An engine oil system troubleshooting method and application

Abstract

The application relates to the technical field of engine troubleshooting, in particular to an engine lubricating oil system troubleshooting method and application. The method sequentially carries out targeted troubleshooting on a fault engine, including a lubricating oil tank supercharging valve, a centrifugal ventilator, a lubricating oil tank exhaust channel and an oil return line, removes factors that cause lubricating oil return blockage due to high oil gas pressure in the lubricating oil tank and high oil gas ratio of the oil return pipeline, and continues to troubleshoot the oil return line blockage factors in the front part of the lubricating oil tank, so that the fault position is locked, a systematic troubleshooting method is formed, and the troubleshooting fault points are recorded. The method not only helps to repair the current fault, but also provides valuable data support for subsequent fault analysis and system improvement. The orderly troubleshooting method helps to accurately and quickly locate the fault point, and avoids the problems of low troubleshooting efficiency and long cycle caused by blind troubleshooting.

Description

Technical Field

[0001] This invention relates to the field of engine troubleshooting technology, specifically to a method and application for troubleshooting engine lubricating oil system faults. Background Technology

[0002] The aircraft engine is the heart of an aircraft, its power plant. The working principle of an aircraft engine mainly includes four processes: intake, compression, combustion, and injection. First, air enters the engine through the intake port, is compressed by the compressor to increase its density and pressure. Then, fuel is burned in the combustion chamber, releasing energy. The expanded combustion gases are then ejected, generating thrust. Finally, this thrust acts on the aircraft wings, propelling the aircraft forward. The aircraft engine's lubrication system is a crucial component, responsible for lubricating, cooling, cleaning, and sealing all engine components. It ensures the engine operates normally under harsh conditions such as high speed, high temperature, and high pressure. If the lubrication system malfunctions, such as with oil leaks or insufficient pressure, moving parts will experience excessive wear and overheating due to lack of lubrication. This can even lead to serious problems such as bearing seizure and gear breakage, ultimately causing engine failure and severely threatening flight safety. Timely and effective troubleshooting of the engine's lubrication system ensures the engine is always in optimal working condition, improving its performance and efficiency. Furthermore, it allows for the detection and resolution of problems before they escalate into serious issues, preventing catastrophic accidents. Therefore, timely and effective troubleshooting of the lubricating oil system during the production of aero engines can not only ensure that the overall performance of the engine meets the design requirements, but also promptly identify and resolve problems affecting the performance of the lubricating oil system, eliminating potential safety hazards at the source.

[0003] A certain type of engine repeatedly experienced abnormal oil return in its lubrication system during bench testing. Specifically, the oil level in the engine's oil tank was low under normal operating conditions, but quickly rose after the engine was idled. Troubleshooting this type of fault during engine testing is time-consuming and costly, severely impacting production and delivery schedules. (See also...) Figure 1 Because the engine's lubricating oil system is a reverse circulation system, the hot lubricating oil that lubricates and cools the bearings, gears, and splines directly enters the oil pan. When an abnormal oil return fault occurs during engine testing, the conventional approach is to disassemble the entire engine and check the unobstructed flow of all lubricating oil return lines. This troubleshooting method often lacks specificity, is inefficient, and prone to oversights because the engine's lubricating oil return circuit involves numerous parts and many complex internal oil passages within large housing cavities. In some cases, even after a thorough inspection of the lubricating oil return circuit, the fault remains undetected. Reassembling the engine for testing only leads to the recurrence of the fault, resulting in repeated disassembly and further increasing the difficulty and time required for troubleshooting. Summary of the Invention

[0004] To address the problems of low efficiency and long cycle in troubleshooting engine lubricating system faults during bench testing in existing technologies, this invention provides a method and application for troubleshooting engine lubricating system faults.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention provides a method for troubleshooting engine lubricating oil system faults, comprising:

[0007] S1: Check if the oil tank pressurization valve is faulty; if yes, record the fault point; if no, continue the test run and execute S2.

[0008] S2: Check if the centrifugal fan is faulty; if yes, record the fault point; if no, continue the test run and execute S3.

[0009] S3: Check if the oil tank exhaust passage is faulty. If yes, record the fault point; otherwise, continue the test drive and execute S4.

[0010] S4: Check if there is a fault in the return oil circuit; if yes, record the fault point; if no, proceed to S5.

[0011] S5: Conduct a comprehensive inspection of the lubricating oil system housing and related pipelines until the fault point is found and recorded, thus completing the troubleshooting of the engine lubricating oil system.

[0012] Optionally, the specific method of S1 is as follows:

[0013] Replace the engine's oil tank booster valve and continue test driving. If the problem persists, then troubleshoot the oil tank booster valve.

[0014] If the fault is resolved, the problem lies with the oil tank pressurization valve.

[0015] When the oil tank booster valve malfunctions, test the engine's oil tank booster valve opening pressure under test bench conditions. If the opening pressure exceeds the upper limit, the cause of the malfunction is determined to be excessive oil tank booster valve opening pressure.

[0016] Optionally, the specific operation of S2 is as follows:

[0017] Replace the centrifugal ventilator and continue the test run. If the fault is resolved, record the fault as the centrifugal ventilator; if the fault is not resolved, eliminate the centrifugal ventilator as the faulty component.

[0018] