Joint bearing and bearing condition monitoring method based on frictional volt effect

Abstract

This invention discloses a spherical plain bearing and a bearing condition monitoring method based on the triboelectric effect. The spherical plain bearing includes an outer ring, an inner ring, and a self-lubricating gasket. 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 modified to possess semiconductor properties. The self-lubricating gasket is disposed on one of the first and second surfaces. The other surface is in contact with and movable relative to the self-lubricating gasket. The relative movement of the inner and outer rings rubs the self-lubricating gasket and outputs a DC signal. This invention can acquire the DC signal generated by friction of the spherical plain bearing at different oscillation frequencies, thereby reflecting the operating state of the spherical plain bearing and achieving real-time monitoring.

Description

Technical Field

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

[0002] Self-lubricating spherical plain bearings possess characteristics such as impact resistance, corrosion resistance, low friction, high wear resistance, self-maintenance, and long service life. They are widely used in important fields such as aerospace, automotive industry, intelligent equipment, and water conservancy projects. However, failure modes such as wear fracture, fatigue cracking, and fatigue fracture pose serious threats to the safe operation of equipment. Establishing a real-time condition monitoring and early fault diagnosis system has significant engineering value.

[0003] The monitoring methods in related technologies mostly rely on indirect parameters such as friction torque and temperature, which have limitations such as low signal-to-noise ratio and response lag, making it difficult to meet the needs of real-time 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 joint bearing capable of real-time monitoring of its operating status.

[0006] The embodiments of the present invention propose a bearing condition monitoring method 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; The self-lubricating pad is modified to give it semiconductor properties. The self-lubricating pad is disposed on one of the first surface and the second surface. The other of the first surface and the second surface is in contact with the self-lubricating pad and is movable relative to the self-lubricating pad. The inner ring and the outer ring move relative to each other to rub the self-lubricating pad and output a DC signal.

[0009] This invention can acquire the DC signal generated by friction of a spherical bearing at different oscillation frequencies, thereby reflecting the operating status of the spherical bearing and realizing real-time monitoring.

[0010] In some embodiments, the self-lubricating pad is disposed on the first surface, and the self-lubricating pad covers the first surface.

[0011] In some embodiments, the self-lubricating pad is modified with PEDOT material, or the self-lubricating pad is modified with molybdenum disulfide material.

[0012] In some embodiments, the modification treatment method for the self-lubricating gasket includes: Prepare a PEDOT conductive solution and immerse the self-lubricating pad in the PEDOT conductive solution; The self-lubricating pad adsorbed with the PEDOT conductive solution was removed and dried to obtain a self-lubricating pad with semiconductor properties.

[0013] 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.

[0014] In some embodiments, the self-lubricating pad is bonded 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 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.

[0017] In some embodiments, 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.

[0018] The bearing condition monitoring method based on the triboelectric effect of this invention is used to monitor the condition of the spherical plain 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.

[0019] 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

[0020] Figure 1 This is a schematic diagram of a joint bearing according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the outer ring of the spherical bearing according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the inner ring in a spherical bearing according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of friction volt generation using a joint bearing according to an embodiment of the present invention.

[0024] 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.

[0025] Figure 6 This is a voltage output curve at different frequencies when the joint bearing of this invention operates.

[0026] Figure label: 100. Spherical plain bearing; 1. Outer ring; 11. First surface; 2. Inner ring; 21. Second surface; 3. Self-lubricating gasket. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are 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.

[0028] See Figures 1 to 6 The following describes the spherical plain bearing 100 and the bearing condition monitoring method based on the triboelectric effect according to embodiments of the present invention.

[0029] See Figures 1 to 4 As shown, the spherical bearing 100 of this embodiment includes an outer ring 1, an inner ring 2, and a self-lubricating gasket 3. 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.

[0030] The self-lubricating pad 3 is modified to give it semiconductor properties. The self-lubricating pad 3 is disposed on one of the first surface 11 and the second surface 21. The other of the first surface 11 and the second surface 21 is in contact with the self-lubricating pad 3 and is movable relative to the self-lubricating pad 3. The inner ring 2 and the outer ring 1 move relative to each other to rub the self-lubricating pad 3 and output a DC signal.

[0031] Based on the triboelectric effect, a direct current signal is generated by the mutual friction between the modified self-lubricating gasket 3 with semiconductor properties bonded to the inner surface of the outer ring 1 of the spherical plain bearing 100 and the outer surface of the inner ring 2. This electrical signal generated by the relative movement and friction between the inner ring 2 and the outer ring 1 of the bearing has a strong coupling relationship with the motion state of the bearing. Therefore, it can provide a more direct and effective means for condition monitoring and fault diagnosis of the spherical plain bearing 100.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] See Figure 2 and Figure 4 In some embodiments, the self-lubricating pad 3 is disposed on the first surface 11 and fixed on the inner surface of the outer ring 1. The self-lubricating pad 3 covers the first surface 11. The self-lubricating pad 3 and the first surface 11 can be the same size and completely fit and are fixed together. Thus, when the inner ring 2 moves relative to the outer ring 1, it can effectively fit and contact the self-lubricating pad 3.

