CN212028320U - Polycrystalline Diamond Radial Centralizing Sliding Bearings - Google Patents

Abstract

The utility model provides a polycrystalline diamond radial centering sliding bearing, comprising: a static ring and a moving ring, the static ring is sleeved on the outside of the moving ring, the static ring comprises a first base body with a first inner surface, and the first inner A first cast tungsten carbide layer is set outward on the surface, a plurality of first polycrystalline diamond friction parts are set on the first cast tungsten carbide layer, and one end of the first polycrystalline diamond friction part exposes the first cast tungsten carbide layer; the moving ring includes a The second substrate on the second outer surface, the second outer surface is provided with a second cast tungsten carbide layer, the second cast tungsten carbide layer is provided with a plurality of second polycrystalline diamond friction parts, and one end of the second polycrystalline diamond friction part is exposed the second cast tungsten carbide layer; the first polycrystalline diamond friction part and the second polycrystalline diamond friction part form a radial sliding friction pair. The polycrystalline diamond radial centering sliding bearing provided by the utility model has a long service life, low cost and high reliability.

Description

Polycrystalline Diamond Radial Centralizing Sliding Bearings

technical field

The utility model relates to the technical field of engineering components, in particular to a polycrystalline diamond radial centering sliding bearing.

Background technique

Oil and gas drilling downhole tools, especially turbo drilling tools, screw drilling tools, rotary steering, vertical drilling systems, downhole generators and other equipment are usually slender rod-shaped, with small radial dimensions and high ambient temperature and pressure. Small particles in the fluid (such as cuttings, quartz sand, etc.) enter the bearings of these devices, which can easily cause rapid wear and premature failure of the bearings. Bearing is an important part in downhole tools, and it is also a vulnerable part (the bearing relies on drilling fluid to cool and lubricate during operation, and its life is short). One of the main contents of downhole tool maintenance work is the replacement of radial centralizing bearings and axial thrust bearings.

In theory, the life of the downhole tool bearing should be synchronized with the life of the whole downhole tool, at least 300 hours to 600 hours. At present, the radial centering cemented carbide sliding bearing (commonly known as TC bearing) of the downhole tool is shown in Figure 1. The friction pair on the moving ring 2 and the static ring 1 is made of cemented carbide, which works on average under the cooling and lubricating conditions of the drilling fluid. The service life is only 150 hours to 200 hours, which is far from meeting the needs of downhole tools.

In addition, in order to improve the wear resistance of the friction pair material, the prior art also provides a PDC radial centering sliding bearing in a hydroelectric turbine system (strictly speaking, the bearing belongs to a self-aligning sliding bearing). First of all, the static ring 1 of the bearing is composed of a plurality of arc-shaped parts whose inner surfaces are inlaid or brazed with PDC composite friction parts. The arc radii of the inner friction surfaces of these parts are difficult to be consistent during processing, and the installation is troublesome and time-consuming. It is laborious, and the bearing accuracy is difficult to guarantee. Secondly, the PDC composite friction parts on the bearing static ring 1 and the dynamic ring 2 are inlaid or brazed in the through holes of the static ring 1 or the dynamic ring 2 base, and each PDC composite friction part corresponds to a through hole, reducing the The strength and stiffness of the matrix material are improved, the connection force between the PDC composite friction part and the matrix is greatly reduced, and the PDC composite friction part is easy to fall off from the through hole under the action of a large load (static load, dynamic load, high frequency vibration, etc.). .

Therefore, it is necessary to provide a new radial centering sliding bearing to better meet the needs of downhole tools.

It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present invention and facilitating the understanding of those skilled in the art; Parts are described and it is believed that the above technical solutions are well known to those skilled in the art.

Utility model content

In order to overcome at least one defect in the prior art, the utility model provides a polycrystalline diamond radial centering sliding bearing, which can not only ensure a long service life of the downhole tool, but also has low cost and high reliability, and can meet the requirements of the downhole tool. Comprehensive usage requirements of the tool.

In order to achieve the above purpose, the present invention provides the following technical solutions.

