Graphene temperature and pressure sensing integrated sliding bearing visualization test stand and experimental method

Abstract

This invention avoids damaging the inner integrity of the bearing shell by drilling a hole in it to install a temperature and pressure sensor, and allows for intuitive observation of the details of the oil film and lubricant flow at the contact point between the sliding bearing and the shaft. [Solution] The present invention provides a graphene temperature and pressure sensing integrated sliding bearing visualization test stand and experimental method. The test stand comprises a spindle, a support base and a housing, a drive mechanism connected to one end of the spindle for rotating the spindle, a glass shaft fixed to the other end of the spindle, a test load suspended from the support base and placed inside the housing, a load device for applying pressure to the sliding bearing, a vibrator for applying vibration to the test load, a graphene coating layer applied to the outer surface of the glass shaft for collecting temperature and pressure signals, a camera inserted inside the glass shaft, and a signal transmitter mounted inside the spindle, electrically connected to the graphene coating layer, for transmitting temperature and pressure signals.

Description

Technical Field

[0001] The present invention relates to the technical field of sliding bearing tests, and particularly to a graphene temperature and pressure sensing integrated sliding bearing visualization test bench and an experimental method.

Background Art

[0002] As a core component of rotating machinery, sliding bearings are widely used in important devices such as steam turbines, internal combustion engines, and compressors. Their performance directly affects the reliability, efficiency, and lifespan of mechanical systems. With the development of industrial equipment towards high speed, high load, and intelligent directions, the requirements for sliding bearing tests are becoming increasingly stringent. Since the quality of sliding bearing performance directly relates to the overall performance, reliability, and service life of mechanical devices, it is extremely important to conduct comprehensive and accurate tests on sliding bearings. The current sliding bearing test benches are designed as follows.

[0003] (1) The fan spindle bearing testing machine, publication number CN119437719A, solves the problems of conventional testing structures being complex, test steps being complex, and tests being inaccurate. The technical solution to these problems comprises a platform, a spindle positioned separately on the platform, and a drive assembly that drives the rotation of the spindle. The platform houses a test station located radially along the spindle and for testing the bearing shell of a single sliding bearing. The test station houses a first pressure sensor, a second pressure sensor, and a load unit. The first pressure sensor is used to detect the oil film pressure between the bearing shell of the sliding bearing and the spindle. The load unit is used to drive the bearing shell of the sliding bearing along the radial direction of the spindle to provide a radial load force to the bearing shell of the sliding bearing. The second pressure sensor is used to detect the radial load force provided by the load unit. The testing machine primarily improves test accuracy and simplifies the test structure and test steps. However, this testing machine cannot examine the oil film and lubricant flow conditions at the contact point between the sliding bearing and the shaft.

[0004] (2) The comprehensive performance test stand for tilting pad radial sliding bearings under complex alternating load conditions, as published in CN117091840A, comprises a simulation rotor for simulating the rotor of an actual ship, a drive module connected to one end of the simulation rotor for driving the simulation rotor, two fixed bearing stands each equipped with a tilting pad radial sliding bearing matched to the simulation rotor, a floating bearing stand installed between the two fixed bearing stands, the floating bearing stand being equipped with a load bearing matched to the simulation rotor, and a load module further equipped on the floating bearing stand used to apply complex alternating loads from two directions, vertical and horizontal, to the load bearing in sea conditions, a lubrication module used to provide lubricating oil to the tilting pad radial sliding bearing and the load bearing, and a data acquisition module used to collect test data including performance parameters of the tilting pad radial sliding bearing during the measurement process. This test stand can perform comprehensive performance testing of tilting pad radial sliding bearings under simulated sea conditions. However, this test stand lacks the ability to accurately monitor parameters such as temperature and pressure.

[0005] In summary, conventional sliding bearing test stands have at least the following problems:

[0006] Conventional sliding bearing test stands lack the means to visualize and observe oil films and lubricants.

[0007] Conventional sliding bearing test stands lack the ability to accurately monitor parameters such as temperature and pressure.

[0008] Conventional sliding bearing test stands often require drilling holes in the bearing shell (bearing metal) to install temperature and pressure sensors, which can damage the inner surface of the bearing shell and affect the flow of the lubricating oil film.