[0036] See Figure 5 In some embodiments, the self-lubricating pad 3 is modified with PEDOT material to give it semiconductor properties. Alternatively, the self-lubricating pad 3 is modified with molybdenum disulfide material to give it semiconductor properties. Of course, the self-lubricating pad 3 can also be modified with other semiconductor materials to give it semiconductor properties.

[0037] See Figure 5 Furthermore, the modification treatment method for the self-lubricating gasket 3 includes: Prepare a PEDOT conductive solution and immerse the self-lubricating pad 3 in it. The PEDOT conductive solution can fully penetrate the self-lubricating pad 3; the immersion time can be 5 to 15 minutes to ensure that the PEDOT conductive solution fully wets the self-lubricating pad 3. PEDOT material is a conductive polymer polymerized from 3,4-ethylenedioxythiophene monomers, and the PEDOT conductive solution mainly contains PEDOT material. During the immersion process, the PEDOT material can be more fully dispersed within the self-lubricating pad 3.

[0038] Remove the self-lubricating pad 3 that has absorbed the PEDOT 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 is between 40 minutes and 80 minutes, thus obtaining a self-lubricating pad 3 with semiconductor properties.

[0039] Since PEDOT is a P-type semiconductor, according to the triboelectric effect, when the P-type semiconductor rubs against the metal, electrons are drawn out from the metal (inner ring 2). After the external circuit is connected, the current flows from the P-type semiconductor (outer ring 1, which is bonded with a PEDOT-modified self-lubricating pad 3) to the metal (inner ring 2).

[0040] 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, which has a continuous lubrication function. It also possesses semiconductor properties after modification.

[0041] The self-lubricating gasket 3 can also be made of other materials with continuous lubrication function and further modified.

[0042] In some embodiments, the self-lubricating pad 3 is bonded to the first surface 11 by an adhesive that is conductive. In this embodiment, the self-lubricating pad 3 is bonded to the inner surface of the outer ring 1 by an adhesive that is conductive, thereby ensuring a stable output of the DC signal.

[0043] See Figure 5Furthermore, 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 outer ring 1, ensuring the reliability of the monitoring data and the stability of the overall connection.

[0044] 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.

[0045] 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.

[0046] In this embodiment of the spherical 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 pad 3 made of fiber and aramid braid, which has undergone PEDOT modification treatment. The modified self-lubricating pad 3 possesses certain semiconductor properties. The self-lubricating pad 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 pad. A certain mass fraction of graphene powder is doped into the adhesive, giving it certain electrical conductivity.

[0047] 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.

[0048] 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.

[0049] See Figure 1Optionally, the first direction is parallel to the axial direction 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. The DC signal generated by the friction of the spherical bearing of the present invention at different oscillation frequencies is as follows: Figure 6 As shown.

[0050] 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.

[0051] In some embodiments, the spherical bearing 100 includes a first terminal and a second terminal. The first terminal is electrically connected to the outer ring 1, and the second terminal is electrically connected to the inner ring 2. The first and second terminals are used to output DC signals. The self-lubricating gasket 3 is treated with PEDOT modification. When the outer ring 1 and the inner ring 2 rotate relative to each other, since PEDOT is a P-type semiconductor, according to the triboelectric effect, when the P-type semiconductor rubs against the metal, electrons are conducted from the metal (inner ring 2). After the external circuit is connected, the current flows from the P-type semiconductor (outer ring 1 with the PEDOT-modified self-lubricating gasket 3 bonded to it) to the metal (inner ring 2). The first and second terminals are used to output DC signals.

[0052] The spherical bearings of this invention also possess characteristics such as impact resistance, corrosion resistance, low friction, high wear resistance, self-maintenance, and long service life.

[0053] The bearing condition monitoring method based on the triboelectric effect of this invention is used to monitor the condition of a spherical plain bearing 100 according to 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] S3. Real-time acquisition of DC electrical signals 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.

[0058] This embodiment can perform condition monitoring and early fault diagnosis of failure modes such as wear fracture, fatigue crack and fatigue fracture of spherical 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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; The self-lubricating pad is modified to give it semiconductor properties. The self-lubricating pad is disposed on one of the first surface and the second surface. The other of the first surface and the second surface is in contact with the self-lubricating pad and is movable relative to the self-lubricating pad. The inner ring and the outer ring move relative to each other to rub the self-lubricating pad and output a DC signal.

2. The spherical plain bearing according to claim 1, characterized in that, The self-lubricating pad is disposed on the first surface and covers the first surface.

3. The spherical plain bearing according to claim 1, characterized in that, The self-lubricating pad is modified with PEDOT material, or the self-lubricating pad is modified with molybdenum disulfide material.

4. The spherical plain bearing according to claim 1, characterized in that, The modification treatment method for the self-lubricating gasket includes: Prepare a PEDOT conductive solution and immerse the self-lubricating pad in the PEDOT conductive solution; The self-lubricating pad adsorbed with the PEDOT conductive solution was removed and dried to obtain a self-lubricating pad with semiconductor properties.

5. 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.

6. The spherical plain bearing according to any one of claims 1 to 5, characterized in that, The self-lubricating pad is bonded 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 any one of claims 1 to 5, 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.

9. A bearing condition monitoring method based on the triboelectric effect, characterized in that, A condition monitoring method for the spherical bearing according to any one of claims 1 to 8, 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.

10. The bearing condition monitoring method based on the triboelectric effect according to claim 9, 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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