A method suitable for testing the lubricating performance of oil in a complex gas environment

Abstract

This invention discloses a method for testing the lubrication performance of engine oil under complex gas environments. The method includes: determining test parameters; constructing a controlled gas environment friction test platform, which provides both engine oil lubrication and a complex gas environment to simultaneously induce friction between two test specimens; clamping the two test specimens onto the controlled gas environment friction test platform; controlling the platform according to the test parameters to conduct friction tests on the two test specimens under engine oil lubrication conditions in a complex gas environment; and analyzing the lubrication performance of the engine oil based on the friction coefficient measured by the controlled gas environment friction test platform. This method can simulate and control different gas environments at a relatively low cost, and can promptly reflect various parameters of the gas environment, making it applicable to most friction and wear testing machines.

Description

Technical Field

[0001] This invention belongs to the field of tribology, specifically relating to a method for testing the lubrication performance of engine oil in complex gas environments. Background Technology

[0002] To conduct in-depth research on the tribological properties of key components of mechanical equipment, it is necessary to systematically investigate the influence mechanisms of different operating environments on the frictional behavior of parts. Among these, the gas environment, as a key variable, has a significant impact on frictional performance. By precisely controlling parameters of the gas environment, such as composition, pressure, and humidity, the frictional response laws of components under specific gas environments can be effectively revealed, thus providing a theoretical basis for optimizing lubrication design and adapting to operating conditions.

[0003] In tribological research, testing methods for lubricating oil performance under specific gas environments are crucial. By employing inert gases (such as nitrogen and argon) or reactive atmospheres (such as oxygen, nitric oxide, and hydrogen), the effects of environmental factors on material surface protection, oxidation, and corrosion can be accurately simulated. This allows for the simulation of actual working conditions in metal friction pair experiments, ensuring high reliability in comparing the tribological properties of different oil samples. This method, through precise control of key parameters such as gas composition, pressure, and humidity, can not only evaluate the differences in anti-wear properties, extreme pressure properties, and lubricating film stability of base oils and additives under inert, oxidizing, or extreme environments, but also reveal the synergistic mechanism of oil sample-environment interaction. For example, in the nuclear energy field, tribological performance studies of NBG-18 nuclear graphite surface polymer-like carbon coatings under nitrogen environments have been conducted; in the aerospace and electrified railway industries, research on current-carrying friction pairs under different service environments has been carried out, with a focus on summarizing the current-carrying tribological performance and dynamic evolution behavior of electric arcs under environmental conditions such as humidity, temperature, gas environment, crosswind, and air pressure; and in the deep space exploration strategy, efforts are being made to develop heavy-load superlubricating technology in special environments such as CO2 atmospheres. This controlled tribological system testing not only provides key data support for oil selection, operating condition adaptation, and lubrication formula optimization for industrial equipment, but also promotes the targeted development of high-performance lubricating materials, possessing significant engineering application value.

[0004] In friction experiments, the design of test methods for the lubrication performance of engine oil under different gas environments must be closely integrated with the actual operating conditions. Precise control and measurement of gas parameters are crucial to ensuring the validity of the experiment. Therefore, the core of evaluating the quality of an oil performance test method lies in its ability to regulate the gas environment and its monitoring accuracy.

[0005] Existing methods for testing the lubrication performance of engine oil in a gaseous environment mainly include the following two:

[0006] One method is the gas-liquid two-phase simulation test, which uses a micro-nano bubble generator to break specific gases (such as nitrogen oxides and sulfur oxides) into micro-nano-scale bubbles, injects them into lubricating oil to form a gas-liquid two-phase mixture system, and simulates the state of gas-containing lubricating oil under actual operating conditions such as those of an engine. Combined with a temperature and humidity controllable gas environment chamber, the friction coefficient, wear amount, and bubble distribution are monitored in real time.

[0007] Another method is the controlled gas environment friction test, which involves filling a closed environment chamber with a single or mixed gas, driving the friction pair with a servo motor, and automatically recording the friction coefficient to evaluate the effect of the gas on the stability of the lubricating film.

