gap between the roller 2 and the two ends of the main shaft 1, respectively, to prevent the lubricating oil in the roller 2 from leaking or the rock debris outside the roller 2 from entering the roller 2. The two sealing end covers 3 are detachably fixed to the two ends of the main shaft 1 through bolts 7. Without disassembling the main shaft 1, the sealing components on the sealing end covers 3 can be easily maintained and replaced.

[0058] The sealing assembly includes a first sealing ring 4 statically sealed between the sealing end cover 3 and the main shaft 1, and a floating metal sealing ring 5 dynamically sealed between the sealing end cover 3 and the roller 2. The first sealing ring 4 is a rubber sealing ring, which is used to statically seal the gap between the sealing end cover 3 and the main shaft 1. The floating metal sealing ring 5 is used to dynamically seal the gap between the sealing end cover 3 and the roller 2.

[0059] The metal seal structure of the rolling cutter drill bit of the embodiment of the present application utilizes the first sealing ring 4 to seal the gap between the end cover 3 and the main shaft 1 by static sealing, and utilizes the floating metal sealing ring 5 to seal the gap between the end cover 3 and the roller 2 by dynamic sealing, so that the bearing cavity 25 formed between the main shaft 1 and the roller 2 is a closed oil storage chamber, thereby cooling and lubricating the bearing.

[0060] Since the first sealing ring 4 of the present application belongs to static sealing, the early failure of the main shaft 1 and the roller 2 caused by deformation during relative rotation is avoided, the floating metal sealing ring 5 has excellent properties of wear resistance, high temperature resistance and aging resistance, thereby meeting the sealing performance of the long-term relative rotation of the main shaft 1 and the roller 2, and the service life of the rolling cutter drill bit is improved.

[0061] In some optional embodiments: referring to Figure 2 The metal seal structure of the rolling cutter drill bit of the embodiment of the present application utilizes the first sealing ring 4 to seal the gap between the end cover 3 and the main shaft 1 by static sealing, and utilizes the floating metal sealing ring 5 to seal the gap between the end cover 3 and the roller 2 by dynamic sealing, so that the bearing cavity 25 formed between the main shaft 1 and the roller 2 is a closed oil storage chamber, thereby cooling and lubricating the bearing.

[0062] The metal seal structure of the rolling cutter drill bit of the embodiment of the present application utilizes the first sealing ring 4 to seal the gap between the end cover 3 and the main shaft 1 by static sealing, and utilizes the floating metal sealing ring 5 to seal the gap between the end cover 3 and the roller 2 by dynamic sealing, so that the bearing cavity 25 formed between the main shaft 1 and the roller 2 is a closed oil storage chamber, thereby cooling and lubricating the bearing.

[0063] The contact sealing surfaces of the metal seal static ring 51 and the metal seal dynamic ring 52 are flat, and the metal seal static ring 51 and the metal seal dynamic ring 52 are the same in structure and shape and are symmetrically arranged. The metal seal static ring 51 and the metal seal dynamic ring 52 are made of hard alloy material, stainless steel, or other metal materials, thereby improving the corrosion resistance, wear resistance, high temperature resistance and aging resistance of the metal seal static ring 51 and the metal seal dynamic ring 52.

[0064] In some optional embodiments: referring to Figures 2 to 4 The metal seal structure of the rolling cutter drill bit of the embodiment of the present application utilizes the first sealing ring 4 to seal the gap between the end cover 3 and the main shaft 1 by static sealing, and utilizes the floating metal sealing ring 5 to seal the gap between the end cover 3 and the roller 2 by dynamic sealing, so that the bearing cavity 25 formed between the main shaft 1 and the roller 2 is a closed oil storage chamber, thereby cooling and lubricating the bearing.

[0065] The metal seal ring mounting groove 31 is arranged on one end of the sealing end cover 3 close to the roller 2, the metal seal static ring 51 is located in the metal seal ring mounting groove 31, and the annular cavity is formed between the metal seal ring mounting groove 31 and the roller 2, which provides installation space for the metal seal static ring 51 and the metal seal dynamic ring 52 and limits the radial and axial positions of the metal seal static ring 51 and the metal seal dynamic ring 52, so that the metal seal static ring 51 and the metal seal dynamic ring 52 are reliably and slidingly connected.