A polycrystalline diamond radial centralizing sliding bearing, the polycrystalline diamond radial centralizing sliding bearing includes: a static ring and a moving ring, the static ring is sleeved on the outside of the moving ring, and the static ring includes an overall an annular first base body, the first base body has an opposite first inner surface and a first outer cylindrical surface, the first inner surface is provided with a first cast tungsten carbide layer outwards, the first cast tungsten carbide A plurality of first polycrystalline diamond friction parts are arranged on the layer at intervals along the circumferential direction, and one end of the first polycrystalline diamond friction part exposes the first cast tungsten carbide layer; the moving ring comprises a ring-shaped as a whole. A second base body, the second base body has an opposing second inner cylindrical surface and a second outer surface, the second outer surface is provided with a second cast tungsten carbide layer inwardly, and the second cast tungsten carbide layer is along the circumference A plurality of second polycrystalline diamond friction parts are arranged at intervals, and one end of the second polycrystalline diamond friction parts exposes the second cast tungsten carbide layer; the first polycrystalline diamond friction parts and the second polycrystalline diamond friction parts are The crystalline diamond friction part forms a radial sliding friction pair.

In a preferred embodiment, the difference between the inner diameter of the stationary ring and the outer diameter of the moving ring is between 0.10 mm and 1.00 mm.

In a preferred embodiment, the stationary ring is provided with N circles of first polycrystalline diamond friction parts along the axial direction, wherein N is a positive integer greater than or equal to 1; the movable ring is provided with N rings along the axial direction The second polycrystalline diamond friction parts are circled, and the axial distance between the two adjacent circles of the first polycrystalline diamond friction parts is the same as the axial distance between the two adjacent circles of the second polycrystalline diamond friction parts.

In a preferred embodiment, when the polycrystalline diamond radial centralizing sliding bearing is installed on the uppermost and/or lowermost end of the rotary shaft of the downhole tool, N=2-3;

When the polycrystalline diamond radial centralizing sliding bearing is installed in the middle part of the rotary shaft of the downhole tool, N=1-2.

In a preferred embodiment, the first polycrystalline diamond friction part is cylindrical and has a first diameter; the second polycrystalline diamond friction part is cylindrical and cylindrical and has a second diameter, and the first polycrystalline diamond friction part is cylindrical and has a second diameter. The first diameter of a polycrystalline diamond friction part is between 4mm and 19mm, the total height is between 4mm and 14mm, and the exposed height is between 1mm and 3mm; the second diameter of the second polycrystalline diamond friction part is between Between 4mm and 19mm, the total height is between 4mm and 14mm, and the exposed height is between 1mm and 3mm.

In a preferred embodiment, the arc length of the central axis of the adjacent two first polycrystalline diamond friction parts in the circumferential direction is the same as the central axis of the adjacent two second polycrystalline diamond friction parts in the circumferential direction. The arc lengths are different; and the arc length of the central axis of the adjacent two first polycrystalline diamond friction parts in the circumferential direction is less than twice the first diameter, and the adjacent two second polycrystalline diamond The arc length of the central axis of the friction portion in the circumferential direction is less than twice the second diameter.

In a preferred embodiment, the total number of the first polycrystalline diamond friction parts in the circumferential direction of the same ring is different from the total number of the second polycrystalline diamond friction parts in the circumferential direction of the same ring by more than one.

In a preferred embodiment, the grain size of the cast tungsten carbide in the first cast tungsten carbide layer or the second cast tungsten carbide layer is 50 mesh to 200 mesh.

In a preferred embodiment, the material hardness of the first base body and the second base body is between HRC30˜HRC50.

In a preferred embodiment, the wear ratio of the polycrystalline diamond material of the first polycrystalline diamond friction part or the second polycrystalline diamond friction part reaches 5×10 ⁴ to 20×10 ⁴ .

beneficial effect

The embodiment of the present utility model provides a polycrystalline diamond radial centering sliding bearing, which has a longer working life compared with the existing TC bearing, and in addition, compared with the existing split PDC bearing static ring, the present application The static ring of the polycrystalline diamond radial centralizing sliding bearing is an integral structure, which can reduce the difficulty of processing and installation and improve the accuracy of the bearing. In addition, the polycrystalline diamond friction part on the static ring or the moving ring is fixed on the substrate by casting the tungsten carbide layer, during use, even under the action of large loads (static load, dynamic load, high-frequency vibration, etc.) Falling off will not occur, which improves the reliability of bearing operation.

