Articulating bearing and method for monitoring the state of an articulating bearing based on the frictional volt effect

Abstract

This invention discloses a spherical plain bearing and a method for monitoring the condition of the spherical plain bearing based on the triboelectric effect. The spherical plain bearing includes an outer ring, an inner ring, a self-lubricating gasket, and a wear-resistant coating. The inner ring is located inside the outer ring, the outer ring has a first surface facing the inner ring, and the inner ring has a second surface facing the outer ring. The self-lubricating gasket is conductive and is located on one of the first and second surfaces. The wear-resistant coating has semiconductor properties and is located on the other of the first and second surfaces. The self-lubricating gasket and the wear-resistant coating are in contact. The inner and outer rings move relative to each other, causing the self-lubricating gasket and the wear-resistant coating to rub against each other and output a DC signal. This invention can generate a DC signal through friction during the relative movement of the inner and outer rings, and then reflect the operating state of the spherical plain bearing through the characteristic parameters of the DC signal, achieving real-time condition monitoring. It features high integration, high signal-to-noise ratio, and reliable monitoring data.

Description

Technical Field

[0001] This invention belongs to the field of bearing technology, specifically relating to a spherical plain bearing and a method for monitoring the condition of the spherical plain bearing based on the triboelectric effect. Background Technology

[0002] Self-lubricating spherical plain bearings are highly integrated in the category of sliding bearings. Their core structure includes the inner ring, the outer ring, and a solid lubricating layer embedded between the spherical surfaces. They are widely used in key fields such as aerospace, automotive industry, water conservancy facilities, and military equipment.

[0003] Self-lubricating spherical plain bearings in related technologies may fail due to various factors during operation, including wear fracture, fatigue crack, and fatigue fracture. These failure modes pose a serious threat to the safe operation of equipment. The condition monitoring of self-lubricating spherical plain bearings in related technologies is generally achieved by monitoring changes in indirect parameters such as friction torque and friction temperature. The signals collected by these methods have a low signal-to-noise ratio and may have a certain lag, making it difficult to perform real-time condition monitoring. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a highly integrated joint bearing that enables real-time monitoring.

[0006] Embodiments of the present invention also propose a method for monitoring the condition of joint bearings based on the triboelectric effect.

[0007] The spherical bearing of this invention includes:

[0008] An outer ring and an inner ring, the inner ring being disposed inside the outer ring, the outer ring having a first surface facing the inner ring, and the inner ring having a second surface facing the outer ring; A self-lubricating pad, wherein the self-lubricating pad is conductive, and the self-lubricating pad is disposed on one of the first surface and the second surface; A wear-resistant coating having semiconductor properties is disposed on the other of the first surface and the second surface. A self-lubricating pad is in contact with the wear-resistant coating. The inner ring and the outer ring move relative to each other to cause the self-lubricating pad and the wear-resistant coating to rub against each other and output a DC signal.

[0009] The embodiments of the present invention can generate a DC signal through friction during the relative movement of the inner and outer rings, and then reflect the operating status of the spherical bearing through the characteristic parameters of the DC signal, thereby realizing real-time status monitoring. The invention has high overall integration, high signal-to-noise ratio, and reliable monitoring data.

[0010] In some embodiments, the self-lubricating pad is a woven composite pad, and the self-lubricating pad is modified to make it conductive.

[0011] In some embodiments, the modification treatment method for the self-lubricating pad includes: preparing an aqueous conductive solution containing a conductive material, and immersing the self-lubricating pad in the aqueous conductive solution; Remove the self-lubricating pad that has absorbed the aqueous conductive solution and dry it to obtain a self-lubricating pad with conductive properties.

[0012] In some embodiments, the self-lubricating pad comprises a composite matrix woven from PTFE fibers and Kevlar aramid, or the self-lubricating pad comprises a composite matrix woven from PTFE fibers and Nomex aramid.

[0013] In some embodiments, the self-lubricating pad is disposed on the first surface, and the wear-resistant coating is disposed on the second surface.

[0014] In some embodiments, the self-lubricating pad is adhered to the first surface by an adhesive that is conductive.

[0015] In some embodiments, the adhesive comprises a mixed binder and a conductive material.

[0016] In some embodiments, the wear-resistant coating is formed on the second surface by a surface deposition process; and / or, the wear-resistant coating includes a diamond-like carbon coating or a molybdenum disulfide coating.

[0017] In some embodiments, the wear-resistant coating is prepared using the outer ring or the inner ring as a substrate and the first surface of the outer ring or the second surface of the inner ring as a base, employing a physical vapor deposition method. The preparation process of the wear-resistant coating includes: The substrate is placed in a physical vapor deposition apparatus; A transition layer is sputtered onto the substrate of the substrate; Argon and acetylene gases are introduced into the physical vapor deposition apparatus, with argon as the sputtering medium and acetylene as the carbon and hydrogen sources, to deposit a hydrogenated amorphous carbon coating with semiconductor properties on the surface of the substrate.

[0018] In some embodiments, the transition layer is a chromium layer; And / or, the thickness of the transition layer is 0.6 micrometers to 1.5 micrometers; And / or, the thickness of the hydrogenated amorphous carbon coating is 2 micrometers to 4 micrometers.

[0019] In some embodiments, the inner ring may swing or rotate relative to the outer ring about at least one of a first direction, a second direction, and a third direction, wherein each of the first direction, the second direction, and the third direction has a preset angle between each other. And / or, the spherical bearing includes a first terminal and a second terminal, the first terminal being electrically connected to the outer ring and the second terminal being electrically connected to the inner ring, the first terminal and the second terminal being used to output the DC signal.

[0020] The joint bearing condition monitoring method based on the friction volt effect of this invention is used to monitor the condition of the joint bearing described in any of the above embodiments. The condition monitoring method includes: Acquire the DC signal generated under the triboelectric effect when the inner and outer rings of the spherical bearing move relative to each other; Based on the DC signal, a correlation model is constructed between the characteristic parameters in the DC signal and the operating state of the spherical bearing; The DC signal of the spherical plain bearing under operating conditions is acquired in real time, and the operating status of the spherical plain bearing is monitored based on the correlation model.

[0021] In some embodiments, the characteristic parameters of the DC signal include at least one of peak voltage, charge transfer amount, and signal fluctuation coefficient; And / or, the operating condition of the spherical bearing includes at least one of bearing wear, lubrication failure, and remaining life. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a joint bearing according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the outer ring of the spherical bearing according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the inner ring in a spherical bearing according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of friction volt generation using a joint bearing according to an embodiment of the present invention.

[0026] Figure 5 This is a flowchart illustrating the preparation process of the self-lubricating pad and adhesive according to an embodiment of the present invention.

[0027] Figure 6 This is a voltage output curve diagram of the joint bearing in an embodiment of the present invention when it moves around the Z-axis.

[0028] Figure 7 This is a voltage output curve diagram of the joint bearing of this invention when it moves around the X-axis or Y-axis.

[0029] Figure 8 This is a process flow diagram of the preparation process of the wear-resistant coating according to an embodiment of the present invention.

[0030] Figure label: 100. Spherical plain bearing; 1. Outer ring; 11. First surface; 2. Inner ring; 21. Second surface; 3. Self-lubricating gasket; 4. Wear-resistant coating. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below, with examples of the embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] See Figures 1 to 8 The following describes a spherical bearing 100 and a spherical bearing condition monitoring method based on the triboelectric effect according to an embodiment of the present invention.

[0033] See Figures 1 to 4 The spherical bearing 100 of this embodiment includes an outer ring 1, an inner ring 2, a self-lubricating gasket 3, and a wear-resistant coating 4. The inner ring 2 is disposed inside the outer ring 1. The outer ring 1 has a first surface 11 facing the inner ring 2, and the inner ring 2 has a second surface 21 facing the outer ring 1. The first surface 11 of the outer ring 1 is also the inner surface of the outer ring 1, and the second surface 21 of the inner ring 2 is also the outer surface of the inner ring 2.