[0066] In some optional embodiments, referring to Figures 3 to 7 and Figure 10 The metal seal structure rolling cutter provided by the embodiment of the application is provided with a plurality of circumferentially distributed anti-rotation bosses 513 at the ends away from each other of the metal seal static ring 51 and the metal seal dynamic ring 52, and the anti-rotation boss 513 is a circular arc boss protruding towards the axial direction of the metal seal static ring 51 and the metal seal dynamic ring 52.

[0067] A plurality of first anti-rotation grooves 32 suitable for the anti-rotation bosses 513 of the metal seal static ring 51 are arranged in the metal seal ring mounting groove 31, and the anti-rotation boss 513 of the metal seal static ring 51 is located in the first anti-rotation groove 32. A plurality of second anti-rotation grooves 23 suitable for the anti-rotation bosses 513 of the metal seal dynamic ring 52 are arranged in the roller 2, and the anti-rotation boss 513 of the metal seal dynamic ring 52 is located in the second anti-rotation groove 23.

[0068] The metal seal static ring 51 of the embodiment of the application is connected with the first anti-rotation groove 32 of the sealing end cover 3 through the anti-rotation boss 513, so as to limit the rotation of the metal seal static ring 51 on the sealing end cover 3. The metal seal dynamic ring 52 is connected with the second anti-rotation groove 23 of the roller 2 through the anti-rotation boss 513, so as to limit the rotation of the metal seal dynamic ring 52 on the roller 2.

[0069] In addition, the metal seal static ring 51 is connected with the first anti-rotation groove 32 of the sealing end cover 3 through the anti-rotation boss 513, and the metal seal dynamic ring 52 is connected with the second anti-rotation groove 23 of the roller 2 through the anti-rotation boss 513, so as to facilitate the regular maintenance and replacement of the metal seal static ring 51 and the metal seal dynamic ring 52 after wear and failure. Those skilled in the art can also realize the installation and fixation of the metal seal static ring 51 and the metal seal dynamic ring 52 through other connection modes (such as bolt connection, key pin connection or welding).

[0070] In some optional embodiments, referring to Figure 1 and Figure 2As shown, the rolling cutter drill bit with the metal sealing structure provided by the embodiment of the present application is characterized in that the metal sealing static ring 51 and the metal sealing dynamic ring 52 are axially sealed between the sealing end cover 3 and the roller 2. The ends of the metal sealing static ring 51 and the metal sealing dynamic ring 52 away from each other are provided with elastic bodies 55 axially extruding the metal sealing static ring 51 and the metal sealing dynamic ring 52.

[0071] The metal sealing static ring 51 and the metal sealing dynamic ring 52 of the embodiment of the present application are axially sealed between the sealing end cover 3 and the roller 2, and are both provided with the elastic bodies 55 at the ends away from each other, which are positioned in the annular cavity formed between the metal sealing ring mounting groove 31 and the roller 2.

[0072] The two elastic bodies 55 provide pre-tightening force at the two ends of the metal sealing static ring 51 and the metal sealing dynamic ring 52, so that the ends of the metal sealing static ring 51 and the metal sealing dynamic ring 52 away from each other are extruded and contacted with each other, and the metal sealing static ring 51 and the metal sealing dynamic ring 52 can be axially compensated after wearing, thereby ensuring the reliability of the sealing. The elastic body 55 is preferably but not limited to any one of a disc spring, a wave spring or a cylindrical helical spring.

[0073] In some optional embodiments, referring to Figures 2 to 7 and Figure 10 As shown, the rolling cutter drill bit with the metal sealing structure provided by the embodiment of the present application is characterized in that the metal sealing static ring 51 and the metal sealing dynamic ring 52 are axially sealed between the sealing end cover 3 and the roller 2. The ends of the metal sealing static ring 51 and the metal sealing dynamic ring 52 away from each other are provided with elastic bodies 55 axially extruding the metal sealing static ring 51 and the metal sealing dynamic ring 52.