[0008] Currently, while simulation methods widely used in lubricant performance testing play an important role, they still have several limitations: First, existing methods are mostly limited to simulating a single gas phase environment, failing to fully consider the complex interaction mechanisms between the gas and liquid phases in actual working conditions; second, the manufacturing cost of equipment such as micro-nano bubble generators and multi-channel gas mixing systems required for gas-liquid two-phase simulation is significantly higher than that of conventional friction and wear testing machines, which to some extent limits their widespread application; in addition, existing testing systems generally suffer from a single simulation mode, making it difficult to simulate differentiated environments for different friction modes such as point contact friction, linear friction, and reciprocating friction, and lacking reproducibility on different types of friction and wear testing machines. These factors all restrict the accuracy and universality of the test results. Summary of the Invention

[0009] To address the problems existing in the prior art, this invention provides a method for testing the lubrication performance of engine oil in complex gas environments. This method can simulate and control different gas environments at a low cost, and can reflect various parameters of the gas environment in a timely manner. It is applicable to most friction and wear testing machines.

[0010] To achieve the above objectives, the present invention adopts the following specific technical solution: A method for testing the lubrication performance of engine oil in complex gas environments, the method comprising the following steps: Step 1: Determine the test parameters and build a controlled gas environment friction test platform. The controlled gas environment friction test platform is used to realize the friction of two test pieces while providing oil lubrication and a complex gas environment. Step 2: Clamp the two specimens onto the controlled gas environment friction test platform; Step 3: Control the controllable gas environment friction test platform according to the test parameters, so that the two specimens can be subjected to friction test under the working condition of oil lubrication in a complex gas environment. Step four: Analyze the lubricating performance of the engine oil based on the friction coefficient measured by the controlled gas environment friction test platform.

[0011] Furthermore, the controllable gas environment friction test platform built in step one includes a friction and wear testing machine, a gas environment chamber, a gas supply system, a lubrication system, and a central control system; The friction and wear testing machine includes a worktable and a transmission component located on top of the worktable; the worktable and the transmission component are respectively used to clamp a specimen to achieve friction between two specimens; The gas environment chamber is sealed and fixedly installed on the workbench to seal the specimen inside, thereby providing the specimen with a complex gas environment and oil lubrication. The gas supply system is used to deliver gas into the engine oil in the gas environment chamber to form a complex gas environment; The lubrication system is used to provide lubricating oil to the friction surfaces of the specimen; The central control system is used to achieve real-time monitoring and precise control of the gas environment inside the gas environment chamber by controlling the gas supply system.

[0012] Furthermore, the gas environment chamber includes a chamber body, a dynamic sealing membrane, an air inlet pipe, a gas mixing pipe, a heating device, a humidification device, a temperature sensor, a humidity sensor, and a gas sensor; The chamber is a cylindrical body with openings at both ends. The bottom end is fixedly installed on the top surface of the workbench, and the top end is sealed with the dynamic sealing film, thereby forming a sealed space between the workbench, the chamber and the dynamic sealing film. The dynamic sealing film is dynamically sealed to the transmission component; The air inlet pipe penetrates the side wall of the cylinder, with one end connected to the air supply system and the other end connected to the mixing pipe located at the bottom of the chamber, for supplying gas into the mixing pipe; The mixing pipe is provided with multiple small holes; The heating device is fixedly installed on the cylinder and is used to heat the engine oil; The humidification device is used to deliver water vapor into the cabin to regulate the humidity level; The temperature sensor is used to detect the engine oil temperature in real time; The humidity sensor is used to detect the humidity inside the cabin in real time; The gas sensor is used to monitor the concentration of a predetermined gas inside the cabin in real time; The central control system is connected to the heating device, the humidification device, the temperature sensor, the humidity sensor, and the gas sensor, and is used to control the heating device, the humidification device, and the gas supply system.

[0013] Furthermore, the gas supply system includes multiple gas cylinders, a pressure reducing valve, a shut-off valve, a check valve, a pressure gauge, and a mass flow controller; Each gas cylinder is used to store a different gas and is connected to the inlet pipe via a pipeline; Each pipeline is sequentially equipped with the pressure reducing valve, the shut-off valve, the check valve, the pressure gauge, and the mass flow controller. The mass flow controller is used to control the mass flow rate of the gas to simulate different gas concentrations; The central control system controls the concentration of various gases through various shut-off valves and mass flow controllers.

[0014] Furthermore, the cabin is also equipped with an exhaust port that can be opened and closed, and an exhaust pipe connected to the exhaust port; The exhaust pipe is equipped with a filter, and the other end of the exhaust pipe extends outdoors.

[0015] Furthermore, the controlled gas environment friction experimental platform also includes a security system to maintain the safety of the experimental environment; The security system includes an exhaust hood, an audible and visual alarm, a gas sensor, and an explosion-proof fan; The exhaust hood is installed on the top of the friction and wear testing machine; The audible and visual alarm, the gas sensor, and the explosion-proof fan are all connected to the central control system.

