Intelligent metal-polymer plain bearing and method for monitoring the same

Abstract

The present application relates to the technical field of sliding bearing, and especially relates to an intelligent metal polymer sliding bearing and a monitoring method thereof. The sliding bearing comprises an outer ring steel back, a polymer layer and a steel shaft. The polymer layer is fixed to the inner surface of the outer ring steel back. The steel shaft is sleeved in the polymer layer and can rotate relatively. A silk screen printing electrode is arranged between the outer ring steel back and the polymer layer. A plurality of silk screen printing electrodes are arranged at intervals around the polymer layer. The outer surface of the steel shaft is provided with a Si-DLC coating. A plurality of Si-DLC coatings are arranged at intervals around the circumference of the steel shaft. The silk screen printing electrode and the Si-DLC coating constitute a sliding friction nanogenerator. The silk screen printing electrode is integrated in the inner surface of the polymer layer, and the Si-DLC coating is plated on the surface of the steel shaft. Both are integrated in situ, and it is not necessary to open an installation groove or change the material system of the bearing body. The original high load capacity and high wear resistance of the metal polymer bearing are retained.

Description

Technical Field

[0001] This invention relates to the field of sliding bearing technology, and in particular to an intelligent metal polymer sliding bearing and its monitoring method. Background Technology

[0002] Metal polymer plain bearings (MPPBs) consist of an outer steel backing, a polymer layer, and a metal steel shaft. They possess excellent wear resistance, embeddability, self-lubrication, and damping properties, and are widely used in various industrial transmission equipment. However, the polymer layer has extremely low thermal conductivity. Traditional methods of judging lubrication status based on temperature are slow to respond and have poor sensitivity, failing to identify early lubrication deficiencies and easily leading to safety accidents such as bearing burnout and equipment downtime.

[0003] Triboelectric nanogenerators (TENGs) can convert mechanical energy into electrical signals, providing a new approach for self-sensing of bearing conditions. However, existing technologies for applying TENGs to sliding bearings generally suffer from the following shortcomings: Some solutions require creating mounting grooves or embedding functional rings on the bearing body, which disrupts the bearing's material system and makes it difficult to apply to heavy-load conditions of polymer sliding bearings. In addition, existing solutions mostly focus on monitoring a single parameter and cannot simultaneously achieve dual monitoring of rotational speed and lubrication status in the same structure. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the aforementioned background technology by providing an intelligent metal polymer bearing and its monitoring method.

[0005] To achieve the above objectives, the present invention provides an intelligent metal polymer sliding bearing, comprising an outer steel backing, a polymer layer, and a steel shaft, wherein the polymer layer is fixed to the inner surface of the outer steel backing, and the steel shaft is sleeved in the polymer layer and is rotatable relative to it. A screen-printed electrode is disposed between the outer steel back and the polymer layer, and multiple screen-printed electrodes are arranged at intervals around the polymer layer. The screen-printed electrodes are provided with wires. A Si-DLC coating is disposed on the outer surface of the steel shaft, and multiple Si-DLC coatings are arranged at intervals around the circumference of the steel shaft. The screen-printed electrode and the Si-DLC coating constitute a sliding triboelectric nanogenerator. During the rotation of the steel shaft, the polymer layer rubs against the Si-DLC coating. The Si-DLC coating periodically approaches and moves away from the screen-printed electrode, inducing an electrical signal in the screen-printed electrode. The steel shaft speed and lubrication status are obtained by processing the electrical signal.

[0006] Preferably, the line width of the screen printing electrode is between 0.1 and 0.5 mm, and the mesh count of the screen printing electrode is between 5 and 35 mesh.

[0007] Preferably, the four screen-printed electrodes are evenly distributed along the circumference of the polymer layer.

[0008] Preferably, the screen-printed electrode is printed on the polymer layer facing the back of the outer ring steel and is bonded to the back of the outer ring steel.

[0009] Preferably, the Si-DLC coating is deposited on the surface of the steel shaft using physical vapor deposition.

[0010] Preferably, the two Si-DLC coatings are evenly distributed along the circumference of the steel axis.

[0011] Preferably, the device further includes a signal processing unit, which is electrically connected to the screen-printed electrode via a wire. The signal processing unit performs Fourier transform on the electrical signal to obtain the rotational speed and outputs a lubrication status judgment result based on the amplitude change of the electrical signal.

