Economical brazed diamond single crystal bearing and preparation method thereof

Abstract

The invention discloses an economical brazed diamond single crystal bearing and a preparation method thereof, and belongs to the technical field of bearings, the bearing comprises a moving ring and a static ring, through sleeving or attaching of the moving ring and the static ring, diamond single crystal particles are brazed and fixed on a friction surface, or polycrystalline diamond compacts are combined, so that various sliding friction pairs are formed. The method has the remarkable advantages of simple and convenient technological operation, controllable production cost and the like, and solves the problems of high cost and poor universality of the existing PDC bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and particularly relates to an economical brazed diamond single crystal bearing and a preparation method thereof. Background Art

[0002] Downhole drill tools are the core equipment in the oil and gas exploitation field. Their performance directly affects the drilling efficiency, trajectory control accuracy, and the adaptability to complex formations, and they are the key technical equipment for the efficient development of deep oil and gas reservoirs and unconventional resources. Moreover, as an indispensable and important component of downhole power drill tools, bearings play a crucial role in their service life.

[0003] Currently, polycrystalline diamond compact bearings (PDC bearings) are widely used in downhole power drill tools such as turbodrills, positive displacement motors, and rotary steerable drill tools. PDC materials have advantages such as high hardness, high wear ratio, low friction coefficient, and high thermal conductivity. However, due to the extreme physical and chemical properties of diamond itself and the complex PDC synthesis process, the production cost is high, which to a certain extent limits its application in high-end industries, especially in the oil and gas drilling and production fields. Summary of the Invention

[0004] Aiming at the deficiencies existing in the prior art, the present invention provides an economical brazed diamond single crystal bearing and a preparation method thereof.

[0005] The present invention discloses an economical brazed diamond single crystal bearing, including a moving ring and a stationary ring that cooperates with the moving ring. The moving ring is sleeved inside the stationary ring. A first diamond single crystal friction surface is respectively fixed on the outer side surface of the moving ring and the inner side surface of the stationary ring. The two first diamond single crystal friction surfaces cooperate to form a first sliding friction pair.

[0006] Or, the moving ring and the stationary ring are in upper and lower contact. A first diamond single crystal friction surface is respectively fixed on the contact surface of the moving ring and the stationary ring. The two first diamond single crystal friction surfaces cooperate to form a second sliding friction pair.

[0007] Or, the moving ring is sleeved inside the stationary ring. At least one ring of polycrystalline diamond compacts is axially fixed on the inner side surface of the stationary ring. A first diamond single crystal friction surface is fixed on the outer side surface of the moving ring. The first diamond single crystal friction surface cooperates with all the polycrystalline diamond compacts to form a third sliding friction pair.

[0008] Or, the moving ring is sleeved inside the stationary ring. At least one ring of polycrystalline diamond compacts is axially fixed on the outer side surface of the moving ring. A first diamond single crystal friction surface is fixed on the inner side surface of the stationary ring. The first diamond single crystal friction surface cooperates with all the polycrystalline diamond compacts to form a fourth sliding friction pair.

[0009] As a further improvement of the present invention, when the bearing is provided with a third sliding friction pair, the moving ring is composed of a base body and a circular base sleeved at one end of the base body, the static ring is sleeved on the base body, and the bottom surface of the static ring abuts against the top surface of the circular base;

[0010] The first single-crystal diamond friction surface is fixed on the outer side surface of the base body, the second single-crystal diamond friction surface is fixed on the top surface of the circular base, and polycrystalline diamond compact is also fixedly distributed in a circular pattern on the bottom surface of the static ring; the second single-crystal diamond friction surface and all the polycrystalline diamond compacts cooperate to form a fifth sliding friction pair.

[0011] As a further improvement of the present invention, for the first and second sliding friction pairs, the two first single-crystal diamond friction surfaces are respectively fixed to the moving ring and the static ring by brazing;

[0012] For the third and fifth sliding friction pairs, the first single-crystal diamond friction surface and the second single-crystal diamond friction surface are respectively fixed to the base body and the circular base by brazing;

[0013] For the fourth sliding friction pair, the first single-crystal diamond friction surface is fixed to the static ring by brazing.