[0016] Furthermore, the gas environment chamber also includes a pressure sensor installed inside the chamber, which is used to monitor the gas pressure inside the chamber in real time and maintain the gas pressure level inside the chamber through the central control system.

[0017] Furthermore, the dynamic sealing film is made of high-strength rubber.

[0018] Furthermore, the heating device consists of heating elements / heating rods.

[0019] Furthermore, the central control system adopts a PLC measurement and control system.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: 1. The testing method of this invention can achieve the ability to simulate multiple gas mixtures. Through the gas supply system, different gases can be mixed to accurately simulate various gas environment conditions. By adjusting the mixing ratio and type, diverse experimental needs can be met, such as simulating air pollution environments or conditions under specific gas concentrations.

[0021] 2. The testing method of this invention can adjust the type of gas supplied, thus simulating different gas composition environments. This flexibility allows for rapid switching of different experimental conditions within the same apparatus, improving experimental efficiency and flexibility.

[0022] 3. The testing method of this invention enables a thorough gas-liquid mixing mechanism. The design of perforating the mixing tube ensures complete mixing of the gas and liquid. This design effectively improves the uniformity and stability of the gas components and reduces errors caused by uneven mixing during the experiment.

[0023] 4. The testing method of this invention can achieve humidity and temperature regulation through a humidification device and a heating device, enabling precise control of the humidity and temperature of the gas environment. This is especially important for friction experiments that need to be conducted under specific humidity and temperature conditions, ensuring the repeatability and accuracy of the experimental results.

[0024] 5. The testing method of this invention can utilize a PLC (Programmable Logic Controller) measurement and control system to achieve real-time monitoring and precise control of complex gas environments. This real-time monitoring system not only improves the automation level of the testing process but also responds and adjusts environmental parameters in a timely manner, ensuring the stability and safety of the experiment.

[0025] 6. The testing method of this invention has good versatility and adaptability, and can be compatible with the experimental requirements of various gas environments (including single-component, mixed gas, and special atmospheres) and different friction forms (such as point contact, line contact, and surface contact friction). Through the modular design concept of the controlled gas environment friction test platform, this method only requires appropriate parameter adjustments and equipment adaptation to achieve seamless integration with various mainstream friction and wear testing machines, ensuring the portability of the test scheme and the comparability of results on different experimental platforms. Attached Figure Description

[0026] Figure 1 This is a flowchart of the method for testing the lubrication performance of engine oil in complex gas environments according to the present invention; Figure 2 This is a schematic diagram of a controlled gas environment friction experimental platform; Figure 3 This is a schematic diagram of a gas environment chamber; Figure 4 These are 2D / 3D morphology images of a specimen under different oil samples and various gas environments; Figure 5 SEM images of a specimen under different oil samples and various gas environments; Figure 6 XPS elemental analysis of the wear track surface of a specimen after friction tests under different oil and gas environments; Figure 7 This is a schematic diagram of a molecular simulation of the friction process.

[0027] Figure label: 1-Friction and wear testing machine, 2-Gas environment chamber, 3-Gas supply system, 4-Central control system, 5-Security system, 6-Specimen, 11-Transmission component, 21-Chamber body, 22-Dynamic sealing membrane, 23-Inlet pipe, 24-Mixing pipe. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This embodiment provides a method for testing the lubrication performance of engine oil in complex gas environments, such as... Figure 1 As shown, the method includes the following steps: Step one involves determining the test parameters and constructing a controlled gas environment friction test platform. This platform is used to simulate friction between two specimens 6 while providing oil lubrication and a complex gas environment. When determining the test parameters, the actual friction conditions under the required gas environment are used as the background to determine specific parameters such as gas type, concentration, flow rate, friction load, frequency, and time. When constructing the controlled gas environment friction test bench, the experimental platform is systematically designed based on the requirements of simulating the target gas environment and constructing a tribological experimental system. This includes determining the type of test oil, friction type (point contact friction, line contact friction, and surface contact friction, etc.), gas composition and proportion, and integrating it with the required friction and wear testing machine 1. This is the core step. The experimental platform includes the friction and wear testing machine 1, a gas environment chamber 2, a gas supply system 3, a lubrication system, a central control system 4, and a safety system 5.

[0030] Step 2: Clamp the two specimens 6 onto the controlled gas environment friction test platform; Step 3: Control the controllable gas environment friction test platform according to the test parameters, so that the two specimens 6 can be subjected to friction test under the working condition of oil lubrication in a complex gas environment. Step four: Analyze the lubricating performance of the engine oil based on the friction coefficient measured by the controlled gas environment friction test platform.