[0009] Conventional sliding bearing test stands often require the transmission of measured data via wires, which makes the system overly complex. [Overview of the project]

[0010] In view of this, the present invention provides a visualization test stand and experimental method for a graphene temperature-pressure-sensing integrated sliding bearing in order to solve the problems present in the background art.

[0011] The graphene temperature and pressure sensing integrated sliding bearing visualization test stand of the present invention is The main shaft, support base and housing, A drive mechanism connected to one end of the main spindle and rotating the main spindle, A glass shaft fixed to the other end of the main shaft, A test load unit suspended from the support base and placed inside the housing, A load device for applying pressure to a sliding bearing, A vibrator for applying vibration to the aforementioned test load, A graphene coating layer is applied to the outer surface of the glass shaft for collecting temperature and pressure signals, A camera inserted inside the aforementioned glass shaft, The system includes a signal transmitter mounted within the main shaft, electrically connected to the graphene coating layer, and transmitting temperature and pressure signals.

[0012] Selectively, the drive mechanism includes a motor and a shaft coupling connecting the output shaft of the motor to the main shaft.

[0013] Selectively, the main shaft is supported by rolling bearings.

[0014] Selectively, the loading device includes a pressure handle, a lead screw, and a load block, wherein when the pressure handle is rotated, the lead screw rotates and the load block moves on the test load, applying constant pressure to the sliding bearing.

[0015] Selectively, the camera transmits images of the oil film and lubricant inside the sliding bearing through the glass shaft.

[0016] Selectively, the glass shaft is made of quartz glass, has a cup shape, and is hollow at one end.

[0017] Selectively, the outer surface of the glass shaft is provided with scale-like grooves, and the graphene coating layer is coated within these scale-like grooves.

[0018] Selectively, the signal transmitter transmits the temperature and pressure values ​​obtained in the graphene coating layer to the outside in the form of a wireless signal.

[0019] The experimental method using the graphene temperature and pressure sensing integrated sliding bearing visualization test stand of the present invention is as follows: Step S1 involves mounting a sliding bearing inside a test load and fitting it onto a glass shaft, rotating the main shaft with a drive mechanism, and continuously increasing the rotational speed until a predetermined value is reached. Step S2 involves applying a constant pressure to the sliding bearing using a load device, Step S3 involves starting the vibrator and applying vibration to the sliding bearing, Step S4 involves the camera passing through the glass shaft to capture an image of the oil film and lubricant between the glass shaft and the sliding bearing, The process includes step S5, in which a graphene coating layer detects the temperature and pressure of the oil film, and a signal transmitter transmits the temperature and pressure to the outside in the form of a wireless signal.

[0020] The present invention has the following beneficial effects.

[0021] 1. By installing a camera inside the glass shaft, it is possible to overcome the technical problem that in a conventional test bench, the details of the oil film and the flow of lubricating oil at the contact part between the sliding bearing and the shaft cannot be intuitively observed. This camera can capture the morphological changes of the oil film in real time through a highly transparent glass shaft, clearly display the thickness distribution of the oil film and the turbulent flow state information, and further achieve the technical effect of providing a visualized basis for improving lubrication design. This visualization ability not only helps to deeply understand the oil film formation mechanism but also provides intuitive data support for the optimization of the sliding bearing structure and lubricating oil formulation.

[0022] 2. By applying a graphene coating layer in the micron-level scale-like grooves of the glass shaft, it is possible to overcome the technical problem that in a conventional test bench, drilling holes in the bearing shell to install a temperature-pressure sensor damages the integrity of the inner surface. The graphene coating layer is uniformly coated by the spraying method. By utilizing its excellent thermal conductivity and electrical conductivity, the temperature gradient and pressure distribution at the contact interface can be synchronously monitored in real time, and the frictional resistance between the coating layer and the sliding bearing can be effectively reduced by the biomimetic fish scale structure. Furthermore, this design can avoid the interference caused by the installation of the temperature-pressure sensor on the flow of the oil film and achieve accurate sensing of the temperature and pressure of the sliding bearing.