[0014] As a further improvement of the present invention, for the first, second, third, fourth and fifth sliding friction pairs, the thicknesses of the first single-crystal diamond friction surface and the second single-crystal diamond friction surface are 0.1-0.5 mm.

[0015] As a further improvement of the present invention, for the third and fifth sliding friction pairs, a plurality of first blind holes are axially arranged along the inner side surface of the static ring for at least one circle and the plurality of first blind holes in each circle are arranged at intervals, a plurality of second blind holes are arranged at intervals in a circular pattern at the bottom of the static ring, the polycrystalline diamond compact is welded in each of the first blind holes and the second blind holes, and the polycrystalline diamond compact protrudes from the inner side surface and the lower surface of the static ring.

[0016] As a further improvement of the present invention, for the fourth sliding friction pair, a plurality of third blind holes are axially arranged along the outer side surface of the moving ring for at least one circle and the plurality of third blind holes in each circle are arranged at intervals, the polycrystalline diamond compact is welded in each of the third blind holes, and the polycrystalline diamond compact protrudes from the outer side surface of the moving ring.

[0017] As a further improvement of the present invention, the shape of the polycrystalline diamond compact includes one of a cylindrical shape and a cubic shape;

[0018] The protruding height of the polycrystalline diamond compact is 0-3 mm.

[0019] The present invention discloses a preparation method of an economical brazed diamond single crystal bearing, which is applied to the above-mentioned economical brazed diamond single crystal bearing, and includes:

[0020] Select materials such as 4140, 4145H, 17-4PH or 4330V for machining the matrix blanks of the dynamic ring and the static ring to obtain the matrix blank of the dynamic ring and the matrix blank of the static ring;

[0021] Based on the matrix blank of the dynamic ring and the matrix blank of the static ring, spray abrasive adhesive on the surface where the diamond single crystal friction surface needs to be formed, and naturally dry for 10-60 minutes; machine blind holes at the matrix positions where the polycrystalline diamond composite sheets need to be formed;

[0022] Uniformly distribute diamond single crystal particles with a particle size of 20-200 meshes on the surface of the matrix coated with the adhesive, and uniformly coat or sprinkle silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal or cobalt-based brazing filler metal on the surface and voids of the diamond single crystal; and repeat the steps of spraying the adhesive and coating or sprinkling the brazing filler metal;

[0023] Brazing and fixing the polycrystalline diamond composite sheet in each blind hole;

[0024] Put the matrix blanks of the dynamic ring and the static ring after the diamond single crystal particles and the polycrystalline diamond composite sheets are distributed into a vacuum brazing furnace, and sinter at 500-900 °C for 10-90 minutes to finally obtain the dynamic ring and the static ring.

[0025] As a further improvement of the present invention, the adhesive is water-based or oil-based; it includes one of epoxy resin glue, phenolic resin glue, polyurethane-type adhesive, screen printing glue, polyvinyl alcohol-based adhesive, and inorganic silicate-based glue.

[0026] As a further improvement of the present invention, the silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal or cobalt-based brazing filler metal are all in a paste or powder state.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] By using brazed diamond single crystals to replace all or part of the diamond composite sheets, the present invention simplifies the synthesis process and reduces costs from the source of material production. At the same time, the brazing method is used to firmly fix the diamond single crystal friction surface on components such as the dynamic ring and the static ring, avoiding complex and expensive connection processes, further reducing the overall production cost, and breaking the cost limit that restricts its application in high-end industries, especially in the oil and gas drilling and production fields.

[0029] The present invention designs various mating methods between the moving ring and the stationary ring, such as the moving ring being sleeved inside the stationary ring or being in upper and lower contact, and reasonably distributes the single-crystal diamond friction surfaces and polycrystalline diamond compact sheets to form diversified sliding friction pairs, enabling the bearing to be flexibly selected according to different usage scenarios and working conditions, significantly improving the versatility and adaptability to complex working environments, and meeting the requirements of downhole power drill tools in various oil and gas exploitation operations.