[0031] The controllable gas environment friction test platform constructed in step one above includes a friction and wear testing machine 1, a gas environment chamber 2, a gas supply system 3, a lubrication system, and a central control system 4; as follows: Figure 2 and Figure 3 As shown.

[0032] The friction and wear testing machine 1 is used to realize friction between two test pieces 6, such as point contact friction, line contact friction, and surface contact friction. The friction and wear testing machine 1 includes a worktable and a transmission component 11 located on top of the worktable. The friction and wear testing machine 1 can detect the friction coefficient of the two test pieces 6 in real time during the friction process. The top surface of the worktable is flat. Fixtures can be fixedly installed at the center of the worktable and the bottom end of the transmission component 11, so that the worktable and the transmission component 11 respectively hold one test piece 6 through the fixtures, and drive one test piece 6 to move relative to the other test piece 6 through the transmission component 11, thereby realizing point contact friction, line contact friction, and surface contact friction.

[0033] The gas environment chamber 2 is sealed and fixedly mounted on the workbench to seal the specimen 6 inside, thereby providing the specimen 6 with a complex gas environment and oil lubrication. The complex gas environment is achieved by a gas supply system 3, which supplies the gas required to create the complex gas environment to the oil inside the gas environment chamber 2. Oil lubrication is achieved by a lubrication system, which provides lubricating oil to the friction surfaces of the specimen 6. The lubrication system can be implemented by an oil pump and oil pipes, with the oil pump located on the outside of the gas environment chamber 2 and the oil pipes extending into the interior of the gas environment chamber 2.

[0034] The central control system 4 is used to achieve real-time monitoring and precise control of the gas environment within the gas environment chamber 2 by controlling the gas supply system 3. The central control system 4 employs a PLC monitoring and control system. By using the PLC monitoring and control system, real-time monitoring and precise control of the gas environment can be achieved. The PLC (Programmable Logic Controller) monitoring and control system not only improves the automation level of the experimental apparatus but also enables immediate response and adjustment of environmental parameters, thereby ensuring the stability and safety of the experimental process. This real-time monitoring system not only makes operation more efficient but also significantly improves the accuracy of experimental data and the controllability of experimental conditions.

[0035] The gas environment chamber 2 includes a chamber body 21, a dynamic sealing membrane 22, an air inlet pipe 23, a mixing pipe 24, a heating device, a humidification device, a temperature sensor, a humidity sensor, a gas sensor, and a pressure sensor. The chamber body 21 is a cylindrical body open at both ends, with its bottom fixedly mounted on the top surface of the workbench and the top sealed with the dynamic sealing membrane 22, thus forming a sealed space between the workbench, the chamber body 21, and the dynamic sealing membrane 22; the chamber body 21 can be a rectangular cylindrical structure. The dynamic sealing membrane 22 dynamically seals against the transmission component 11, which passes through the dynamic sealing membrane 22. The top end of the transmission component 11 is connected to the drive device of the friction and wear testing machine 1, and the bottom end is fitted with a clamp to mount a specimen 6, thereby causing the specimen 6 to move relative to another specimen 6 for friction. The dynamic sealing membrane 22 is made of high-strength rubber. The pressure sensor is installed in the chamber body 21 to monitor the gas pressure inside the chamber body 21 in real time and maintains the gas pressure level inside the chamber body 21 through the central control system 4.

[0036] An intake pipe 23 penetrates the side wall of the cylinder, with one end connected to the air supply system 3 and the other end connected to a mixing pipe 24 located at the bottom of the chamber 21, for supplying gas into the mixing pipe 24. The mixing pipe 24 has multiple small holes, through which various gases are received and mixed. The mixed gas is then discharged through the holes and enters the engine oil at the bottom of the chamber 21 to mix with the oil. A heating device is fixedly installed in the cylinder for heating the engine oil. The heating device can consist of heating elements / heating rods. A humidification device is used to supply water vapor into the chamber 21 to regulate humidity levels; the humidification device can be a humidifier. A temperature sensor is used to detect the engine oil temperature in real time; a humidity sensor is used to detect the humidity inside the chamber 21 in real time; a gas sensor is used to monitor the concentration of a predetermined gas inside the chamber 21 in real time.