[0034] The self-lubricating pad 3 is conductive and is disposed on one of the first surface 11 and the second surface 21. The self-lubricating pad 3 not only provides continuous lubrication but also transmits electrical signals. The wear-resistant coating 4 has semiconductor properties and is disposed on the other of the first surface 11 and the second surface 21. The self-lubricating pad 3 and the wear-resistant coating 4 are in contact. The inner ring 2 and the outer ring 1 move relative to each other, causing the self-lubricating pad 3 and the wear-resistant coating 4 to rub against each other and output a DC electrical signal. For example, the self-lubricating pad 3 is disposed on the inner surface of the outer ring 1, and the wear-resistant coating 4 is disposed on the outer surface of the inner ring 2. The self-lubricating pad 3 is fixed to the inner surface of the outer ring 1, covering the inner surface of the outer ring 1. The self-lubricating pad 3 can be the same size as the first surface 11 and be completely fitted and fixed, so that the inner ring 2 can effectively adhere to and rub against the self-lubricating pad 3 when moving relative to the outer ring 1.

[0035] Based on the triboelectric effect, a direct current signal is generated by the mutual friction between the self-lubricating gasket 3 bonded to the inner surface of the outer ring 1 of the spherical plain bearing 100 and the wear-resistant coating 4 with semiconductor properties on the outer surface of the inner ring 2. This electrical signal generated by the relative movement and friction of the inner ring 2 and the outer ring 1 of the bearing has a strong coupling relationship with the motion state of the bearing and a quantitative mapping relationship. The electrical signal changes synchronously with the working state (such as speed and load) of the spherical plain bearing 100. Therefore, the operating state of the spherical plain bearing 100 can be monitored and fault diagnosis can be performed by analyzing the triboelectric voltage signal generated during the bearing operation. This provides a more direct and effective means for condition monitoring and fault diagnosis of the spherical plain bearing 100, and enables online monitoring of the operating state and prediction of the remaining life of the spherical plain bearing 100, providing a new technical approach for intelligent operation and maintenance of major equipment.

[0036] The embodiments of the present invention can generate a DC signal through friction during the relative movement of the inner ring 2 and the outer ring 1, and then reflect the operating status of the spherical bearing 100 through the characteristic parameters of the DC signal, thereby realizing real-time status monitoring. The overall integration is high, the signal-to-noise ratio is high, and the monitoring data is reliable.

[0037] The monitoring method of this invention features high real-time performance and accuracy, achieving direct sensing based on the triboelectric effect. It offers three major advantages: real-time monitoring, direct perception, and structural integration, effectively overcoming the shortcomings of traditional indirect monitoring methods such as lag and low signal-to-noise ratio. This invention can construct a quantitative correlation model between the characteristic parameters of the triboelectric signal (peak voltage, charge transfer, signal fluctuation coefficient, etc.) and bearing wear and lubrication failure, enabling online assessment of the operating status and prediction of the remaining life of the spherical plain bearing 100. This provides a new technical path for the intelligent operation and maintenance of critical equipment.

[0038] This invention can acquire the DC signal generated by friction of the spherical bearing 100 at different oscillation frequencies, thereby reflecting the operating status of the spherical bearing 100 and realizing real-time monitoring. While realizing in-situ monitoring, it can also achieve self-powering without the need for additional power supply equipment. The DC power generated by friction can be directly used to power small signal transmission devices or collected and stored.

[0039] The embodiments of the present invention have a high degree of integration and can be monitored based on the original structure of the spherical bearing 100 without the need to install sensors or other auxiliary equipment. They are highly practical. This application adds additional functions with minimal modifications and does not affect the motion performance of the original spherical bearing 100.

[0040] See Figure 5 In some embodiments, the self-lubricating pad 3 is a woven composite pad, and the self-lubricating pad 3 is modified to make it conductive.

[0041] Furthermore, the modification method for the self-lubricating pad 3 includes: preparing an aqueous conductive solution containing a conductive material, immersing the self-lubricating pad 3 in the aqueous conductive solution, wherein the conductive material can be graphene or other materials with excellent conductivity; the immersion time can be 5 to 15 minutes to ensure that the aqueous conductive solution containing graphene fully wets the self-lubricating pad 3. During the immersion process, the graphene material can be more fully dispersed within the self-lubricating pad 3.

[0042] Remove the self-lubricating pad 3 that has absorbed the aqueous conductive solution and dry it. The self-lubricating pad 3 can be dried by natural air drying. The drying temperature is between 15 degrees Celsius and 25 degrees Celsius, and the drying time can be between 40 minutes and 80 minutes to obtain a self-lubricating pad 3 with conductive properties.

[0043] In this embodiment, the self-lubricating pad 3 is conductive, so the DC signal generated by friction can be transmitted to the outer ring 1 through the self-lubricating pad 3 and then transmitted out, which facilitates the acquisition of DC signal.

[0044] In some embodiments, the self-lubricating pad 3 comprises a composite matrix woven from PTFE fibers and Kevlar aramid, or the self-lubricating pad 3 comprises a composite matrix woven from PTFE fibers and Nomex aramid. The self-lubricating pad 3 provides continuous lubrication. It can become conductive after modification. The self-lubricating pad 3 can also be made from other materials with continuous lubrication properties and further modified.

[0045] See Figure 5 In some embodiments, the self-lubricating pad 3 is adhered to the first surface 11 by an adhesive that is conductive. In this embodiment, the self-lubricating pad 3 is adhered to the inner surface of the outer ring 1 by an adhesive that is conductive, thereby ensuring a stable output of the DC signal.

[0046] Furthermore, the adhesive includes a mixed binder and a conductive material, wherein the conductive material can be in powder or granule form, which facilitates uniform distribution of the conductive material and binder after mixing, ensuring the conductivity of the adhesive. The conductive material can be a conductor material powder or a semiconductor material powder, such as graphene powder or other materials with conductive properties, thereby making the adhesive conductive. After the self-lubricating pad 3 is bonded to the inner surface of the outer ring 1 by the adhesive, the DC signal generated by friction can be output through the self-lubricating pad 3 and the outer ring 1, ensuring the reliability of the monitoring data and the stability of the overall connection.

[0047] Taking graphene powder as an example, during the preparation of the binder, graphene powder can be added to the phenolic resin binder and stirred for 20 to 40 minutes using a stirrer such as a magnetic stirrer to ensure that the graphene powder and the phenolic resin binder are fully and evenly mixed together.

[0048] When attaching the self-lubricating gasket 3 to the inner surface of the outer ring 1, apply the adhesive evenly to the surface of the self-lubricating gasket 3. After bonding the self-lubricating gasket 3 to the inner surface of the outer ring 1, heat to cure. The outer ring 1 and the self-lubricating gasket 3 can be placed in a drying oven at a temperature of 150°C to 200°C for 1 hour to 2.5 hours to ensure that the outer ring 1 and the self-lubricating gasket 3 are fully bonded and fixed together.

[0049] In this embodiment of the spherical plain bearing 100, the inner ring 2 can be made of hardened bearing steel, such as GCr15 or GCr15SiMn. The outer ring 1 is bonded with a self-lubricating gasket 3 made of fiber and aramid braid. After modification treatment, the self-lubricating gasket 3 possesses electrical conductivity. The self-lubricating gasket 3 is bonded and fixed to the inner surface of the outer ring 1 by an adhesive. The adhesive serves to bond and enhance the strength of the gasket. A certain mass fraction of graphene powder is doped into the adhesive, giving it a certain degree of electrical conductivity.

[0050] The wear-resistant coating 4 of the inner ring 2 has semiconductor properties. Therefore, based on the triboelectric effect, the bearing converts the mechanical energy generated by the relative motion between the inner ring 2 and the outer ring 1 of the self-lubricating spherical bearing 100 into a DC electrical signal for output. In this embodiment, the triboelectric effect refers to the friction between the graphene-modified self-lubricating pad 3 with metallic conductive properties adhered to the inner surface of the outer ring 1 and the wear-resistant coating 4 with semiconductor properties deposited on the outer surface of the inner ring 2, thereby generating a DC voltage.