[0030] The present invention gives full play to the characteristics of single-crystal diamond, such as high hardness, high wear ratio, low friction coefficient, and high thermal conductivity, and combines with the carefully designed sliding friction pair structure to effectively reduce friction loss, greatly improve the wear resistance and service life of the bearing, thereby enhancing the overall performance of downhole drill tools, ensuring the drilling efficiency and trajectory control accuracy, and enhancing the adaptability to complex formations. Brief Description of the Drawings

[0031] Figure 1 is the economical brazed single-crystal diamond bearing disclosed in Embodiment 1 of the present invention;

[0032] Figure 2 is the economical brazed single-crystal diamond bearing disclosed in Embodiment 2 of the present invention;

[0033] Figure 3 is the economical brazed single-crystal diamond bearing disclosed in Embodiment 3 of the present invention;

[0034] Figure 4 is the economical brazed single-crystal diamond bearing disclosed in Embodiment 3 of the present invention.

[0035] In the figure:

[0036] 1. Moving ring; 1-1. Substrate; 1-2. Circular base; 2. Stationary ring; 3. First single-crystal diamond friction surface; 4. Second single-crystal diamond friction surface; 5. First blind hole; 6. Polycrystalline diamond compact sheet; 7. Second blind hole; 8. Third blind hole. Detailed Description of the Embodiments

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] The present invention will be further described in detail below with reference to the drawings:

[0041] Embodiment 1:

[0042] As Figure 1 shown, the present invention provides an economical brazed diamond single crystal bearing, including a moving ring 1 and a stationary ring 2. Among them, the moving ring 1 and the stationary ring 2 are both circular rings as a whole. The moving ring 1 is sleeved inside the stationary ring 2. The outer side surface of the moving ring and the inner side surface of the stationary ring are respectively fixed with a first diamond single crystal friction surface 3. The first diamond single crystal friction surfaces 3 on both sides of the outer side surface of the moving ring 1 and the inner side surface of the stationary ring 2 cooperate to form a first sliding friction pair. In this embodiment, the first diamond single crystal friction surfaces 3 on both sides are respectively fixed to the moving ring 1 and the stationary ring 2 by brazing;

[0043] In this embodiment, preferably, the thickness of the first diamond single crystal friction surfaces 3 on both sides is 0.1 - 0.5 mm.

[0044] In this embodiment, preferably, the bearing formed by the moving ring 1 and the stationary ring 2 is a radial bearing.

[0045] The present invention provides a preparation method for an economical brazed diamond single crystal bearing, including:

[0046] Select materials such as 4140, 4145H, 17 - 4PH or 4330V for machining the matrix blanks of the moving ring 1 and the stationary ring 2 to obtain the moving ring matrix blank and the stationary ring matrix blank;

[0047] Based on the moving ring matrix blank and the stationary ring matrix blank, abrasive adhesives are sprayed on the outer side of the moving ring matrix blank and the inner side of the stationary ring matrix blank respectively, and then left to dry naturally for 10 - 60 minutes; the adhesive is either water-based or oil-based; it includes one of epoxy resin glue, phenolic resin glue, polyurethane-type adhesive, screen printing glue, polyvinyl alcohol-based adhesive, and inorganic silicate-based glue.

[0048] Diamond single crystal particles with a particle size of 20 - 200 mesh are evenly distributed on the surfaces of the moving ring matrix blank and the stationary ring matrix blank coated with the adhesive through a powder spreading machine, and brazing fillers such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal, or cobalt-based brazing filler metal are evenly coated or scattered on the surfaces and voids of the diamond single crystals; and the steps of spraying the adhesive and coating or scattering the brazing filler metal are repeated;

[0049] The moving ring matrix blank and the stationary ring matrix blank after the diamond single crystal particles are distributed are placed in a vacuum brazing furnace and sintered at 500 - 900 °C for 10 - 90 minutes to finally obtain the moving ring and the stationary ring.

[0050] In this embodiment, preferably, if the gaps between the diamond single crystal particles on the bearing surface are too large, the voids can also be filled by means of oxyacetylene flame spraying alloy powder, and then machining is carried out.

[0051] In this embodiment, preferably, the states of brazing fillers such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal, or cobalt-based brazing filler metal are all paste-like or powder-like.