[0037] The central control system 4 is connected to the heating device, humidification device, temperature sensor, humidity sensor and gas sensor. The central control system 4 controls the heating device according to the determined test parameters and the oil temperature detected by the temperature sensor, controls the humidification device according to the determined test parameters and the humidity detected by the humidity sensor, and controls the gas supply system 3 according to the determined test parameters and the gas composition and concentration detected by the gas sensor.

[0038] The gas supply system 3 includes multiple gas cylinders, pressure reducing valves, shut-off valves, check valves, pressure gauges, and mass flow controllers. Each gas cylinder stores a type of gas and is connected to an inlet pipe 23 via a pipeline, which delivers the gas stored in the cylinder to the inlet pipe 23. Each gas cylinder has an inlet pipe 23, and multiple inlet pipes 23 are connected to a mixing pipe 24, thus connecting each gas cylinder to the mixing pipe 24 via multiple inlet pipes 23. Each pipeline is sequentially equipped with a pressure reducing valve, shut-off valve, check valve, pressure gauge, and mass flow controller. The pressure reducing valve is used to reduce the pressure of the gas in the cylinder; the shut-off valve is used to control the opening and closing of the pipeline; the check valve is used to ensure that the gas in the pipeline flows only from the gas cylinder towards the inlet pipe 23, preventing gas from flowing from the inlet pipe 23 back to the gas cylinder; the pressure gauge is used to detect the gas pressure in the pipeline; the mass flow controller is used to control the mass flow rate of the gas to simulate different gas concentrations; the central control system 4 controls the concentration of various gases through the shut-off valves and the mass flow controller. To simulate different gas environments, the composition of the gas environment can be changed by replacing the gas cylinder. At the same time, the mass flow rate of the gas can be controlled by mass flow rate to simulate the concentration of different gases. Small holes are made at the injection end to achieve full mixing of gas and liquid.

[0039] The hull 21 is also equipped with an on / off exhaust port and an exhaust pipe connected to the exhaust port; a filter is installed in the exhaust pipe, and the other end of the exhaust pipe extends to the outside. The exhaust port can be opened and closed by an automatic control valve such as a solenoid valve.

[0040] To enhance testing safety, the aforementioned controlled gas environment friction test platform also includes a security system 5 for maintaining a safe experimental environment. Security system 5 includes an exhaust hood, an audible and visual alarm, a gas sensor, and a blower. The exhaust hood is mounted on top of the friction and wear testing machine 1. The audible and visual alarm, gas sensor, and blower are all connected to the central control system 4. The gas sensor, connected to the central control system 4, sends detection signals to the system. The central control system 4 determines whether there is a toxic gas leak based on the gas sensor's detection signal. When a toxic gas leak is detected, it controls the audible and visual alarm to send an alarm signal and activates the blower to vent the indoor gas to the outside. Security system 5 ensures the safety of the experiment by venting toxic gases in the event of a leak.

[0041] The following aspects can be analyzed regarding the friction test of specimen 6: 1. Oil lubrication friction test under multi-component gas environment: Precisely mix gas mixtures (such as NO) according to target operating conditions (e.g., internal combustion engine combustion chamber environment). x / SO xThe N2-O2 ternary system is used to control the partial pressure and flow rate of each component through a mass flow controller, ensuring that the gas concentration error is ≤1.5% to simulate a real gas environment. Different types of friction experiments are performed on a multi-functional friction testing machine, and the friction coefficient and transient fluctuations are collected simultaneously.

[0042] 2. Multi-dimensional Data Analysis of Tribological Behavior: Statistical analysis using multiple sets of friction coefficient data reveals the evolution of tribological behavior under the target gas environment and provides a theoretical basis for subsequent research. A comparative analysis of the obtained friction data from various oil samples is also conducted. In tribological research, the friction coefficient is key to measuring frictional resistance and is crucial for evaluating lubricant performance. It reflects the force between friction pairs and is influenced by material properties and lubricant performance. High-quality lubricants can effectively reduce the friction coefficient and decrease resistance. Measuring the friction coefficient under different conditions using a friction testing machine allows for understanding lubricant performance and provides a basis for formulation optimization. This data is essential for selecting lubricants suitable for different application scenarios and improving equipment efficiency.