With reference to the following description and drawings, specific embodiments of the invention are disclosed in detail, indicating the manner in which the principles of the invention may be employed. It should be understood that embodiments of the present invention are not thereby limited in scope.

Features described and/or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, in combination with, or instead of features in other embodiments .

It should be emphasized that the term "comprising/comprising" when used herein refers to the presence of a feature, integer, step or component, but does not exclude the presence or addition of one or more other features, integers, steps or components.

Description of drawings

The drawings described herein are for explanatory purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes and proportions of the components in the figures are only schematic and are used to help the understanding of the present invention, and do not specifically limit the shapes and proportions of the components of the present invention. Under the teaching of the present invention, those skilled in the art can select various possible shapes and proportions according to specific conditions to implement the present invention. In the attached image:

Fig. 1 is the structural representation of a kind of radially centralizing cemented carbide sliding bearing in the prior art;

2 is a schematic cross-sectional structural diagram of the polycrystalline diamond radial centralizing sliding bearing provided in the first embodiment of the present application;

Fig. 3 is a kind of polycrystalline diamond radial centralizing sliding bearing static ring sectional structure schematic diagram;

Fig. 4 is a kind of polycrystalline diamond radial centralizing sliding bearing moving ring sectional structure schematic diagram;

Figure 5 is a schematic diagram of a circumferentially developed structure of the inner surface of the inner surface of the static ring of a polycrystalline diamond radial centralizing sliding bearing;

Fig. 6 is a schematic diagram of the circumferentially unfolded structure of the outer surface of the moving ring of a polycrystalline diamond radially centralizing sliding bearing;

7 is a schematic cross-sectional structural diagram of the polycrystalline diamond radial centralizing sliding bearing provided in the second embodiment of the present application;

8 is a schematic cross-sectional structural diagram of the polycrystalline diamond radially centralizing sliding bearing provided in the third embodiment of the present application.

Description of reference numbers:

1. Static ring; 10. The first cast tungsten carbide layer; 11. The first substrate; 12. The first polycrystalline diamond friction part; 13. The first inner surface; 14. The first mosaic hole; 121. The first static ring friction ring; 122, the second static ring friction ring; 123, the third static ring friction ring;

2. Moving ring; 20. Second cast tungsten carbide layer; 21. Second substrate; 22. Second polycrystalline diamond friction part; 23. Second outer surface; 24. Second mosaic hole; 221. First moving ring friction ring; 222, the second moving ring friction ring; 223, the third moving ring friction ring.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, The described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to FIG. 2 to FIG. 6 , an embodiment of the present invention provides a polycrystalline diamond radial centering sliding bearing. The polycrystalline diamond radial centralizing sliding bearing may include: a static ring 1 and a moving ring 2 . The static ring 1 is sleeved on the outside of the moving ring 2 .

The static ring 1 includes an overall annular first base body 11, the first base body 11 has an opposite first inner surface 13 and a first outer cylindrical surface, the first inner surface 13 is provided with a first The cast tungsten carbide layer 10 is provided with a plurality of first polycrystalline diamond friction parts 12 at intervals along the circumferential direction, and one end of the first polycrystalline diamond friction part 12 is exposed to the first polycrystalline diamond friction part 12 . A cast tungsten carbide layer 10 . The moving ring 2 includes a second base body 21 which is annular as a whole. The second base body 21 has a second inner cylindrical surface and a second outer surface 23 opposite to each other. The second outer surface 23 is provided with a second inner surface. A cast tungsten carbide layer 20, the second cast tungsten carbide layer 20 is provided with a plurality of second polycrystalline diamond friction parts 22 at intervals along the circumferential direction, and one end of the second polycrystalline diamond friction part 22 is exposed to the second polycrystalline diamond friction part 22. Cast the tungsten carbide layer 20; the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 form a radial sliding friction pair.

In the present embodiment, the first polycrystalline diamond friction part 12 is connected to the first base 11 after transitioning through the first cast tungsten carbide layer 10 , and the second polycrystalline diamond friction part 22 passes through the second cast tungsten carbide layer. The layer 20 is connected to the second base 21 after the transition, which can improve the impact resistance of the polycrystalline diamond radially centralizing sliding bearing and prolong the service life.

The granularity of the cast tungsten carbide in the first cast tungsten carbide layer 10 or the second cast tungsten carbide layer 20 is 50 mesh to 200 mesh.

The first cast tungsten carbide layer 10 and the first polycrystalline diamond friction portion 12 may be welded together by copper alloy, nickel alloy or zinc alloy by using a pressureless dip sintering method. Specifically, the first cast tungsten carbide layer 10 may be formed with a plurality of first mosaic holes 14 for installing the first polycrystalline diamond friction portion 12 .

The second cast tungsten carbide layer 20 and the second polycrystalline diamond friction portion 22 may be welded together by copper alloy, nickel alloy or zinc alloy by using a pressureless dip sintering method. Specifically, the second cast tungsten carbide layer 20 may be formed with a plurality of second mosaic holes 24 for installing the second polycrystalline diamond friction portion 22 .

In this embodiment, the material hardness of the first base body 11 and the second base body 21 is between HRC30˜HRC50.

In general, the harder the material of the bearing base of the downhole tool, the better the better, but if the material used for the bearing base is too hard, it will lead to poor toughness and easy cracking. In this embodiment, the hardness of the materials of the first base body 11 and the second base body 21 is HRC30-HRC50, which can better meet the use requirements of downhole tool bearings. The wear ratio of the polycrystalline diamond material of the first polycrystalline diamond friction part 12 or the second polycrystalline diamond friction part 22 reaches 5×10 ⁴ to 20×10 ⁴ .

In this embodiment, the difference between the inner diameter of the static ring 1 and the outer diameter of the movable ring 2 is between 0.10 mm and 1.00 mm.

The main function of radial centralizing sliding bearings is to bear the radial load of the rotating shaft, and at the same time ensure that there is a sufficient safety distance (no direct contact) between other rotating parts on the shaft and other non-rotating parts in the equipment or device. For this reason, the difference between the inner diameter (diameter) of the static ring 1 and the outer diameter (diameter) of the moving ring 2 needs to be smaller than other rotating parts on the shaft and other non-rotating parts in the equipment or device during the entire operation of the equipment. minimum distance between. Experience has shown that under the premise that the rotating shaft is not stuck during operation, the smaller the difference, the smoother the rotating shaft will work (less vibration and noise); is larger, so the difference should be as small as possible when the device leaves the factory.

In one embodiment, the first polycrystalline diamond friction portion 12 is cylindrical and has a first diameter. The second polycrystalline diamond friction portion 22 is cylindrical and has a second diameter. Specifically, the first diameter is between 4 mm and 19 mm; the second diameter is between 4 mm and 19 mm.

The diameters of the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 may match the size of the bearing. When the bearing has a smaller diameter, the diameters of the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 can be selected with smaller diameters; when the bearing has a larger diameter, the first polycrystalline diamond The diameters of the friction part 12 and the second polycrystalline diamond friction part 22 may be larger in diameter.

The total height of the first polycrystalline diamond friction part 12 is between 4mm and 14mm, and the exposed height is between 1mm and 3mm; the total height of the second polycrystalline diamond friction part 22 is between 4mm and 14mm. The exposed height is between 1mm and 3mm.

The diameter range and height range of the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 are also related to the specific scene of their application. The polycrystalline diamond radial centralizing sliding bearing is mainly used in downhole tools. Downhole tools are usually slender rods, so the size of the bearing, especially the radial size of the bearing, is extremely limited. In addition, the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 are formed under high temperature and high pressure conditions, and their economical and applicable dimensions are no more than 20 mm in diameter and no more than 15 mm in height.

The range of the exposed height h mainly considers that the cooling and lubricating medium (drilling fluid) can flow smoothly through the bearing when the bearing is working underground, and at the same time considers the wear of the bearing for comprehensive optimization. With the gradual wear of the bearing, this exposed height becomes smaller and smaller until the exposed height disappears completely. When the exposed height h is between 1mm and 3mm, it can not only ensure the smooth circulation of the cooling and lubricating medium, but also have a long service life.

In one embodiment, due to the relative positional relationship between the moving ring 2 and the static ring 1, the arc length of the central axis of the adjacent two first polycrystalline diamond friction parts 12 in the circumferential direction is the same as that of the adjacent two The arc lengths of the central axis of the second polycrystalline diamond friction portion 22 in the circumferential direction are different.

If the distance (arc length) in the circumferential direction between the outer diameters (lips) of the two adjacent cylindrical polycrystalline diamond friction parts in the circumferential direction of the static ring 1 and the moving ring 2 is greater than the diameter of the cylindrical polycrystalline diamond friction part, the moving ring 2 is opposite to each other. When the static ring 1 rotates, the second polycrystalline diamond friction part 22 on the moving ring 2 will fall into the gap between the first polycrystalline diamond friction parts 12 of the static ring 1 . In order to prevent the above situation, in the embodiment of the present application, the arc length of the central axis of the adjacent two first polycrystalline diamond friction parts 12 in the circumferential direction is less than twice the first diameter, and the adjacent two adjacent The arc length of the central axis of the second polycrystalline diamond friction portion 22 in the circumferential direction is less than twice the second diameter.

If the number of the first polycrystalline diamond friction parts 12 on the static ring 1 is the same as the number of the second polycrystalline diamond friction parts 22 on the moving ring 2, when the moving ring 2 rotates, all the second polycrystalline diamond friction parts on the moving ring 2 The diamond friction part 22 will have a maximum contact area and a minimum contact area with all the first polycrystalline diamond friction parts 12 on the static ring 1 at the same time, so that the total contact area between the friction pair between the dynamic ring 2 and the static ring 1 will be larger. The amplitude fluctuates (that is, large for a while, small for a while), when the contact area is the smallest, the maximum contact stress received by the first polycrystalline diamond friction part 12 and the second polycrystalline diamond friction part 22 may reach or exceed the strength limit of the friction pair material, It will be damaged quickly and the bearing will not work properly.

In order to make the total contact area between the first polycrystalline diamond friction part 12 of the static ring 1 and the second polycrystalline diamond friction part 22 of the moving ring 2 only change slightly or remain basically unchanged during the operation of the bearing, the The total number of the first polycrystalline diamond friction parts 12 in the circumferential direction of the same ring is different from the total number of the second polycrystalline diamond friction parts 22 in the circumferential direction of the same ring by more than one.

In one embodiment, the stationary ring 1 is provided with N circles of first polycrystalline diamond friction parts 12 along its axial direction, where N is a positive integer greater than or equal to 1; N circles of second polycrystalline diamond friction parts 22 are arranged in the axial direction, and the axial spacing of two adjacent circles of first polycrystalline diamond friction parts 12 is the same as the axial spacing of two adjacent circles of second polycrystalline diamond friction parts 22 .

The polycrystalline diamond radial centralizing sliding bearing provided in the first embodiment is mainly used for the part where the radial force of the lower end of the output shaft of the downhole tool is particularly large, and a relatively ideal working life can be obtained. Please refer to Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, the polycrystalline diamond radial centralizing sliding bearing includes: a static ring 1 and a moving ring 2. The static ring 1 is sleeved on the outside of the dynamic ring 2, and three first polycrystalline diamond friction parts 12 are arranged on the inner surface of the static ring 1, which are the first static ring friction ring 121 and the second static ring friction ring 121 respectively. The ring friction ring 122 and the third static ring friction ring 123 . Three rings of second polycrystalline diamond friction parts 22 are provided on the outer surface of the moving ring 2 , which are respectively a first moving ring friction ring 221 , a second moving ring friction ring 222 and a third moving ring friction ring 223 . The axial distances between the central axes of the first polycrystalline diamond friction parts 12 of the two adjacent circles of the static ring 1 are H121 and H122 respectively, and the distance between the central axes of the two adjacent circles of the second polycrystalline diamond friction parts 22 of the dynamic ring 2 is H121 and H122 respectively. The axial distances H221 and H222 are equal.

The first static ring friction ring 121, the second static ring friction ring 122, and the third static ring friction ring 123 on all static rings 1 are respectively connected with the first dynamic ring friction ring 221, the second dynamic ring friction ring 221 on all dynamic rings 2, and the second dynamic ring The friction ring 222 and the third moving ring friction ring 223 correspond to each other and form a sliding friction pair.