[0052] Embodiment 2:

[0053] As Figure 2 shown, the present invention provides an economical brazed diamond single crystal bearing, including a moving ring 1 and a stationary ring 2. Among them, the moving ring 1 and the stationary ring 2 are both circular as a whole, and the moving ring 1 and the stationary ring 2 are arranged in a stacked manner up and down. First diamond single crystal friction surfaces 3 are respectively fixed on the mating surfaces of the moving ring 1 and the stationary ring 2, and the two first diamond single crystal friction surfaces 3 on both sides cooperate to form a second sliding friction pair; in this embodiment, the two first diamond single crystal friction surfaces 3 are respectively fixed to the moving ring 1 and the stationary ring 2 by brazing.

[0054] In this embodiment, preferably, the thicknesses of the two first diamond single crystal friction surfaces 3 are both 0.1 - 0.5 mm.

[0055] In this embodiment, preferably, the bearing formed by the moving ring 1 and the stationary ring 2 is a thrust bearing.

[0056] The present invention provides a preparation method for an economical brazed diamond single crystal bearing, including:

[0057] Select materials such as 4140, 4145H, 17-4PH or 4330V to machine the matrix blanks of the moving ring 1 and the stationary ring 2, obtaining the matrix blank of the moving ring and the matrix blank of the stationary ring;

[0058] Based on the matrix blank of the moving ring and the matrix blank of the stationary ring, spray abrasive adhesives on the mating surfaces of the matrix blank of the moving ring and the matrix blank of the stationary ring respectively, and let it dry naturally for 10 - 60 min; The adhesive is water-based or oil-based; It includes one of epoxy resin glue, phenolic resin glue, polyurethane adhesive, screen printing glue, polyvinyl alcohol glue, inorganic silicate glue.

[0059] Uniformly distribute diamond single crystal particles with a particle size of 20 - 200 mesh onto the surfaces of the matrix blank of the moving ring and the matrix blank of the stationary ring coated with the adhesive by a powder distributor, and evenly coat or sprinkle brazing filler metals such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal or cobalt-based brazing filler metal on the surface and voids of the diamond single crystal; And repeat the steps of spraying the adhesive and coating or sprinkling the brazing filler metal;

[0060] Put the matrix blank of the moving ring and the matrix blank of the stationary ring after distributing the diamond single crystal particles into a vacuum brazing furnace, sinter at 500 - 900 °C for 10 - 90 min to finally obtain the moving ring 1 and the stationary ring 2.

[0061] In this embodiment, preferably, if the gaps between the diamond single crystal particles on the bearing surface are too large, the voids can also be filled by oxyacetylene flame spraying alloy powder, and then machining is carried out.

[0062] In this embodiment, preferably, the states of brazing filler metals such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal or cobalt-based brazing filler metal are all paste-like or powder-like.

[0063] Embodiment 3:

[0064] As Figure 3 shown, the present invention provides an economical brazed diamond single crystal bearing, including a moving ring 1 and a stationary ring 2. Among them, the stationary ring 2 is integrally circular, and at least one circle of polycrystalline diamond composite sheets 6 is axially distributed along the inner side surface of the stationary ring 2. Each circle of polycrystalline diamond composite sheets 6 includes a plurality of polycrystalline diamond composite sheets 6 evenly spaced. A number of polycrystalline diamond composite sheets 6 are spaced and distributed along the bottom surface of the stationary ring 2.

[0065] In this embodiment, preferably, a plurality of first blind holes 5 are axially arranged along the inner side surface of the stationary ring 2 for at least one circle and the plurality of first blind holes 5 in each circle are spaced, and a plurality of second blind holes 7 are spaced and distributed along the bottom of the stationary ring 2. A polycrystalline diamond composite sheet 6 is welded in each first blind hole 5 and second blind hole 7, and the polycrystalline diamond composite sheet 6 protrudes from the inner side surface of the stationary ring 2 and the lower surface of the stationary ring 2.

[0066] In this embodiment, preferably, the shape of the polycrystalline diamond compact 6 includes one of a cylindrical shape and a cubic shape; when it is formed into a cylindrical shape, the diameter of the polycrystalline diamond compact 6 is 2 mm - 20 mm, the total height is 1 mm - 10 mm, and the exposed height is 0 - 3 mm.

[0067] In this embodiment, preferably, the polycrystalline diamond compacts 6 are all welded and fixed in the corresponding first blind hole 5 and second blind hole 7; the welding method includes one of vacuum brazing, high-frequency brazing, and flame brazing.

[0068] In this embodiment, preferably, the moving ring 1 includes a base body 1-1 that is integrally circular ring-shaped and a circular ring-shaped base 1-2. Among them, the circular ring-shaped base 1-2 is sleeved on one end of the base body 1-1. When the stationary ring 2 is sleeved on the moving ring 1, the stationary ring 2 is sleeved on the base body 1-1, and the bottom surface of the stationary ring 2 abuts against the top surface of the circular ring-shaped base 1-2. A first single-crystal diamond friction surface 3 is fixed on the outer side surface of the base body 1-1, and a second single-crystal diamond friction surface 4 is fixed on the top surface of the circular ring-shaped base 1-2. When the stationary ring 2 is sleeved on the moving ring 1, all the polycrystalline diamond compacts 6 located on the inner side surface of the stationary ring 2 cooperate with the first single-crystal diamond friction surface 3 located on the outer side surface of the base body 1-1 to form a third sliding friction pair; all the polycrystalline diamond compacts 6 located on the bottom surface of the stationary ring 2 cooperate with the second single-crystal diamond friction surface 4 located on the top surface of the circular ring-shaped base 1-2 to form a fifth sliding friction pair.

[0069] In this embodiment, preferably, the first single-crystal diamond friction surface 3 and the second single-crystal diamond friction surface 4 are distributed and fixedly connected to the outer side surface of the base body 1-1 and the top surface of the circular ring-shaped base 1-2 by brazing.

[0070] In this embodiment, preferably, the thickness of both the first single-crystal diamond friction surfaces 3 on both sides is 0.1 - 0.5 mm.

[0071] In this embodiment, preferably, the bearing formed by the moving ring 1 and the stationary ring 2 is a combined bearing.

[0072] The present invention provides a method for preparing an economical brazed single-crystal diamond bearing, including:

[0073] Select materials such as 4140, 4145H, 17-4PH, or 4330V for machining the base body blanks of the moving ring 1 and the stationary ring 2 to obtain the moving ring base body blank and the stationary ring base body blank;

[0074] Based on the dynamic ring matrix blank and the static ring matrix blank, abrasive adhesives are sprayed on the outer side of the corresponding matrix 1-1 position of the dynamic ring matrix blank and the top surface of the corresponding circular base 1-2, and then left to dry naturally for 10-60 minutes; the adhesive is water-based or oil-based; it includes one of epoxy resin glue, phenolic resin glue, polyurethane-type adhesive, screen printing glue, polyvinyl alcohol-based adhesive, and inorganic silicate-based glue; at least one circle of first blind holes 5 is arranged axially along the inner side of the static ring matrix blank, and a circle of second blind holes 7 is arranged annularly on the bottom surface of the static ring matrix blank;

[0075] Diamond single crystal particles with a particle size of 20-200 mesh are evenly powder-blasted onto the surface of the dynamic ring matrix blank coated with the adhesive, and brazing fillers such as silver-based active brazing filler, copper-based active brazing filler, nickel-based brazing filler, or cobalt-based brazing filler are evenly coated or sprinkled on the surface and voids of the diamond single crystal; and the steps of spraying the adhesive and coating or sprinkling the brazing filler are repeated;

[0076] Polycrystalline diamond compacts 6 are brazed and fixed in each of the first blind holes 5 and the second blind holes 7, and it is ensured that the polycrystalline diamond compacts 6 protrude from the inner side surface and the bottom surface of the static ring matrix blank;

[0077] After the diamond single crystal particles and the polycrystalline diamond compacts 6 are distributed on the dynamic ring matrix blank and the static ring matrix blank, they are placed in a vacuum brazing furnace and sintered at 500-900 °C for 10-90 minutes to finally obtain the dynamic ring 1 and the static ring 2.

[0078] In this embodiment, preferably, if the gaps between the diamond single crystal particles on the bearing surface are too large, the voids can also be filled by means of oxyacetylene flame spraying of alloy powder, and then machining is carried out.

[0079] In this embodiment, preferably, the states of brazing fillers such as silver-based active brazing filler, copper-based active brazing filler, nickel-based brazing filler, or cobalt-based brazing filler are all paste-like or powder-like.