[0023] 3. By directly connecting the graphene coating layer to a signal transmitter and installing the signal transmitter inside the end connected to the main shaft of the glass shaft and rotating it together with the main shaft, and transmitting the temperature and pressure signals collected by the graphene coating layer to an external receiving device in a wireless manner, it is possible to overcome the technical problem that in a conventional test bench, the wiring due to the rotation of the rotating member is complicated and easily interfered when transmitting data through wires, avoid signal interruption caused by wire damage or poor contact, reduce the maintenance cost, and improve the stability and anti-interference ability of signal transmission in the test process.

[0024] 4. By directly connecting the graphene coating layer to the signal transmitter, technical problems such as the lack of monitoring accuracy of temperature and pressure in the conventional test bench and response delay can be overcome. Due to the high-sensitivity characteristics of the graphene material, pressure changes at the micron level and temperature fluctuations of 0.1 °C can be converted into electrical signals. By such a direct coupling method, the accumulation of errors occurring in the signal adjustment stage of the conventional sensor is avoided, the authenticity and integrity of data are ensured, and the technical effect of providing accurate data support for the performance optimization of the sliding bearing is realized.

Brief Description of Drawings

[0025] [Figure 1] It is a schematic diagram of a graphene temperature and pressure sensing integrated sliding bearing visualization test bench according to an embodiment of the present invention. [Figure 2] It is a schematic diagram of the pattern shape of the graphene coating layer according to an embodiment of the present invention.

Explanation of Reference Signs

[0026] 1 Motor, 2 Shaft coupling, 3 Rolling bearing, 4 Support base, 5 Housing, 6 Test carrier, 7 Loading device, 8 Sliding bearing, 9 Graphene coating layer, 10 Glass shaft, 11 Camera, 12 Vibrator, 13 Spindle, 14 Signal transmitter

Embodiments for Carrying Out the Invention

[0027] Here, the exemplary embodiments illustrated in the drawings will be described in detail.

[0028] Referring to Figures 1 and 2, an embodiment of the present invention provides a graphene temperature-pressure sensing integrated sliding bearing visualization test stand. The visualization test stand comprises a main shaft 13, a support base 4, and a housing 5; a drive mechanism connected to one end of the main shaft 13 for rotating the main shaft 13; a glass shaft 10 fixed to the other end of the main shaft 13; a test load 6 suspended from the support base 4 and positioned inside the housing 5; a load device 7; a vibrator 12 for applying vibration to the test load 6; a graphene coating layer 9 applied to the outer surface of the glass shaft 10 (the surface in contact with the sliding bearing 8) for collecting temperature and pressure (temperature and pressure) signals; a camera 11 inserted inside the glass shaft 10; and a signal transmitter 14 mounted inside the main shaft 13, electrically connected to the graphene coating layer 9, and transmitting temperature and pressure signals. The sliding bearing 8 is mounted inside the test load 6 and fitted onto the glass shaft 10. The load device 7 is used to apply pressure to the sliding bearing 8.

[0029] In one embodiment, the drive mechanism includes a motor 1 and a shaft coupling 2 that connects the output shaft of the motor 1 to the main shaft.

[0030] Specifically, motor 1 is a variable frequency motor that can precisely adjust the output rotational speed and torque according to the actual test requirements. The shaft coupling 2 stably transmits the power of motor 1 to the main shaft 13, ensuring that the main shaft 13 can rotate at a predetermined speed and providing a power base for simulating the operation of the sliding bearing 8 under different working conditions. The use of a variable frequency motor allows for more flexible adjustment of rotational speed during the test process, enabling the simulation of rotational speed changes in various actual operating scenarios, thereby improving the reliability and practicality of the test results.

[0031] In one embodiment, the main shaft may be supported by a rolling bearing 3, which can be a ball bearing or a roller bearing. The rolling bearing effectively reduces friction and vibration during the rotation of the main shaft 13, ensures the rotational accuracy of the main shaft 13, and provides a stable operating environment for testing the sliding bearing 8. The good lubrication and sealing design of the rolling bearing 3 reduces the impact of frictional heat and the intrusion of external impurities on the test results and extends the service life of the rolling bearing 3 itself.

[0032] In one embodiment, the support base 4 is made of aluminum alloy and employs a multi-column frame structure. The spaces between the columns are reinforced with crossbeams and braces to form a spatial truss structure, thereby giving the support base 4 sufficient strength and rigidity to stably support the weight of the test load 6 and its internal equipment. The maximum load capacity can reach 500 kilograms. In addition, a 10 mm thick rubber shock pad is attached to the bottom of the support base 4. Such a shock pad has excellent vibration damping and anti-slip properties and can effectively reduce interference to the test process due to external vibrations, achieving a vibration damping efficiency of 80%, thereby ensuring the accuracy and reliability of the test data.

[0033] In one embodiment, the housing 5 is constructed by casting, ensuring airtightness and structural strength. The surface of the housing 5 is treated with rust prevention, providing good corrosion resistance and durability. The housing 5 is also further designed with vents and a filtration device. The vents employ a louver design, which not only ensures airflow but also prevents the entry of foreign matter from the outside. The filtration device can effectively filter dust particles from the air entering the housing 5, ensuring the cleanliness of the test environment. The housing 5 is also further provided with an observation window. The observation window is made of high-strength transparent organic glass, making it easy for the operator to observe the internal conditions of the housing 5 at any time during the testing process.

[0034] In one embodiment, the loading device 7 includes a pressure handle, a lead screw, and a load block. The lead screw and the support base 4 form a rotational pair, and the pressure handle is fixed to the outer end of the lead screw extending from the support base 4. The load block forms a sliding pair with the test load 6 and a helical pair with the lead screw. When the pressure handle is rotated, the lead screw rotates, and the load block moves on the test load 6, applying a constant pressure to the sliding bearing 8. The lead screw of the loading device 7 ensures a stable output and precise control of pressure during the loading process.

[0035] In one embodiment, as shown in Figure 2, the graphene coating layer 9 is uniformly applied by spraying into the scale-like grooves engraved by a femtosecond laser on the outer surface of the glass shaft 10. Graphene has excellent electrical and thermal properties, allowing it to sense temperature and pressure changes between the glass shaft 10 and the sliding bearing 8 in real time, convert these physical quantities into electrical signals, and acquire temperature and pressure data in real time. This allows for accurate analysis of the operating state of the sliding bearing 8 under various working conditions, provides important data support for studying the friction and wear mechanism of the sliding bearing 8, and avoids drilling holes in the bearing shell to install temperature and pressure sensors, thus avoiding damage to the inner surface of the bearing shell and affecting the flow of the lubricating oil film.

[0036] Specifically, the glass shaft 10 is made of optical glass, which is a quartz material, has a cup shape, and is hollow at one end. The high strength of the optical glass ensures that the glass shaft 10 will not crack or deform when subjected to the pressure and vibration of the sliding bearing 8, and its high transparency helps the camera 11 to clearly observe the flow of the oil film and lubricant between the glass shaft 10 and the sliding bearing 8. The outer surface of the glass shaft 10 is polished to reduce surface roughness, reduce friction with the sliding bearing 8, and at the same time improve the visualization effect of the flow of the oil film and lubricant, contributing to detailed research on the formation, development, and rupture processes of the oil film, as well as the mechanism of action of the oil fluid in the lubrication process.

[0037] Specifically, the outer surface of the glass shaft is precisely engraved with micron-level scale-like grooves using a femtosecond laser processing method. The design of the scale-like grooves mimics the arrangement of fish scales. This structure effectively guides the flow of lubricating oil, reducing flow resistance and simultaneously improving the stability of the oil film. This promotes the formation of the oil film, thereby encouraging uniform distribution of lubricating oil between the glass shaft and the sliding bearing during the operation of the sliding bearing 8, reducing friction and wear and improving the lubrication effect. Furthermore, the presence of the scale-like grooves makes the flow of the lubricating oil film more regular, facilitating observation and analysis of the lubricating oil flow characteristics by the camera 11, and providing a more intuitive and accurate basis for studying the lubrication mechanism of the sliding bearing 8.