[0043] In summary, using data related to the friction coefficient to evaluate and characterize tribological behavior is an intuitive and effective method. Specific indicators can be found in the examples below: First, friction coefficient curves or bar charts with error bars can be used to observe the percentage increase in friction coefficient between different control charts. The coefficient of variation (variance effect) of friction coefficients in different control groups can also be observed to specifically evaluate the quality of friction behavior. When operating condition I changes to operating condition II, the average friction coefficient of oil sample A increases from 0.1118 to 0.1209 (relative increase of 8.1%), and its coefficient of variation (CV) increases from 7.9% to 66.5%. The average friction coefficient of oil sample B increases from 0.1193 to 0.1268 (relative increase of 6.3%), and its coefficient of variation (CV) increases from 8.1% to 42.9%. This preliminarily indicates that oil sample B is more adaptable to the environment of operating condition II than oil sample A.

[0044] 3. In-depth study of the mechanism of gas-surface interaction: A combination of ultra-depth-of-field microscopy and scanning electron microscopy (SEM) was used to analyze the morphology of the wear tracks, and X-ray photoelectron spectroscopy (XPS) was employed to obtain the elemental distribution and chemical valence state evolution of the tribochemical reaction film. Specific examples include... Figure 4 and Figure 5 As shown in the figure, the wear track morphology changes of different oil samples under various operating conditions can be observed from the morphology diagram. Conditions I and II show relatively better wear, while conditions III and IV show more severe wear. The collected wear track depth data can be compared with the bench test data; if the trends are the same, the reliability of the test plan can be verified.

[0045] like Figure 6As shown, XPS color analysis reveals the film-forming effect of various elements in the oil sample under the influence of the gas environment. The figure clearly shows that as the NO gas concentration increases, the content of each element decreases, indicating that NO gas has a negative effect on the boundary film formation of these elements on the friction surface. Similarly, as the EGR gas content increases, the content of each element also decreases.

[0046] Simultaneously, molecular dynamics simulations can be used to study the interaction mechanisms between lubricating oil molecules, additives, and friction pair surfaces at the atomic scale, elucidating the formation and failure mechanisms of boundary films in complex gas environments, such as... Figure 7 As shown.

[0047] The above methods can be used to comprehensively analyze and evaluate the results of friction experiments, revealing the mechanism and underlying principles of the effect of the gas environment on tribological behavior.

[0048] 4. Integration of test results from multi-source data fusion: The obtained multi-source data are summarized and analyzed to comprehensively evaluate the lubrication performance of different oils in complex gas environments.

[0049] This evaluation system conducts an in-depth analysis from three key dimensions: First, the tribological performance dimension, which uses a real-time friction coefficient monitoring system to obtain dynamic friction characteristic curves, combines high-resolution scanning electron microscopy (SEM) to characterize the surface morphology of the wear tracks, and utilizes the three-dimensional morphology stitching function of an optical microscope to accurately quantify the wear volume. The system focuses on examining the stability of the friction coefficient, wear track morphology characteristics, and wear amount under different gas environments. Second, the boundary film stability dimension, which innovatively employs X-ray photoelectron spectroscopy (XPS) for in-depth analysis, systematically studying the chemical state evolution of elements on the wear track surface. Through high-resolution spectral analysis, the system quantitatively characterizes the chemical valence distribution of key elements (such as P and S) in the friction protective film and their transformation laws under hydrogen environmental conditions. Finally, the environmental interference resistance dimension, relying on an environmental simulation experimental device, focuses on analyzing the performance response characteristics of lubricating oil under different gas environment conditions.

[0050] Key evaluation criteria: good stability of the coefficient of friction (variance controlled within 30%); the wear surface shows a small wear depth and no obvious large-area peeling; XPS analysis shows that a rich and uniformly distributed friction protective film has formed on the wear surface.

[0051] The detailed procedure of the friction experiment in a gaseous environment is as follows: Before conducting friction experiments with complex gases, ensuring the accuracy of the simulated gas environment is crucial. First, a detailed study of the required gas composition is necessary. This includes the proportions and concentration ranges of each gas, as well as temperature and humidity conditions that may affect the experimental results. Accurate setting of these parameters is essential for the repeatability and accuracy of the experimental results. Selecting appropriate gas cylinders and specialized gas generators is the first step. Depending on the needs, different types and sizes of gas cylinders may be required to hold different gas compositions. Each cylinder must be equipped with pressure reducing valves, shut-off valves, and other devices to ensure safe control of gas release and flow rate. Furthermore, the parameters of the mass flow controller need to be preset to precisely control the mass flow rate and concentration of the gas according to the experimental design.