[0080] Example 4:

[0081] As Figure 4 shown, the present invention provides an economical brazed diamond single crystal bearing, including a dynamic ring 1 and a static ring 2. Among them, both the dynamic ring 1 and the static ring 2 are circular rings, the dynamic ring 1 is sleeved inside the static ring 2, at least one circle of polycrystalline diamond compacts 6 is fixed along the axial direction of the outer side surface of the dynamic ring 1, and each circle of polycrystalline diamond compacts 6 includes a number of polycrystalline diamond compacts 6 arranged at intervals.

[0082] In this embodiment, preferably, multiple third blind holes 8 are axially arranged along the outer side surface of the moving ring 1 for at least one circle, and the multiple third blind holes 8 in each circle are spaced apart. The multiple third blind holes 8 are circumferentially arranged at intervals on the outer side surface of the moving ring 1. A polycrystalline diamond compact 6 is welded in each third blind hole 8, and the polycrystalline diamond compact 6 protrudes from the outer side surface of the moving ring 1.

[0083] In this embodiment, preferably, the shape of the polycrystalline diamond compact 6 includes one of a cylindrical shape and a cubic shape; when it is formed into a cylindrical shape, the diameter of the polycrystalline diamond compact 6 is 2 mm - 20 mm, the total height is 1 mm - 10 mm, and the exposed height is 0 - 3 mm.

[0084] In this embodiment, preferably, the polycrystalline diamond compacts 6 are all welded and fixed in the corresponding third blind holes 8; the welding method includes one of vacuum brazing, high-frequency brazing, and flame brazing.

[0085] In this embodiment, preferably, a first single-crystal diamond friction surface 3 is fixed on the inner side surface of the stationary ring 2, and the first single-crystal diamond friction surface 3 is fixed to the inner side surface of the stationary ring 2 by brazing. The thickness of the first single-crystal diamond friction surface 3 is 0.1 - 0.5 mm.

[0086] In this embodiment, the bearing formed by the moving ring 1 and the stationary ring 2 is a radial bearing.

[0087] The present invention provides a preparation method for an economical brazed single-crystal diamond bearing, including:

[0088] Select materials such as 4140, 4145H, 17 - 4PH, or 4330V for machining the matrix blanks of the moving ring 1 and the stationary ring 2 to obtain the moving-ring matrix blank and the stationary-ring matrix blank;

[0089] Based on the moving-ring matrix blank and the stationary-ring matrix blank, spray abrasive adhesive on the inner side surface of the stationary-ring matrix blank and air-dry it for 10 - 60 min; the adhesive is water-based or oil-based; it includes one of epoxy resin glue, phenolic resin glue, polyurethane-type adhesive, screen printing glue, polyvinyl alcohol-based adhesive, and inorganic silicate-based glue; arrange at least one circle of third blind holes 8 along the axial direction on the outer side surface of the moving-ring matrix blank;

[0090] Uniformly distribute diamond single-crystal particles with a particle size of 20 - 200 meshes onto the inner side surface of the stationary-ring matrix blank coated with the adhesive by a powder distributor, and uniformly coat or sprinkle brazing filler metals such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal, or cobalt-based brazing filler metal on the surface and voids of the diamond single crystals; and repeat the steps of spraying the adhesive and coating or sprinkling the brazing filler metal;

[0091] Brazing and fixing a polycrystalline diamond compact 6 in each third blind hole 8 and ensuring that the polycrystalline diamond compact 6 protrudes from the outer side surface of the moving-ring matrix blank;

[0092] After the dynamic ring matrix blank and the static ring matrix blank are cloth-fed with diamond single crystal particles and polycrystalline diamond composite sheets 6, they are placed in a vacuum brazing furnace and sintered at 500-900 °C for 10-90 minutes to finally obtain the dynamic ring 1 and the static ring 2.

[0093] In the above embodiment, preferably, if the gap between the diamond single crystal particles on the bearing surface is too large, the voids can also be filled by oxyacetylene flame spraying alloy powder, and then machining can be carried out.

[0094] In the above embodiment, preferably, the brazing materials such as silver-based active brazing filler metal, copper-based active brazing filler metal, nickel-based brazing filler metal or cobalt-based brazing filler metal are in a paste or powder state.