[0051] During the operation of the spherical plain bearing 100, the bearing's operating status can be directly converted into a DC electrical signal and output, thereby enabling real-time monitoring of the status.

[0052] See Figure 3 and Figure 4 In some embodiments, the wear-resistant coating 4 is formed on the second surface 21 by a surface deposition process, and the wear-resistant coating 4 includes diamond-like coating, molybdenum disulfide coating, etc.

[0053] In this embodiment, the wear-resistant coating 4 can be formed on the outer surface of the inner ring 2 by physical vapor deposition. It can have high hardness, low friction characteristics, good wear resistance, and semiconductor characteristics, thereby generating a DC signal based on the triboelectric effect.

[0054] Optionally, the diamond-like carbon (DLC) coating has extremely high hardness, typically ranging from 60 GPa to over 110 GPa, approaching or partially reaching the level of diamond. Simultaneously, it possesses excellent tribological properties, exhibiting an extremely low coefficient of friction (0.04-0.2) and outstanding wear resistance, serving as a self-lubricating coating to improve the contact lubrication effect between the inner ring 2 and the outer ring 1.

[0055] Alternatively, the diamond-like coating can be a hydrogenated amorphous carbon coating.

[0056] See Figure 8 In some embodiments, the outer ring or inner ring is used as the substrate, and the first surface of the outer ring or the second surface of the inner ring is used as the base, and a physical vapor deposition method is employed to prepare the wear-resistant coating. This embodiment describes the specific process method using a hydrogenated amorphous carbon coating as an example, with the wear-resistant coating located on the second surface of the inner ring.

[0057] The preparation process of wear-resistant coatings includes: The substrate (inner ring) is placed in a physical vapor deposition apparatus.

[0058] A transition layer is sputtered onto the substrate (second surface) of the substrate. The transition layer can be a chromium layer. The transition layer can relieve interfacial stress and enhance the adhesion between the wear-resistant coating and the substrate, thereby improving the structural stability and quality of the wear-resistant coating and ensuring the service life of the spherical bearing.

[0059] Furthermore, the thickness of the chromium layer can range from 0.6 micrometers to 1.5 micrometers. For example, the thickness of the chromium layer can be 0.6 micrometers, 0.85 micrometers, 0.9 micrometers, 0.94 micrometers, 1 micrometer, 1.2 micrometers, 1.36 micrometers, or 1.5 micrometers. By rationally controlling the thickness of the chromium layer, its comprehensive performance in complex environments can be optimized, enhancing the synergistic protective capabilities of wear resistance and corrosion resistance, and improving the stability and quality of the wear-resistant coating.

[0060] Argon and acetylene gases are then introduced into a physical vapor deposition apparatus, with argon as the sputtering medium and acetylene as the carbon and hydrogen sources, to deposit a hydrogenated amorphous carbon coating with semiconductor properties on the surface of the substrate. The wear-resistant coating thus prepared has both excellent tribological properties and the semiconductor properties required to generate the tribovolt effect.

[0061] Optionally, the thickness of the hydrogenated amorphous carbon coating in this embodiment is 2 micrometers to 4 micrometers. For example, the thickness of the hydrogenated amorphous carbon coating is 2 micrometers, 2.3 micrometers, 2.8 micrometers, 3 micrometers, 3.2 micrometers, 3.45 micrometers, or 4 micrometers. By reasonably controlling the thickness of the hydrogenated amorphous carbon coating, this embodiment can balance the bonding strength between the coating and the substrate, the service life of the wear-resistant coating, and the protective effect. It avoids the coating from being too thin, which would lead to insufficient bonding between the coating and the substrate and thus cause the coating to peel off. At the same time, it can avoid the hydrogenated amorphous carbon coating from being too thick, which would lead to excessive internal residual stress.

[0062] In some embodiments, the inner ring 2 can swing or rotate relative to the outer ring 1 about at least one of a first direction, a second direction, and a third direction, and there is a preset angle between each pair of the first direction, the second direction, and the third direction.

[0063] Optionally, the first direction is parallel to the axis of the outer ring 1, and the first, second, and third directions are orthogonal to each other. The first direction can be the Z-axis as shown in the figure, the second direction can be the X-axis as shown in the figure, and the third direction can be the Y-axis as shown in the figure.