Specifically, the parameters in the first embodiment can be: the inner diameter D1=100mm of the static ring 1, the outer diameter D2=99.5mm of the moving ring 2; the total height d1=7mm of the first polycrystalline diamond friction part 12, the first The total height d2=7mm of the dipolycrystalline diamond friction part 22, the exposed height h1=h2=1.5mm; the number of the first polycrystalline diamond friction part 12 in each circle of the static ring 1 is also 34 The size of the diamond friction part 12: Ф7×5mm), the number of the second polycrystalline diamond friction part 22 in each circle of the moving ring 2 is 33 (the size of the second polycrystalline diamond friction part 22: Ф7×5mm) ); the arc length S1=9.24mm of the central axis of the adjacent two first polycrystalline diamond friction parts 12 in the circumferential direction, and the circular arc of the central axis of the adjacent two second polycrystalline diamond friction parts 22 in the circumferential direction Length S2=9.47mm; the axial distance between the central axes of the first polycrystalline diamond friction parts 12 in the adjacent two circles of the static ring 1 and the central axis of the second polycrystalline diamond friction parts 22 in the adjacent two circles of the dynamic ring 2 The axial distances are equal, namely H121=H122=H221=H222=25mm.

Referring to Figure 3, Figure 4, Figure 5, Figure 6, and Figure 7, in the description of this application, for the part where the radial force in the middle of the rotary shaft of the downhole tool is relatively small, a second embodiment is provided to obtain a relatively ideal work. longevity while reducing costs.

A polycrystalline diamond radial centralizing sliding bearing provided in the second embodiment includes: a static ring 1 and a moving ring 2 . The static ring 1 is sleeved on the outside of the moving ring 2 . A circle of first polycrystalline diamond friction parts 12 is provided on the inner surface of the static ring 1 , and a circle of second polycrystalline diamond friction parts 22 is provided on the outer surface of the moving ring 2 . The first polycrystalline diamond friction parts 12 of all static rings 1 and the second polycrystalline diamond friction parts 22 of all dynamic rings 2 form a pair of sliding friction pairs.

The specific values of the parameters in this embodiment can refer to the above-mentioned first embodiment, respectively: D1=100mm, D2=99.5mm, d1=7mm, d2=7mm, h1=h2=1.5mm, the first The number of pieces (stripes) of the polycrystalline diamond friction part 12 is 34 (the size of the first polycrystalline diamond friction part 12: Ф7×5mm), and the number of the second polycrystalline diamond friction part 22 of the moving ring 2 is the same 33 pieces (the size of the second polycrystalline diamond friction part 22: Φ7×5mm), S1=9.24mm, S2=9.47mm.

3 , 4 , 5 , 6 , and 8 , in this embodiment, a third embodiment is provided for the part where the radial force on the upper end of the rotary shaft of the downhole tool is relatively large, so as to obtain a relatively ideal working life. and economic benefits.

A polycrystalline diamond radial centralizing sliding bearing provided in the third embodiment includes: a static ring 1 and a moving ring 2 . The static ring 1 is sleeved on the outside of the moving ring 2 . Two circles of first polycrystalline diamond friction parts 12 are arranged on the inner surface of the static ring 1, and two circles of second polycrystalline diamond friction parts 22 are arranged on the outer surface of the moving ring 2; The axial distance H121 between the central axes of the two adjacent circles of the first polycrystalline diamond friction parts 12 is equal to the axial distance H221 between the central axes of the two adjacent circles of the second polycrystalline diamond friction parts 22 of the moving ring 2 . The first polycrystalline diamond friction parts 12 of all static rings 1 and the second polycrystalline diamond friction parts 22 of all dynamic rings 2 form a pair of sliding friction pairs.

The specific values of the parameters of this embodiment can refer to the above-mentioned first embodiment, which are: D1=100mm, D2=99.5mm, d1=7mm, d2=7mm, h1=h2=1.5mm, and the The number of a polycrystalline diamond friction part 12 is 34 (the size of the first polycrystalline diamond friction part 12: Ф7×5mm), and the number of polycrystalline diamond friction parts in each circle of the moving ring 2 is also 33 (The size of the second polycrystalline diamond friction part 22: Φ7×5mm), S1=9.24mm, S2=9.47mm, H121=H221=25mm.

It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for description purpose and to distinguish similar objects, and there is no sequence between the two, nor can it be understood as an indication Or imply relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

The above are only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention according to the contents disclosed in the application documents.