[0012] The present invention also provides a monitoring method for the above-mentioned intelligent metal polymer sliding bearing, comprising the following steps: A wire is led out from the screen printing electrode, and the electrical signal output by the screen printing electrode is collected in real time during the rotation of the steel shaft; Perform a Fourier transform on the electrical signal and calculate the actual rotational speed of the steel shaft based on the signal's characteristic frequencies; The amplitude of the electrical signal is monitored in real time. When the amplitude exceeds the preset threshold, it is determined that there is insufficient lubrication or dry friction, and an early warning message is output.

[0013] Preferably, the electrical signal is a periodic pulse current signal, and the Fourier transform yields the pulse frequency corresponding to one rotation cycle, which is then used to calculate the rotational speed.

[0014] The above-described solution of the present invention has the following beneficial effects: This invention integrates screen-printed electrodes onto the inner surface of a polymer layer and coats the steel shaft surface with a Si-DLC coating, both in-situ integrations that eliminate the need for mounting slots or alterations to the bearing's material system, thus fully preserving the original high load-bearing and high wear-resistance properties of the metal-polymer bearing. Based on the TENG principle, the sensing unit requires no external power supply, and a single sensing structure simultaneously outputs speed and lubrication status signals, overcoming the shortcomings of lag in temperature monitoring and limited functionality.

[0015] Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the sliding bearing of the present invention; Figure 2 This is a schematic cross-sectional view of the sliding bearing of the present invention; Figure 3 This is an exploded structural diagram of the sliding bearing of the present invention; Figure 4 This is a schematic diagram showing the arrangement of the screen-printed electrodes of the present invention; Figure 5 This is a dynamic response curve of the open-circuit voltage of screen-printed electrodes with different mesh numbers at a frequency of 2 Hz according to the present invention. Figure 6 This is a bar chart showing the average open-circuit voltage of screen-printed electrodes with different mesh numbers at a frequency of 2 Hz according to the present invention. Figure 7 This is a dynamic response curve of open-circuit voltage for screen-printed electrodes with different linewidths at a frequency of 2 Hz according to the present invention. Figure 8 This is a bar chart showing the average open-circuit voltage of screen-printed electrodes with different linewidths at a frequency of 2 Hz according to the present invention. Figure 9 The diagram shows the short-circuit current dynamic response curves of screen-printed electrodes with different mesh numbers at a frequency of 2 Hz according to the present invention. Figure 10 This is a comparison chart of the average short-circuit current of screen-printed electrodes with different mesh numbers at a frequency of 2 Hz according to the present invention. Figure 11 The diagram shows the short-circuit current dynamic response curves of screen-printed electrodes with different linewidths at a frequency of 2 Hz according to the present invention. Figure 12 This is a comparison chart of the average short-circuit current of screen-printed electrodes with different linewidths at a frequency of 2 Hz according to the present invention. Figure 13 This is a graph showing the mechanical peeling force-time curves after the screen-printed electrodes of the present invention are pasted under different mesh numbers; Figure 14 This is a bar graph showing the average mechanical peeling force after the screen-printed electrode mesh is pasted under different mesh numbers according to the present invention. Figure 15 This is a graph showing the mechanical peeling force-time curves after the screen-printed electrodes of the present invention are pasted under different line widths; Figure 16 This is a bar chart showing the average mechanical peeling force after screen-printed electrodes are pasted under different line widths according to the present invention. Figure 17 This is a dynamic response curve of the short-circuit current under different mechanical rotation frequencies according to the present invention; Figure 18 This is a bar chart showing the average short-circuit current at different mechanical rotation frequencies according to the present invention. Figure 19 The frequency domain analysis spectra of the current signals at different rotation frequencies are shown in the present invention. Figure 20 This is a dynamic response curve of the short-circuit current under dry friction / oil lubrication conditions according to the present invention; Figure 21 This is a bar chart comparing the average short-circuit current under dry friction / oil lubrication conditions according to the present invention. Figure 22 This is a bar chart showing the average force exerted on the polymer layer and the outer steel backing under different surface pretreatment methods according to the present invention. Figure 23 This is a force-displacement curve of the polymer layer and the outer steel backing bonded under different surface pretreatment methods according to the present invention; Figure 24 This is a schematic diagram of the water contact angle of the untreated sample of this invention; Figure 25 This is a schematic diagram of the water contact angle of the sample subjected to the calcination treatment according to the present invention; Figure 26 This is a schematic diagram of the water contact angle of the sandpaper-treated sample according to the present invention; Figure 27 This is a schematic diagram of the water contact angle of the ultraviolet light-treated sample of the present invention.

[0017] [Explanation of Labels in the Attached Image] 1. Outer ring steel back; 2. Polymer layer; 3. Steel shaft; 4. Screen-printed electrode; 5. Si-DLC coating. Detailed Implementation

[0018] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention and for simplifying the description, and do not 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1 like Figures 1 to 4 As shown, this embodiment provides an intelligent metal polymer sliding bearing, including an outer ring steel back 1, a polymer layer 2, a steel shaft 3, a screen-printed electrode 4, and a silicon-doped diamond-like carbon (Si-DLC) coating. The polymer layer 2 is fixed to the inner surface of the outer ring steel back 1, and the steel shaft 3 is sleeved in the polymer layer 2 and can rotate relative to it. The screen-printed electrode 4 is disposed between the outer ring steel back 1 and the polymer layer 2, and multiple screen-printed electrodes 4 are arranged circumferentially around the polymer layer 2. The Si-DLC coating 5 is disposed on the outer surface of the steel shaft 3, and multiple Si-DLC coatings 5 ​​are arranged circumferentially around the steel shaft 3. The polymer layer 2, the screen-printed electrode 4, and the Si-DLC coating 5 together constitute a sliding triboelectric nanogenerator. When the steel shaft 3 rotates, the Si-DLC coating 5 and the polymer layer 2 make frictional contact. Due to the coupling of triboelectric charging and electrostatic induction, the Si-DLC coating 5 and the screen-printed electrode 4 periodically approach and move away, inducing an electrical signal in the screen-printed electrode 4 to realize speed detection and lubrication status monitoring.

[0022] In this application, the outer steel backing 1 is a cylindrical metal component. Specifically, as shown... Figures 1 to 3 As shown, the outer ring steel back 1 is made of low-carbon steel or stainless steel, providing structural support and high load-bearing capacity for the bearing. The inner surface of the outer ring steel back 1 is sandblasted, with a surface roughness controlled at 1.5-2.5 micrometers to improve the bonding strength of subsequent bonding processes. The polymer layer 2, made of polyoxymethylene, is fixed to the inner surface of the outer ring steel back 1. The polymer layer 2 facing the steel shaft 3 is polished, with a surface roughness controlled at 1.5-2.5 micrometers. The steel shaft 3 is fitted into the polymer layer 2 with a clearance fit, allowing the steel shaft 3 to rotate freely relative to the polymer layer 2.

[0023] In this application, as Figure 2 and Figure 3 As shown, the screen-printed electrode 4 is printed on the polymer layer 2 facing the outer ring steel back 1, and the screen-printed electrode 4 uses conductive silver paste as the printing material.

[0024] Furthermore, the screen-printed electrodes 4 are in the form of a grid, and there are insulating gaps between adjacent screen-printed electrodes 4. In this embodiment, the number of screen-printed electrodes 4 is preferably four, and the four screen-printed electrodes 4 are evenly distributed to improve the monitoring resolution.

[0025] The Si-DLC coating 5 has high hardness, low coefficient of friction and excellent wear resistance. At the same time, its surface chemical properties enable it to generate a stable and high triboelectric charge density when it comes into contact with the polymer layer 2.

[0026] Furthermore, the number of Si-DLC coatings 5 ​​is preferably two, and the two Si-DLC coatings 5 ​​are evenly spaced apart.

[0027] This application also provides a monitoring method for the above-mentioned intelligent metal polymer sliding bearing, used for speed detection and lubrication monitoring, comprising the following steps: A wire is led out from any of the screen-printed electrodes 4 and connected to an external signal processing unit. As the steel shaft 3 rotates, the Si-DLC coating 5 on its surface periodically approaches and moves away from the screen-printed electrodes 4 within the polymer layer 2.

[0028] In some embodiments of this application, the external signal processing unit can be electrically connected to all screen-printed electrodes 4. This connection method enables dual monitoring of rotational speed and lubrication status, as well as pressure monitoring, achieving triple monitoring.

[0029] Because Si-DLC and polyoxymethylene (POM) occupy different positions in the triboelectric sequence, charge transfer occurs when they are close together. POM tends to lose electrons and become positively charged, while Si-DLC tends to gain electrons and become negatively charged. When they move away from each other, an induced potential is generated on the screen-printed electrode 4 under the action of electrostatic induction, driving electrons to flow in the external circuit and forming a pulsed current / voltage signal.