[0095] In the solutions of Embodiment 3 and Embodiment 4, the dynamic ring 1 and the static ring 2 adopt a combined structure of brazed diamond single crystal friction surface and polycrystalline diamond composite sheet, forming a "gradient wear" mechanism, which has the following advantages:

[0096] 1. Priority wear protection: Since the diamond single crystal friction surface will be worn preferentially, it will be damaged before the polycrystalline diamond composite sheet fails, so as to avoid the direct failure of the bearing;

[0097] 2. Low-cost maintenance: In actual replacement, only the dynamic ring or the static ring brazed with the diamond single crystal friction surface needs to be replaced, and the cost is much lower than replacing the entire bearing device;

[0098] 3. Protection of downstream equipment: The damage of the dynamic ring or the static ring brazed with the diamond single crystal friction surface will not affect the downstream equipment, while the damage of the dynamic ring or the static ring brazed with the polycrystalline diamond composite sheet will cause collateral damage to the downstream equipment.

[0099] Advantages of the present invention:

[0100] By using brazed diamond single crystal to replace all or part of the diamond composite sheet, the present invention simplifies the synthesis process and reduces the cost from the source of material production. At the same time, the diamond single crystal friction surface is firmly fixed on components such as the dynamic ring 1 and the static ring 2 by brazing, avoiding complex and expensive connection processes, further reducing the overall production cost, and breaking the cost limit that restricts its application in high-end industries, especially in the oil and gas drilling and production fields.

[0101] By designing various matching methods between the dynamic ring 1 and the static ring 2, such as the dynamic ring 1 being sleeved inside the static ring 2 or being attached up and down, and reasonably distributing the diamond single crystal friction surface and the polycrystalline diamond composite sheet 6, a diversified sliding friction pair is formed, enabling the bearing to be flexibly selected according to different usage scenarios and working conditions, significantly improving the versatility and the adaptability to complex working environments, and meeting the requirements of downhole motor drills in various oil and gas exploitation operations.

[0102] The present invention gives full play to the characteristics of single-crystal diamond, such as high hardness, high wear ratio, low friction coefficient, and high thermal conductivity, and combines with a carefully designed sliding friction pair structure to effectively reduce friction loss, greatly improve the wear resistance and service life of the bearing, thereby enhancing the overall performance of downhole drilling tools, ensuring drilling efficiency and trajectory control accuracy, and enhancing the adaptability to complex formations.

[0103] The process flow of the present invention is simple, and high-performance preparation of the bearing can be achieved under normal pressure conditions. Compared with the traditional method of synthesizing diamond composite sheets under high temperature and high pressure, it can greatly reduce energy consumption, and at the same time significantly reduce equipment investment and production costs.

[0104] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An economical brazed diamond single crystal bearing, comprising a moving ring and a stationary ring that cooperates with the moving ring, characterized in that, The moving ring is sleeved inside the stationary ring. The outer side surface of the moving ring and the inner side surface of the stationary ring are respectively fixed with a first single-crystal diamond friction surface, and the two first single-crystal diamond friction surfaces cooperate to form a first sliding friction pair; Alternatively, the moving ring and the stationary ring are attached to each other vertically. The mating surfaces of the moving ring and the stationary ring are respectively fixed with a first single-crystal diamond friction surface, and the two first single-crystal diamond friction surfaces cooperate to form a second sliding friction pair; Alternatively, the moving ring is sleeved inside the stationary ring. At least one circle of polycrystalline diamond compact is axially fixed on the inner side surface of the stationary ring. The outer side surface of the moving ring is fixed with a first single-crystal diamond friction surface, and the first single-crystal diamond friction surface cooperates with all the polycrystalline diamond compacts to form a third sliding friction pair; Alternatively, the moving ring is sleeved inside the stationary ring. At least one circle of polycrystalline diamond compact is axially fixed on the outer side surface of the moving ring. The inner side surface of the stationary ring is fixed with a first single-crystal diamond friction surface, and the first single-crystal diamond friction surface cooperates with all the polycrystalline diamond compacts to form a fourth sliding friction pair.

2. The economical brazed diamond single crystal bearing according to claim 1, wherein When the bearing has a third sliding friction pair, the moving ring is composed of a base body and a circular base sleeved at one end of the base body. The stationary ring is sleeved on the base body, and the bottom surface of the stationary ring abuts against the top surface of the circular base; The outer side surface of the base body is fixed with the first single-crystal diamond friction surface, the top surface of the circular base is fixed with a second single-crystal diamond friction surface, and the bottom surface of the stationary ring is also circumferentially fixed with polycrystalline diamond compacts; the second single-crystal diamond friction surface cooperates with all the polycrystalline diamond compacts to form a fifth sliding friction pair.