[0074] The second sealing ring 53 is radially and statically sealed between the metal sealing static ring 51 and the side wall of the metal sealing ring mounting groove 31. The third sealing ring 54 is radially and statically sealed between the metal sealing dynamic ring 52 and the third sealing ring sealing surface 22 of the roller 2. The second sealing ring 53 blocks the gap between the metal sealing static ring 51 and the sealing end cover 3, and the third sealing ring 54 blocks the gap between the metal sealing dynamic ring 52 and the roller 2.

[0075] The second sealing ring 53 is in the annular sealing groove 514 of the metal sealing static ring 51 and rotates synchronously with the metal sealing static ring 51 and the sealing end cover 3, and the third sealing ring 54 is in the annular sealing groove 514 of the metal sealing dynamic ring 52 and rotates synchronously with the metal sealing dynamic ring 52 and the roller 2, so that the second sealing ring 53 and the third sealing ring 54 are both in a static sealing state, thereby improving the service life and sealing performance.

[0076] In some optional embodiments, referring toFigures 5 to 7 As shown in the drawings, the rolling cutter drill bit of the metal sealing structure provided by the embodiment of the present application is provided with a metal sealing static ring 51 and a metal sealing dynamic ring 52. The end of the metal sealing static ring 51 and the metal sealing dynamic ring 52 close to each other is provided with a metal sealing surface 511 and an oil supply wedge surface 512. The metal sealing static ring 51 and the metal sealing dynamic ring 52 are connected by sliding sealing with each other by means of the metal sealing surface 511. The oil supply wedge surface 512 is a slope surface for supplying the lubricating oil in the bearing cavity 25 to the metal sealing surface 511, so as to provide lubrication and cooling for the metal sealing surface 511.

[0077] The width of the annular band of the metal sealing surface 511 is 1.5-3.5 mm. The metal sealing surface 511 is deposited with any one of a diamond-like carbon coating, a boron carbide coating, a cubic boron nitride coating and a cermet coating. The thickness of the diamond-like carbon coating, the boron carbide coating, the cubic boron nitride coating and the cermet coating is 3-10 microns. The diamond-like carbon coating, the boron carbide coating, the cubic boron nitride coating and the cermet coating all have the performance of low friction coefficient, high hardness and good wear resistance, so as to reduce the wear of the metal sealing static ring 51 and the metal sealing dynamic ring 52.

[0078] In some optional embodiments, referring to Figure 3 and Figure 4 As shown in the drawings, the rolling cutter drill bit of the metal sealing structure provided by the embodiment of the present application is provided with a metal sealing static ring 51 and a metal sealing dynamic ring 52. The end of the metal sealing static ring 51 and the metal sealing dynamic ring 52 close to each other is provided with a metal sealing surface 511 and an oil supply wedge surface 512. The metal sealing static ring 51 and the metal sealing dynamic ring 52 are connected by sliding sealing with each other by means of the metal sealing surface 511. The oil supply wedge surface 512 is a slope surface for supplying the lubricating oil in the bearing cavity 25 to the metal sealing surface 511, so as to provide lubrication and cooling for the metal sealing surface 511.

[0079] In some optional embodiments, referring to Figure 1 , Figures 8 to 10 As shown in the drawings, the rolling cutter drill bit of the metal sealing structure provided by the embodiment of the present application is provided with a metal sealing static ring 51 and a metal sealing dynamic ring 52. The end of the metal sealing static ring 51 and the metal sealing dynamic ring 52 close to each other is provided with a metal sealing surface 511 and an oil supply wedge surface 512. The metal sealing static ring 51 and the metal sealing dynamic ring 52 are connected by sliding sealing with each other by means of the metal sealing surface 511. The oil supply wedge surface 512 is a slope surface for supplying the lubricating oil in the bearing cavity 25 to the metal sealing surface 511, so as to provide lubrication and cooling for the metal sealing surface 511.

[0080] In order to make the contact stress of the floating metal sealing ring 5 relatively stable, the reliability of the sealing is higher, and the service life of the sealing is longer, the embodiment of the present application is provided with a limiting shaft shoulder 11 of the main shaft 1 for limiting the roller 2 in the axial direction, and a thrust surface 24 of the inner hole of the roller 2 is in sliding connection with the limiting shaft shoulder 11, so as to bear the axial thrust during the working of the rolling cutter drill bit. In order to reduce the adhesive wear of the thrust surface 24, the surface of the limiting shaft shoulder 11 is coated with a WC wear-resistant alloy, and the thrust surface 24 is subjected to carburizing quenching treatment to form a hardened layer.