[0030] The specific preparation steps of the screen-printed electrode 4 are as follows: Step A1, Steel sheet pretreatment: Take the steel sheet for screen printing, sandblast it until the surface roughness is about 2 micrometers, then ultrasonically clean it with anhydrous ethanol for 15 minutes, take it out and blow it dry with nitrogen for later use.

[0031] Step A2, Polymer Layer Pretreatment: Take the polymer layer board and use 400-grit sandpaper to evenly sand the surface to be printed, achieving a surface roughness of approximately 2 micrometers. After sanding, rinse with deionized water, then wipe with anhydrous ethanol and air dry. The purpose of sanding is to improve the adhesion of the silver paste electrode to the polymer surface.

[0032] Step A3, screen printing: ... Figure 4 The electrode pattern shown is made into a screen printing plate, and conductive silver paste is screen printed on the surface of the polymer layer plate after step A2.

[0033] Step A4, Curing: Place the printed polymer layer 2 into an oven and keep it at 50°C for 80 minutes to allow the organic solvent in the conductive silver paste to fully evaporate and the silver powder particles to sinter and solidify, forming a screen-printed electrode 4 with good conductivity. Then, pre-treat the side of the polymer layer 2 with the screen-printed electrode 4 to further enhance the bonding force.

[0034] After the screen-printed electrode 4 is prepared, the polymer layer 2 needs to be bonded to the outer steel backing 1. The specific steps are as follows: Step B1, Adhesive application: After surface treatment on the back side of the polymer layer 2 on which the screen-printed electrode 4 is printed, a structural adhesive with a thickness of about 100 micrometers is uniformly applied.

[0035] Step B2, Rolling and Molding: The polymer layer 2 processed in step B1 is rolled into a cylindrical shape and placed inside the outer steel backing 1, so that the outer surface of the polymer layer 2 is in contact with the inner surface of the outer steel backing 1. The screen-printed electrode 4 faces the central axis.

[0036] Step B3, Hot Press Curing: Place the molded component into a hot press to firmly bond the polymer layer 2 to the outer steel backing 1, thus completing the preparation of the electrode bushing.

[0037] The Si-DLC coating 5 was prepared using a physical vapor deposition process, and the specific steps are as follows: Step C1, Steel Shaft Pretreatment: The machined steel shaft 3 is degreased, cleaned, and dried. Then it is installed in the vacuum chamber of the PVD equipment.

[0038] Step C2, Ion Cleaning: Evacuate to a base vacuum level better than 1x10⁻¹ -4 Pa, argon gas is introduced, and a negative bias voltage is applied to the steel shaft 3 to generate glow discharge to perform argon ion bombardment cleaning on the surface of the steel shaft 3, removing the surface oxide layer and adsorbed impurities.

[0039] Step C3, Transition Layer Deposition: An extremely thin SiC transition layer is first deposited on the surface of the steel shaft 3 using arc ion plating or magnetron sputtering to improve the adhesion between the subsequent DLC coating and the steel substrate.

[0040] Step C4, Si-DLC functional layer deposition: Argon gas and carbon- and silicon-containing gases are introduced as reaction precursors. The gas flow rate ratio is adjusted to control the silicon doping content in the coating, and the total coating thickness is controlled at 1~3 micrometers.

[0041] The specific steps for measuring rotational speed are as follows: Step D1, Signal Acquisition: Acquire the voltage signal output by the screen printing electrode 4 in real time at a sampling frequency of not less than 1 kHz.

[0042] Step D2, Fourier Transform: Perform a Fast Fourier Transform on the acquired time-domain signal to obtain the signal's spectrum. A distinct fundamental frequency peak appears in the spectrum, denoted as f.

[0043] Step D3, Rotational Speed ​​Conversion: For each revolution of the steel shaft 3, the Si-DLC coating 5 and the screen-printed electrode 4 complete two full approach-away cycles. Therefore, one rotational cycle corresponds to two pulse signals, meaning the pulse frequency is equal to twice the rotational frequency. The actual rotational speed n (revolutions per minute) is calculated using the following formula: n=30f For example, if the Fourier transform identifies the fundamental frequency f=50 Hz, then the actual rotational speed n=1500 rpm. Using this method, the rotational speed of the steel shaft 3 can be obtained in real time and accurately.