[0052] After preparing the gas supply system 3, ensuring its stability and reliability is crucial. First, all components of the monitoring and control system need careful inspection, including the PLC control system, temperature sensors, and heating modules. The PLC (Programmable Logic Controller) control system is responsible for monitoring and adjusting various parameters during the experiment, such as gas pressure, flow rate, and environmental conditions, ensuring the accuracy and safety of the experiment. By executing pre-set programs and logic, the PLC control system can respond promptly to any potential anomalies, thereby protecting the experimental equipment and personnel. Simultaneously, the proper functioning of pressure gauges and gas sensors (concentration meters) is also essential. Pressure gauges monitor the pressure inside the gas cylinders and experimental chamber, ensuring operation within safe limits. Gas sensors (concentration meters) measure and record the concentrations of various gas components, ensuring that the gases used in the experiment meet predetermined parameter requirements. These measuring devices must be calibrated and verified to ensure their accuracy and reliability.

[0053] In addition, checking and testing the exhaust system is equally important. The exhaust system is responsible for effectively removing waste gases and residual gases generated during the experiment, preventing them from interfering with experimental results or adversely affecting the environment. Ensure that the exhaust system's pipes are unobstructed, valves are functioning properly, and that waste gases are effectively discharged as needed.

[0054] After a series of preparatory steps, the test oil sample is added to the gas environment chamber 2, and the top of the gas environment chamber 2 is sealed using a dynamic sealing membrane 22. This step is to ensure the airtightness of the experimental environment. The sealing operation should be carried out carefully to prevent gas leakage or interference from external environmental factors on the experimental results.

[0055] After confirming the overall airtightness of the equipment, gas is injected into the gas environment chamber 2. During this process, the readings of the PLC control system, pressure gauge, and concentration meter must be closely monitored. The PLC control system is responsible for monitoring and adjusting the gas flow rate and pressure to ensure that the experimental conditions meet the preset requirements. The pressure gauge is used to ensure that the gas pressure is within a safe range and to promptly detect any abnormalities. The concentration meter is used to monitor the composition of the gas mixture to ensure that the required gas concentration reaches the expected level. Once the gas reaches the preset concentration and pressure, the gas cylinder is promptly shut off, and preparation for the friction experiment begins. Throughout the experiment, continuous monitoring of the data changes in the monitoring system is essential to ensure the stability of the experiment and the accuracy of the data.

[0056] After the friction experiment, the gas in the gas environment chamber 2 must first be effectively vented through the exhaust hood. The venting process must continue until all gas is completely exhausted to ensure a safe and clean experimental environment. Once it is confirmed that the gas has been completely removed, the dynamic sealing membrane 22 can be opened, and the rubbed part can be removed for inspection. The inspection process requires careful observation of the surface of the rubbed part to assess its frictional damage. This includes checking for possible wear, deformation, or other surface changes, which will provide important information about frictional performance and durability. After removing the rubbed part, further analysis and measurements are required, such as using a microscope to examine microscopic surface features or performing physical property tests. These analyses will help to gain a deeper understanding of the friction experiment results and verify the effectiveness and accuracy of the experimental design.

[0057] The aforementioned testing method enables precise timed and quantitative control of different gases. Equipped with a mass flow controller, it allows for accurate adjustment of the proportions of various gases according to experimental requirements, simulating the required gas environment under various working conditions. By incorporating temperature, pressure, and gas sensors, it can monitor changes in key parameters during the experiment in real time, ensuring the accuracy and reliability of experimental data. Furthermore, it integrates a waste gas emission and treatment device, effectively treating the waste gases generated during the experiment and achieving harmless treatment of the experimental gases, meeting environmental protection requirements.

[0058] The aforementioned testing method exhibits excellent versatility and adaptability, compatible with various gas environments (including single-component, mixed gas, and special atmospheres) and different friction forms (such as point contact, line contact, and surface contact friction). Through a modular design concept, this method requires only appropriate parameter adjustments and equipment adaptation to seamlessly integrate with various mainstream friction and wear testing machines, ensuring the portability of the testing scheme and the comparability of results across different experimental platforms. This flexibility enables the method to meet diverse scientific research needs and engineering application scenarios.

[0059] The aforementioned testing method employs multivariate data analysis technology, enabling multi-dimensional performance evaluation of lubricating oil samples under complex gas environments. By accurately simulating key parameters of actual operating conditions, it ensures a high degree of consistency between experimental conditions and real-world operating environments, thereby obtaining test results with engineering guidance significance. This testing method not only achieves controllable adjustment of experimental environmental parameters but also accurately reflects the performance of lubricating oils in actual complex gas environments, providing reliable data support for oil product research and development and application.