[0038] In one embodiment, the camera 11 employs a macro lens and features autofocus and low-light compensation. The autofocus function ensures that even when the distance between the glass shaft 10 and the sliding bearing 8 changes slightly, the camera can still clearly capture details of the oil film and lubricant flow. The low-light compensation function allows the camera 11 to acquire clear images even in dark conditions inside the housing 5. Image data captured by the camera 11 is transmitted in real time to an external data processing device, where the images are analyzed to extract information on oil film thickness and lubricant flow velocity, providing intuitive image evidence for studying the lubrication performance of the sliding bearing 8.

[0039] In one embodiment, the vibrator 12 is an electromagnetic vibrator capable of generating vibrations of different frequencies and amplitudes by adjusting the magnitude and frequency of the input current. The vibration frequency band of the electromagnetic vibrator can cover a variety of vibration frequencies that may be encountered in the actual use of the sliding bearing 8, and it offers high amplitude adjustment accuracy, allowing for accurate simulation of the operating state of the sliding bearing 8 in complex vibration environments.

[0040] In one embodiment, the signal transmitter 14 is mounted inside the end connected to the main shaft 13 of the glass shaft and electrically connected to the graphene coating layer 9. Its operating frequency range covers 2.4GHz to 5.8GHz and can be flexibly adjusted according to the actual test environment and data transmission needs, and it can achieve an effective transmission distance of more than 100 meters, ensuring stable and reliable data transmission even in complex electromagnetic environments. It supports multiple data transmission protocols (i.e., wireless communication protocols) and is compatible with various types of external receiving devices, making it easy for users to select the appropriate data receiving method according to their actual needs. The signal transmitter 14 also has low power consumption characteristics, ensuring data transmission quality while reducing energy consumption, mitigating heat generation problems due to long-term operation, and improving stability and service life. By mounting the signal transmitter 14 inside the end connected to the main shaft 13 of the glass shaft, not only is external space on the test bench saved, but interference to the signal transmitter 14 by the external environment is avoided, further improving the reliability of data transmission.

[0041] Embodiments of the present invention provide an experimental method using a graphene temperature and pressure sensing integrated sliding bearing visualization test stand. Specifically, the method is as follows:

[0042] The sliding bearing 8 is mounted inside the test load 6 and fitted onto the glass shaft 10. When performing the test, the drive mechanism is first turned on. The motor 1 acts as a drive source, outputting stable rotational power which is transmitted to the main shaft 13 via the shaft coupling 2, causing the main shaft 13 to start rotating. The main shaft 13 rotates stably under the support of the rolling bearing 3, which effectively reduces friction and vibration during rotation, ensuring the rotational accuracy of the main shaft 13 and providing a stable operating base for the subsequent test of the sliding bearing 8.

[0043] The rotational speed of the main shaft 13 is continuously increased until a predetermined value is reached, simulating the rotational operation of the sliding bearing 8 in actual operation. After the rotational speed stabilizes, the load device 7 is activated, and the lead screw is rotated by turning the pressure handle. As the lead screw rotates, the load block moves on the test load body 6. The lead screw ensures a stable pressure output during the loading process, and the load block accurately applies a constant pressure to the sliding bearing 8, simulating the operation of the sliding bearing 8 under different load conditions.

[0044] Next, by activating the exciter 12 and adjusting the magnitude and frequency of the input current, the electromagnetic exciter can generate vibrations of different frequencies and amplitudes and transmit them to the sliding bearing 8, providing a reliable means to simulate the operating state of the sliding bearing 8 in a complex vibration environment and to study its performance under those vibration conditions.

[0045] During operation of the sliding bearing 8, a camera 11 mounted inside the glass shaft 10 captures images. The glass shaft 10 is made of optical glass and its outer surface is polished. Its high transparency allows the camera 11 to clearly observe the flow of the oil film and lubricant between the glass shaft 10 and the sliding bearing 8. The polishing reduces surface roughness, reducing friction with the sliding bearing 8 and improving the visualization effect of the oil flow. The camera 11 is equipped with autofocus and low-light compensation functions. The autofocus function ensures that even when the distance between the glass shaft 10 and the sliding bearing 8 changes slightly, the camera can still clearly capture details of the oil film and lubricant flow. The low-light compensation function allows the camera 11 to acquire clear images even in dark conditions inside the housing 5. The image data captured by the camera 11 is transmitted in real time to an external data processing device, where the images are analyzed and information on oil film thickness and oil flow velocity is extracted.