[0064] The DC electrical signals generated by the friction of the spherical bearing under different oscillation frequencies in the embodiments of the present invention are as follows: Figure 6 and Figure 7 As shown, where, Figure 6 The graph shows the output DC signal of the spherical bearing when it oscillates around the Z-axis. Figure 7 The graph shows the output DC signal of the spherical bearing when it oscillates around the Y-axis or X-axis.

[0065] The self-lubricating spherical plain bearing 100 of the present invention can adapt to various working conditions, including but not limited to oscillation or rotation around a first direction, a second direction, a third direction, or other movable directions. The DC signal curves generated by friction at different oscillation frequencies of the present invention can be used to construct a correlation model with the operating state of the spherical plain bearing 100, and then used for condition monitoring of the spherical plain bearing 100.

[0066] In some embodiments, the spherical bearing 100 includes a first terminal and a second terminal, the first terminal being electrically connected to the outer ring 1 and the second terminal being electrically connected to the inner ring 2, and the first terminal and the second terminal being used to output a DC signal.

[0067] The self-lubricating pad 3, after being modified with graphene, becomes conductive. The wear-resistant coating 4 of the inner ring 2 has semiconductor properties. In this embodiment, the graphene-modified self-lubricating pad 3 has a certain degree of conductivity, but its work function differs significantly from that of a metal, so it cannot be used as the direction of the voltage for metal analysis. When the outer ring 1 and inner ring 2 rotate relative to each other, according to the triboelectric effect, the self-lubricating pad 3 and the wear-resistant coating 4 rub against each other. The voltage direction should be determined by the difference in work functions between the graphene-modified pad and the wear-resistant coating 4. In this embodiment, when the wear-resistant coating 4 is analyzed using a diamond-like carbon coating, the direction of the output voltage can be from the graphene-modified self-lubricating pad 3 (with a higher work function) to the wear-resistant coating 4 (with a lower work function). The first and second terminals are used to output DC signals.

[0068] The condition monitoring method for a spherical plain bearing 100 based on the friction volt effect according to embodiments of the present invention is used to monitor the condition of the spherical plain bearing 100 in any of the above embodiments. The condition monitoring method includes: S1. Obtain the DC signal generated by the triboelectric effect during the relative motion of the inner ring 2 and outer ring 1 in the spherical bearing 100. The characteristic parameters of the DC signal include at least one of the following: peak voltage, charge transfer amount, and signal fluctuation coefficient.

[0069] S2. Based on the DC signal, construct a correlation model between the characteristic parameters in the DC signal and the operating state of the spherical plain bearing 100. The operating state of the spherical plain bearing 100 includes at least one of the following: bearing wear, lubrication failure degree, and remaining life.

[0070] For example, a correlation model between peak voltage and bearing wear can be constructed, and bearing wear can be monitored in real time based on the peak voltage value.

[0071] For example, a correlation model is constructed based on peak voltage, charge transfer amount and lubrication failure degree, and then the lubrication failure degree of spherical plain bearing 100 is monitored in real time to ensure that spherical plain bearing 100 is in a stable and reliable operating condition.

[0072] S3. Real-time acquisition of the DC signal of the spherical plain bearing 100 under operating conditions, and monitoring of the operating status of the spherical plain bearing 100 based on the correlation model. This embodiment can perform condition monitoring and early fault diagnosis of failure modes such as wear fracture, fatigue crack and fatigue fracture of the spherical plain bearing 100. At the same time, it can also be used in conjunction with indirect parameters such as friction torque and temperature, thereby solving problems such as low signal-to-noise ratio and response lag, and meeting the real-time monitoring needs of important fields such as aerospace, automotive industry, intelligent equipment and water conservancy projects.