[0081] In some optional embodiments, referring toFigure 1 , Figures 8 to 10 As shown in the figure, this application embodiment provides a hobbing drill bit with a metal sealing structure. The inner hole of the roller 2 of the hobbing drill bit has a bearing cavity 25 that accommodates a large roller 15, a small roller 17, and a steel ball 16. The diameter of the large roller 15 is larger than the diameter of the small roller 17. The large roller 15 is located on one side of the large end of the roller 2, the small roller 17 is located on one side of the small end of the roller 2, and the steel ball 16 is located between the large roller 15 and the small roller 17. The spindle 1 and the roller 2 are rotatably connected by the large roller 15, the small roller 17, and the steel ball 16.

[0082] A plug hole 12 communicating with the bearing cavity 25 is provided at one end of the main shaft 1 near the large end of the roller 2. The plug hole 12 is an oblique hole forming a set angle with the axis of the main shaft 1. A plug pin 13 is slidably installed in the plug hole 12, and a plug pin sealing groove is provided at one end of the plug pin 13. A fourth sealing ring 14 is provided in the plug pin sealing groove and is sealed to the plug hole 12. The width of the plug pin sealing groove is larger than the cross-sectional diameter of the fourth sealing ring 14, so that the fourth sealing ring 14 can slide axially in the plug pin sealing groove, thereby adjusting the pressure of the bearing cavity 25.

[0083] In some alternative embodiments: see Figure 1 , Figure 2 , Figure 4 and Figure 10 As shown, this application embodiment provides a rotary drill bit with a metal sealing structure. The outer periphery of the sealing end cap 3 of the rotary drill bit is provided with a dustproof ring mounting groove 34. A dustproof ring 6 is provided in the dustproof ring mounting groove 34 and is interference-connected with the roller 2. The dustproof ring 6 is sealed between the sealing end cap 3 and the roller 2.

[0084] Both ends of the inner bore of roller 2 are provided with a first stepped hole and a second stepped hole. The diameter of the first stepped hole is larger than that of the second stepped hole. The hole wall of the first stepped hole is configured as a dustproof ring sealing surface 21 that seals with the dustproof ring 6, and the hole wall of the second stepped hole is configured as a third sealing ring sealing surface 22 that seals with the third sealing ring 54. The dustproof ring 6 between the sealing end cap 3 and roller 2 is used to prevent rock debris from entering the annular cavity that accommodates the metal sealing stationary ring 51 and the metal sealing dynamic ring 52.

[0085] Working principle

[0086] This application provides a rotary drill bit with a metal sealing structure. The rotary drill bit with the metal sealing structure of this application is provided with a drill bit body, which includes a spindle 1 and a roller 2 rotatably connected to the spindle 1. Both ends of the spindle 1 are detachably connected to a sealing end cap 3 located inside the roller 2. The sealing assembly includes a first sealing ring 4 that is statically sealed between the sealing end cap 3 and the spindle 1, and a floating metal sealing ring 5 that is dynamically sealed between the sealing end cap 3 and the roller 2.

[0087] Therefore, the metal seal structure of the present application utilizes the first sealing ring 4 to seal the gap between the end cover 3 and the main shaft 1 in static sealing, and utilizes the floating metal sealing ring 5 to seal the gap between the end cover 3 and the roller 2 in dynamic sealing. Since the first sealing ring 4 belongs to static sealing, the deformation of the main shaft 1 and the roller 2 caused by relative rotation is avoided, and the early failure is avoided. The floating metal sealing ring 5 has excellent properties of wear resistance, high temperature resistance and aging resistance, thereby meeting the sealing performance of the long-term relative rotation of the main shaft 1 and the roller 2, and improving the service life of the roller cutter.