[0044] Lubrication status is monitored based on changes in the amplitude of the triboelectric signal. The presence or absence of lubricant significantly affects the triboelectric charge density between the Si-DLC coating 5 and the polymer layer 2, such as... Figures 17 to 21 As shown: Under good lubrication conditions: When the bearing is well lubricated, a continuous and stable lubricating oil film forms at the friction interface. This film partially or completely isolates the Si-DLC coating 5 from the polymer layer 2, reducing the actual contact area and contact strength between the two materials. Simultaneously, the presence of the lubricating oil film provides some shielding and dissipation of interfacial charges, thus suppressing the triboelectric charging process. Therefore, the amplitude of the triboelectric signal detected by the screen-printed electrode 4 is significantly reduced, and the overall signal is relatively stable.

[0045] Insufficient Lubrication / Dry Friction State: As the lubricant is gradually consumed, the lubricating film thins or even fails, and the friction interface gradually changes from fluid lubrication to boundary lubrication or dry friction. At this time, the direct contact between the Si-DLC coating 5 and the polymer layer 2 increases, the interfacial electron transfer process is enhanced, and the triboelectric charge density significantly increases. Simultaneously, due to the more intense contact and separation processes, the amplitude of the triboelectric output signal increases significantly. Therefore, the increase in the amplitude of the output voltage or current signal can characterize the deterioration of the lubrication state and insufficient lubricant.

[0046] The specific steps for monitoring lubrication status are as follows: Step E1, Amplitude Extraction: For the voltage signal acquired in real time, calculate the signal amplitude within each pulse period, or calculate the root mean square value of the signal within the sliding time window.

[0047] Step E2, Threshold Judgment: Compare the calculated real-time amplitude with the preset lubrication failure threshold. This threshold is obtained through experimental calibration: record the signal amplitude under known good lubrication conditions as a reference value, and set 140%-200% of the reference value as the warning threshold.

[0048] Step E3, Early Warning Output: When the signal amplitude is detected to be continuously higher than the early warning threshold for a preset time, the signal processing unit determines that there is insufficient lubrication or dry friction, and outputs an early warning signal to the equipment control system to prompt the operator to perform lubrication maintenance, thereby realizing early fault warning.

[0049] The intelligent metal polymer sliding bearing in this embodiment also includes a signal processing unit. The signal processing unit is electrically connected to the screen-printed electrode 4 via a wire and is used to perform Fourier transform on the electrical signal to obtain the rotational speed, and output the lubrication status judgment result based on the amplitude change of the electrical signal.

[0050] Example 2 This embodiment verifies through simulation that the optimal mesh count and line width of the screen printing electrode 4 in Embodiment 1 can achieve better overall performance.

[0051] like Figures 5 to 12 As shown, a control experiment was conducted on the unassembled, flat screen printing electrode 4. Line width and mesh count were used as variables. Four groups were selected for line widths between 0.1 and 0.5 mm (0.1 mm, 0.2 mm, 0.3 mm, and 0.4 mm), and four groups were selected for mesh counts between 5 and 35 (5, 10, 18, and 35 mesh). Triboelectric performance was then compared between these screen printing electrodes 4. The experimental results show that the triboelectric signal increases with increasing mesh count and line width. In summary, the larger the area occupied by the screen printing electrode 4, the greater the output triboelectric signal.

[0052] This embodiment also included an adhesion test on the screen-printed electrode 4, conducted by attaching polyimide tape to the back of the screen-printed electrode 4. A control experiment was performed on screen-printed electrodes 4 with line widths of 0.1mm, 0.2mm, 0.3mm, and 0.4mm, and mesh counts of 5, 10, 18, and 35 meshes. Figure 13 As shown, the peak force is highest at 35 mesh, followed by 10 mesh, and lowest at 18 mesh. All curves exhibit the typical characteristics of an interface separation / peeling process: a rapid rise to the peak, followed by a slow decline and stabilization. Figure 14 As shown, the average force is highest for 10-mesh screens, followed by 5-mesh, and lowest for 18-mesh. This data indicates that the mesh count significantly affects the average force at the interface, with 10-mesh screens exhibiting the strongest bonding / adhesion. Figure 15 As shown, the 0.4mm electrode exhibits the highest peak force, followed by the 0.1mm electrode, while the 0.2mm and 0.3mm electrodes show lower peak forces. The curve shape also follows a rising-peak-decreasing-stabilizing process, reflecting the dynamic changes in interfacial interaction. Figure 16As shown, the average force is highest for the 0.2mm electrode, followed by 0.3mm, and lowest for 0.4mm. The above data indicates that there is an optimal value for electrode width, 0.2mm, at which the average interfacial force is strongest.

[0053] Based on the above two experiments, it was determined that the screen-printed electrode 4, which has a line width of 0.2 mm and a mesh count of 10, can achieve better overall performance.