[0073] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0077] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A spherical plain bearing, characterized in that, include: An outer ring and an inner ring, the inner ring being disposed inside the outer ring, the outer ring having a first surface facing the inner ring, and the inner ring having a second surface facing the outer ring; A self-lubricating pad, wherein the self-lubricating pad is conductive, and the self-lubricating pad is disposed on one of the first surface and the second surface; A wear-resistant coating having semiconductor properties is disposed on the other of the first surface and the second surface. A self-lubricating pad is in contact with the wear-resistant coating. The inner ring and the outer ring move relative to each other to cause the self-lubricating pad and the wear-resistant coating to rub against each other and output a DC signal.

2. The spherical plain bearing according to claim 1, characterized in that, The self-lubricating pad is a woven composite pad, and the self-lubricating pad is modified to make it conductive.

3. The spherical plain bearing according to claim 2, characterized in that, The modification treatment method for the self-lubricating pad includes: preparing an aqueous conductive solution containing a conductive material, and immersing the self-lubricating pad in the aqueous conductive solution; Remove the self-lubricating pad that has absorbed the aqueous conductive solution and dry it to obtain a self-lubricating pad with conductive properties.

4. The spherical plain bearing according to claim 1, characterized in that, The self-lubricating pad comprises a composite matrix woven from PTFE fibers and Kevlar aramid, or the self-lubricating pad comprises a composite matrix woven from PTFE fibers and Nomex aramid.

5. The spherical plain bearing according to claim 1, characterized in that, The self-lubricating pad is disposed on the first surface, and the wear-resistant coating is disposed on the second surface.

6. The spherical plain bearing according to claim 5, characterized in that, The self-lubricating pad is adhered to the first surface by an adhesive that is conductive.

7. The spherical plain bearing according to claim 6, characterized in that, The adhesive comprises a mixed binder and a conductive material.

8. The spherical plain bearing according to claim 5, characterized in that, The wear-resistant coating is formed on the second surface by a surface deposition process; and / or, the wear-resistant coating includes a diamond-like carbon coating or a molybdenum disulfide coating.

9. The spherical plain bearing according to claim 1, characterized in that, Using the outer ring or the inner ring as a substrate, and the first surface of the outer ring or the second surface of the inner ring as a base, the wear-resistant coating is prepared by physical vapor deposition. The preparation process of the wear-resistant coating includes: The substrate is placed in a physical vapor deposition apparatus; A transition layer is sputtered onto the substrate of the substrate; Argon and acetylene gases are introduced into the physical vapor deposition apparatus, with argon as the sputtering medium and acetylene as the carbon and hydrogen sources, to deposit a hydrogenated amorphous carbon coating with semiconductor properties on the surface of the substrate.

10. The spherical plain bearing according to claim 9, characterized in that, The transition layer is a chromium layer; And / or, the thickness of the transition layer is 0.6 micrometers to 1.5 micrometers; And / or, the thickness of the hydrogenated amorphous carbon coating is 2 micrometers to 4 micrometers.

11. The spherical plain bearing according to any one of claims 1 to 10, characterized in that, The inner ring can swing or rotate relative to the outer ring about at least one of a first direction, a second direction, and a third direction, and there is a preset angle between each pair of the first direction, the second direction, and the third direction; And / or, the spherical bearing includes a first terminal and a second terminal, the first terminal being electrically connected to the outer ring and the second terminal being electrically connected to the inner ring, the first terminal and the second terminal being used to output the DC signal.

12. A method for monitoring the condition of spherical bearings based on the triboelectric effect, characterized in that, A condition monitoring method for the spherical bearing according to any one of claims 1 to 11, the condition monitoring method comprising: Acquire the DC signal generated under the triboelectric effect when the inner and outer rings of the spherical bearing move relative to each other; Based on the DC signal, a correlation model is constructed between the characteristic parameters in the DC signal and the operating state of the spherical bearing; The DC signal of the spherical plain bearing under operating conditions is acquired in real time, and the operating status of the spherical plain bearing is monitored based on the correlation model.

13. The method for monitoring the condition of spherical bearings based on the triboelectric effect according to claim 12, characterized in that, The characteristic parameters of the DC signal include at least one of peak voltage, charge transfer amount, and signal fluctuation coefficient. And / or, the operating condition of the spherical bearing includes at least one of bearing wear, lubrication failure, and remaining life.

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