[0046] Simultaneously, the graphene coating layer 9 applied to the scale-patterned grooves engraved with a femtosecond laser on the glass shaft 10 converts micron-level pressure changes and temperature fluctuations into electrical signals, enabling real-time and accurate sensing of temperature and pressure data under different operating conditions of the sliding bearing 8. The scale-patterned grooves effectively guide the flow of the oil, reducing flow resistance and improving the stability of the oil film. A signal transmitter 14 electrically connected to the graphene coating layer 9 transmits the temperature and pressure signals collected by the graphene coating layer 9 wirelessly to an external receiver. This avoids the structural complexity caused by the rotation of the main shaft 13 and the glass shaft 10 using a wire connection method, prevents signal interruptions due to wire wear or poor contact, and improves the stability and interference resistance of signal transmission during the testing process. By combining the temperature and pressure data acquired by the receiving device with the image data collected by the camera 11, the performance representation of the sliding bearing 8 under different operating conditions can be comprehensively analyzed, providing comprehensive and accurate data support for performance optimization, structural improvement, and lubrication design of the sliding bearing 8.

Claims

1. A graphene temperature and pressure sensing integrated sliding bearing visualization test stand, The main shaft, support base and housing, A drive mechanism connected to one end of the main spindle and rotating the main spindle, A glass shaft fixed to the other end of the main shaft, A test load unit suspended from the support base and placed inside the housing, A load device for applying pressure to a sliding bearing, A vibrator for applying vibration to the aforementioned test load, A graphene coating layer applied to the outer surface of the glass shaft, the graphene coating layer for collecting temperature and pressure signals based on changes in the electrical resistance of the graphene coating layer that occur in response to the temperature and pressure between the glass shaft and the sliding bearing, A camera inserted inside the aforementioned glass shaft, A graphene temperature and pressure sensing integrated sliding bearing visualization test stand is characterized by comprising a signal transmitter mounted inside the main shaft, electrically connected to the graphene coating layer, and transmitting the temperature and pressure signals.

2. The graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to claim 1, characterized in that the drive mechanism includes a motor and a shaft coupling connecting the output shaft of the motor and the main shaft.

3. The graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to claim 1, characterized in that the main shaft is supported by a rolling bearing.

4. The graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to claim 1, wherein the loading device includes a pressure handle, a lead screw, and a load block, and when the pressure handle is rotated, the lead screw rotates and the load block moves on the test load to apply a constant pressure to the sliding bearing.

5. The graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to claim 1, characterized in that the camera passes through the glass shaft to observe images of the oil film and lubricating oil inside the sliding bearing.

6. The graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to claim 1, characterized in that the glass shaft is made of quartz glass, has a cup shape, and one end is hollow.

7. The graphene temperature and pressure sensing integrated sliding bearing visualization test stand according to claim 5, characterized in that the outer surface of the glass shaft is provided with scale-patterned grooves, and the graphene coating layer is coated within the scale-patterned grooves.

8. The graphene temperature and pressure sensing integrated sliding bearing visualization test stand according to claim 1, characterized in that the signal transmitter transmits the temperature and pressure signals obtained from the graphene coating layer to the outside in the form of wireless signals.

9. An experimental method using a graphene temperature-pressure-sensing integrated sliding bearing visualization test stand according to any one of claims 1 to 8, Step S1 involves mounting a sliding bearing inside a test load and fitting it onto a glass shaft, rotating the main shaft with a drive mechanism, and continuously increasing the rotational speed until a predetermined value is reached. Step S2 involves applying a constant pressure to the sliding bearing using a load device, Step S3 involves starting the vibrator and applying vibration to the sliding bearing, Step S4 involves using a camera to capture an image of the oil film and lubricant between the glass shaft and the sliding bearing by passing the image through the glass shaft, An experimental method characterized by including step S5 of acquiring temperature and pressure signals, including temperature and pressure information of the oil film, from a graphene coating layer, and transmitting the temperature and pressure signals to the outside in the form of wireless signals using a signal transmitter.

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