Claims (10)

1. a polycrystalline diamond radial centralizing sliding bearing, is characterized in that, comprises: static ring and moving ring, The static ring is sleeved on the outside of the moving ring, and the static ring includes a first base body that is annular as a whole, the first base body has a first inner surface and a first outer cylindrical surface opposite to each other, and the first base body has a first inner surface and a first outer cylindrical surface. An inner surface is provided with a first cast tungsten carbide layer outward, and a plurality of first polycrystalline diamond friction parts are arranged on the first cast tungsten carbide layer at intervals along the circumferential direction. The first cast tungsten carbide layer is exposed at one end; The moving ring includes a second base body that is annular as a whole, the second base body has a second opposite inner cylindrical surface and a second outer surface, and the second outer surface is provided with a second cast tungsten carbide layer inward, so The second cast tungsten carbide layer is provided with a plurality of second polycrystalline diamond friction parts at intervals along the circumferential direction, and one end of the second polycrystalline diamond friction part is exposed to the second cast tungsten carbide layer; The crystalline diamond friction part and the second polycrystalline diamond friction part form a radial sliding friction pair. 2 . The polycrystalline diamond radial centralizing sliding bearing according to claim 1 , wherein the difference between the inner diameter of the stationary ring and the outer diameter of the moving ring is between 0.10 mm and 1.00 mm. 3 . 3 . The polycrystalline diamond radial centralizing sliding bearing according to claim 2 , wherein the stationary ring is provided with N circles of first polycrystalline diamond friction parts along the axial direction, wherein N is greater than or equal to 1. 4 . Positive integer; the moving ring is provided with N circles of second polycrystalline diamond friction parts along the axial direction, and the axial distance between the adjacent two circles of the first polycrystalline diamond friction parts is the same as that of the adjacent two circles of the second polycrystalline diamond friction parts The axial spacing is the same. 4. The polycrystalline diamond radial centralizing sliding bearing according to claim 3 is characterized in that, when the polycrystalline diamond radial centralizing sliding bearing is installed on the uppermost and/or lowermost part of the rotary shaft of the downhole tool, n=2-3; When the polycrystalline diamond radial centralizing sliding bearing is installed in the middle part of the rotary shaft of the downhole tool, N=1-2. 5. The polycrystalline diamond radial centralizing sliding bearing according to claim 2, wherein the first polycrystalline diamond friction part is cylindrical and has a first diameter; the second polycrystalline diamond friction part is in the shape of a cylinder. The cylindrical shape is cylindrical and has a second diameter, the first diameter of the first polycrystalline diamond friction part is between 4mm and 19mm, the total height is between 4mm and 14mm, and the exposed height is between 1mm and 3mm; The second diameter of the second polycrystalline diamond friction portion is between 4 mm and 19 mm, the total height is between 4 mm and 14 mm, and the exposed height is between 1 mm and 3 mm. 6. The polycrystalline diamond radial centralizing sliding bearing according to claim 5, wherein the arc length of the center axis of the first polycrystalline diamond friction part in the circumferential direction of the two adjacent two is the same as that of the adjacent two The arc lengths of the central axes of the second polycrystalline diamond friction parts in the circumferential direction are different; and the arc lengths of the central axes of the two adjacent first polycrystalline diamond friction parts in the circumferential direction are less than twice the length of the first circular arc. A diameter, the arc length of the central axes of the adjacent two second polycrystalline diamond friction parts in the circumferential direction is less than twice the second diameter. 7 . The polycrystalline diamond radial centralizing sliding bearing according to claim 6 , wherein the total number of the first polycrystalline diamond friction parts in the circumferential direction of the same ring is the same as the second polycrystalline diamond friction part. 8 . The total number in the circumferential direction of the same ring differs by more than 1. 8 . The polycrystalline diamond radially centralizing sliding bearing according to claim 1 , wherein the granularity of the cast tungsten carbide in the first cast tungsten carbide layer or the second cast tungsten carbide layer is 50 mesh to 200 mesh. 9 . 9 . The polycrystalline diamond radially centralizing sliding bearing according to claim 1 , wherein the material hardness of the first base body and the second base body is between HRC30˜HRC50. 10 . 10 . The polycrystalline diamond radial centralizing sliding bearing according to claim 1 , wherein the wear ratio of the polycrystalline diamond material of the first polycrystalline diamond friction part or the second polycrystalline diamond friction part reaches 10 . 5×10 ⁴ to 20×10 ⁴ .

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