3. The economical brazed diamond single crystal bearing according to claim 2, wherein For the first and second sliding friction pairs, the two first single-crystal diamond friction surfaces are respectively fixed to the moving ring and the stationary ring by brazing; For the third and fifth sliding friction pairs, the first single-crystal diamond friction surface and the second single-crystal diamond friction surface are respectively fixed to the base body and the circular base by brazing; For the fourth sliding friction pair, the first single-crystal diamond friction surface is fixed to the stationary ring by brazing.

4. The economical brazed diamond single crystal bearing according to claim 2, wherein, For the first, second, third, fourth, and fifth sliding friction pairs, the thickness of the first single-crystal diamond friction surface and the second single-crystal diamond friction surface is 0.1 - 0.5 mm.

5. The economical brazed diamond single crystal bearing according to claim 2, characterized in that, For the third and fifth sliding friction pairs, a plurality of first blind holes are axially arranged in at least one circle along the inner side surface of the stationary ring, and the plurality of first blind holes in each circle are spaced apart. A plurality of second blind holes are circumferentially spaced apart at the bottom of the stationary ring. Each first blind hole and second blind hole is welded with a polycrystalline diamond compact, and the polycrystalline diamond compact protrudes from the inner side surface and the lower surface of the stationary ring.

6. The economical brazed diamond single crystal bearing according to claim 1, characterized in that, For the fourth sliding friction pair, a plurality of third blind holes are axially arranged in at least one circle along the outer side surface of the moving ring, and the plurality of third blind holes in each circle are spaced apart. Each third blind hole is welded with a polycrystalline diamond compact, and the polycrystalline diamond compact protrudes from the outer side surface of the moving ring.

7. The economical brazed diamond single crystal bearing according to claim 5 or 6, characterized in that, The shape of the polycrystalline diamond compact includes one of a cylindrical shape and a cubic shape; the protruding height of the polycrystalline diamond compact is 0 - 3 mm.

8. A preparation method of an economical brazed diamond single crystal bearing, which is used to manufacture the economical brazed diamond single crystal bearing according to any one of claims 1-7, characterized in that, It includes: Select materials such as 4140, 4145H, 17 - 4PH or 4330V for machining the matrix blanks of the dynamic ring and the static ring to obtain the dynamic ring matrix blank and the static ring matrix blank; Based on the dynamic ring matrix blank and the static ring matrix blank, spray abrasive adhesive on the surface where the single crystal diamond friction surface needs to be formed, and let it dry naturally for 10 - 60 min; machine blind holes at the matrix positions where the polycrystalline diamond compacts need to be formed; Uniformly distribute diamond single crystal particles with a mesh size of 20 - 200 on the matrix surface coated with the adhesive, and uniformly coat or sprinkle silver - based active brazing filler metal, copper - based active brazing filler metal, nickel - based brazing filler metal or cobalt - based brazing filler metal on the surface and voids of the diamond single crystal; And repeat the steps of spraying the adhesive and coating or sprinkling the brazing filler metal; Brazing - fix the polycrystalline diamond compact in each blind hole; Put the dynamic ring matrix blank and the static ring matrix blank after the distribution of the diamond single crystal particles and the polycrystalline diamond compacts into a vacuum brazing furnace, and sinter at 500 - 900 °C for 10 - 90 min to finally obtain the dynamic ring and the static ring.

9. The preparation method of the economical brazed diamond single crystal bearing according to claim 8, characterized in that, The adhesive is water - based or oil - based; it includes one of epoxy resin glue, phenolic resin glue, polyurethane - type adhesive, screen printing glue, polyvinyl alcohol - type adhesive, inorganic silicate - type glue.

10. The preparation method of the economical brazed diamond single crystal bearing according to claim 8, wherein, The states of the silver - based active brazing filler metal, copper - based active brazing filler metal, nickel - based brazing filler metal or cobalt - based brazing filler metal are all paste - like or powder - like.

Images