[0054] Example 3 This embodiment compares different surface pretreatment methods for polymer layer 2 to determine the better surface pretreatment method in step A4 of embodiment 1.

[0055] like Figures 22 to 27 As shown, a comparative experiment was conducted on assembled bearings. Interfacial mechanical property tests of different polymer surface pretreatment methods (Cu, screen printing, calcination, and UV curing) revealed that electrodes prepared by the calcination process exhibited the best interfacial bonding performance, with higher average force and peak force-displacement curves than other processes, demonstrating a gradual, ductile debonding behavior. UV-cured electrodes were second best, with an average force of approximately 2.5 N and moderate interfacial stability. Screen-printed electrodes showed weaker interfacial bonding strength with pure copper electrodes, exhibiting a flat curve and a tendency for early interfacial slippage or brittle peeling. Combined with contact angle test results, calcination and UV treatment significantly reduced the substrate contact angle, effectively improving substrate surface wettability and promoting full contact between the electrode material and the substrate, thereby enhancing interfacial bonding strength. Sandpaper polishing, however, only reduced the contact angle to a limited extent, with limited improvement in interfacial bonding performance. Overall, improved surface wettability is a key factor in enhancing the mechanical reliability of the electrode interface. The calcination process (rapidly burning the electrode surface once with a flame) has a significant advantage in mechanical stability and is more suitable as a pretreatment method for high-reliability devices.

[0056] In some embodiments of this application, plasma treatment of the surface of polymer layer 2 can be used instead of burning, which can also improve the interfacial bonding performance.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A smart metal-polymer sliding bearing, comprising an outer steel backing, a polymer layer, and a steel shaft, wherein the polymer layer is fixed to the inner surface of the outer steel backing, and the steel shaft is sleeved within the polymer layer and is rotatable relative to it, characterized in that: A screen-printed electrode is disposed between the outer steel backing and the polymer layer. Multiple screen-printed electrodes are spaced apart around the polymer layer, and each screen-printed electrode is provided with a conductive wire. The linewidth of the screen-printed electrode is between 0.1 and 0.5 mm, and the mesh count is between 5 and 35 meshes. A Si-DLC coating is disposed on the outer surface of the steel shaft, with multiple Si-DLC coatings spaced apart around the circumference of the steel shaft. The screen-printed electrode and the Si-DLC coating constitute a sliding triboelectric nanogenerator. During the rotation of the steel shaft, the polymer layer rubs against the Si-DLC coating. The Si-DLC coating periodically approaches and moves away from the screen-printed electrode, inducing an electrical signal in the screen-printed electrode. The steel shaft speed and lubrication status are obtained by processing the electrical signal.

2. The intelligent metal polymer sliding bearing according to claim 1, characterized in that, The four screen-printed electrodes are evenly distributed along the circumference of the polymer layer.

3. The intelligent metal polymer sliding bearing according to claim 2, characterized in that, The screen-printed electrode is printed on the polymer layer facing the back of the outer ring steel and is bonded to the back of the outer ring steel.

4. The intelligent metal polymer sliding bearing according to claim 1, characterized in that, The Si-DLC coating is deposited on the surface of the steel shaft using physical vapor deposition.

5. The intelligent metal polymer sliding bearing according to claim 4, characterized in that, The two Si-DLC coatings are evenly distributed along the circumference of the steel axis.

6. The intelligent metal polymer sliding bearing according to claim 1, characterized in that, It also includes a signal processing unit, which is electrically connected to the screen-printed electrode via a wire. The signal processing unit is used to perform Fourier transform on the electrical signal to obtain the rotational speed, and output the lubrication status judgment result based on the amplitude change of the electrical signal.

7. A monitoring method for an intelligent metal polymer sliding bearing according to any one of claims 1-6, characterized in that, Includes the following steps: A wire is led out from the screen printing electrode, and the electrical signal output by the screen printing electrode is collected in real time during the rotation of the steel shaft; Perform a Fourier transform on the electrical signal and calculate the actual rotational speed of the steel shaft based on the signal's characteristic frequencies; The amplitude of the electrical signal is monitored in real time. When the amplitude exceeds the preset threshold, it is determined that there is insufficient lubrication or dry friction, and an early warning message is output.

8. The monitoring method according to claim 7, characterized in that, The electrical signal is a periodic pulse current signal. The Fourier transform yields the pulse frequency corresponding to one rotation cycle, which is then used to calculate the rotational speed.

Images