[0088] In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0089] It should be noted that in the present application, relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0090] The above description is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A metal-sealed structure of a roller cone drill bit, characterized by, The drill bit body comprises a main shaft (1) and a roller (2) rotatably connected to the main shaft (1), and a sealing end cover (3) is detachably connected to both ends of the main shaft (1) and located in the roller (2). The sealing assembly comprises a first sealing ring (4) statically sealed between the sealing end cover (3) and the main shaft (1), and a floating metal sealing ring (5) dynamically sealed between the sealing end cover (3) and the roller (2). The floating metal sealing ring (5) comprises a metal sealing static ring (51) and a metal sealing dynamic ring (52) which are slidably connected to each other. The metal sealing static ring (51) is circumferentially positioned on the sealing end cover (3), and the metal sealing dynamic ring (52) is circumferentially positioned on the roller (2). The metal sealing static ring (51) and the metal sealing dynamic ring (52) are axially sealed between the sealing end cover (3) and the roller (2). The metal sealing static ring (51) and the metal sealing dynamic ring (52) are provided with an elastic body (55) at one end away from each other, which axially elastically extrudes the metal sealing static ring (51) and the metal sealing dynamic ring (52). The outer ring of the metal sealing static ring (51) and the metal sealing dynamic ring (52) is provided with an annular sealing groove (514). The annular sealing groove (514) of the metal sealing static ring (51) is provided with a second sealing ring (53) which is radially statically sealed with the sealing end cover (3). The annular sealing groove (514) of the metal sealing dynamic ring (52) is provided with a third sealing ring (54) which is radially statically sealed with the roller (2).

2. The metal sealing structure's hobbing drill bit of claim 1, wherein: The sealing end cover (3) is provided with a metal sealing ring mounting groove (31) at one end close to the roller (2), and the metal sealing ring mounting groove (31) and the roller (2) form an annular cavity accommodating the metal sealing static ring (51) and the metal sealing dynamic ring (52).

3. The metal sealing structure's hobbing drill bit of claim 2, wherein: The metal sealing static ring (51) and the metal sealing dynamic ring (52) are each provided with an anti-rotation boss (513) at one end away from each other; The metal sealing ring mounting groove (31) is provided with a first anti-rotation groove (32) matching the anti-rotation boss (513) of the metal sealing static ring (51); The roller (2) is provided with a second anti-rotation groove (23) matching the anti-rotation boss (513) of the metal sealing dynamic ring (52).

4. The metal sealing structure's hobbing drill bit of claim 1, wherein: The elastic body (55) is any one of a disc spring, a wave spring or a cylindrical coil spring.

5. The metal sealing structure's hobbing drill bit of claim 1, wherein: The metal sealing static ring (51) and the metal sealing dynamic ring (52) are provided with a metal sealing surface (511) and an oil supply wedge surface (512) at one end close to each other; The metal sealing surface (511) is deposited with any one of a diamond-like carbon coating, a boron carbide coating, a cubic boron nitride coating or a metal ceramic coating. ​ The thickness of the diamond-like coating, boron carbide coating, cubic boron nitride coating, and cermet coating is 3-10 microns.

6. A roller cone drill bit of the metal seal structure according to claim 1, wherein: The main shaft (1) is provided with a limiting shaft shoulder (11) for limiting the roller (2) in the axial direction, and the inner hole of the roller (2) is provided with a thrust surface (24) in sliding connection with the limiting shaft shoulder (11); The surface of the limiting shaft shoulder (11) is coated with a WC wear-resistant alloy layer, and the thrust surface (24) is subjected to carburizing and quenching treatment.

7. A roller cone drill bit of the metal seal structure according to claim 1, wherein: The inner hole of the roller (2) is provided with a bearing cavity (25) for accommodating a roller and / or a steel ball (16), and the main shaft (1) is rotatably connected with the roller (2) through the roller and / or the steel ball (16); One end of the main shaft (1) is provided with a plug hole (12) in communication with the bearing cavity (25), and the plug hole (12) is slidably provided with a plug (13), and one end of the plug (13) is provided with a plug sealing groove; The plug sealing groove is provided with a fourth sealing ring (14) in sealing connection with the plug hole (12), and the width of the plug sealing groove is greater than the cross-sectional diameter of the fourth sealing ring (14).

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