[0060] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0061] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the lubrication performance of engine oil in complex gas environments, characterized in that, Includes the following steps: Step 1: Determine the test parameters and build a controlled gas environment friction test platform. The controlled gas environment friction test platform is used to realize the friction of two test pieces while providing oil lubrication and a complex gas environment. Step 2: Clamp the two specimens onto the controlled gas environment friction test platform; Step 3: Control the controllable gas environment friction test platform according to the test parameters, so that the two specimens can be subjected to friction test under the working condition of oil lubrication in a complex gas environment. Step four: Analyze the lubricating performance of the engine oil based on the friction coefficient measured by the controlled gas environment friction test platform.

2. The method as described in claim 1, characterized in that, The controllable gas environment friction test platform built in step one includes a friction and wear test machine, a gas environment chamber, a gas supply system, a lubrication system, and a central control system; The friction and wear testing machine includes a worktable and a transmission component located on top of the worktable; the worktable and the transmission component are respectively used to clamp a specimen to achieve friction between two specimens; The gas environment chamber is sealed and fixedly installed on the workbench to seal the specimen inside, thereby providing the specimen with a complex gas environment and oil lubrication. The gas supply system is used to deliver gas into the engine oil in the gas environment chamber to form a complex gas environment; The lubrication system is used to provide lubricating oil to the friction surfaces of the specimen; The central control system is used to achieve real-time monitoring and precise control of the gas environment inside the gas environment chamber by controlling the gas supply system.

3. The method as described in claim 2, characterized in that, The gas environment chamber includes a chamber body, a dynamic sealing membrane, an air inlet pipe, a mixing pipe, a heating device, a humidification device, a temperature sensor, a humidity sensor, and a gas sensor; The chamber is a cylindrical body with openings at both ends. The bottom end is fixedly installed on the top surface of the workbench, and the top end is sealed with the dynamic sealing film, thereby forming a sealed space between the workbench, the chamber and the dynamic sealing film. The dynamic sealing film is dynamically sealed to the transmission component; The air inlet pipe penetrates the side wall of the cylinder, with one end connected to the air supply system and the other end connected to the mixing pipe located at the bottom of the chamber, for supplying gas into the mixing pipe; The mixing pipe is provided with multiple small holes; The heating device is fixedly installed on the cylinder and is used to heat the engine oil; The humidification device is used to deliver water vapor into the cabin to regulate the humidity level; The temperature sensor is used to detect the engine oil temperature in real time; The humidity sensor is used to detect the humidity inside the cabin in real time; The gas sensor is used to monitor the concentration of a predetermined gas inside the cabin in real time; The central control system is connected to the heating device, the humidification device, the temperature sensor, the humidity sensor, and the gas sensor, and is used to control the heating device, the humidification device, and the gas supply system.

4. The method as described in claim 3, characterized in that, The gas supply system includes multiple gas cylinders, pressure reducing valves, shut-off valves, check valves, pressure gauges, and mass flow controllers. Each gas cylinder is used to store a different gas and is connected to the inlet pipe via a pipeline; Each pipeline is sequentially equipped with the pressure reducing valve, the shut-off valve, the check valve, the pressure gauge, and the mass flow controller. The mass flow controller is used to control the mass flow rate of the gas to simulate different gas concentrations; The central control system controls the concentration of various gases through various shut-off valves and mass flow controllers.

5. The method as described in claim 3, characterized in that, The cabin is also equipped with an exhaust port that can be opened and closed, and an exhaust pipe connected to the exhaust port. The exhaust pipe is equipped with a filter, and the other end of the exhaust pipe extends outdoors.

6. The method as described in claim 5, characterized in that, The controlled gas environment friction test platform also includes a security system to maintain the safety of the experimental environment; The security system includes an exhaust hood, an audible and visual alarm, a gas sensor, and an explosion-proof fan; The exhaust hood is installed on the top of the friction and wear testing machine; The audible and visual alarm, the gas sensor, and the explosion-proof fan are all connected to the central control system.

7. The method as described in claim 3, characterized in that, The gas environment chamber also includes a pressure sensor installed inside the chamber. The pressure sensor is used to monitor the gas pressure inside the chamber in real time and maintain the gas pressure level inside the chamber through the central control system.

8. The method as described in claim 3, characterized in that, The dynamic sealing film is made of high-strength rubber.

9. The method as described in claim 3, characterized in that, The heating device consists of heating elements / heating rods.

10. The method according to any one of claims 2-9, characterized in that, The central control system adopts a PLC measurement and control system.

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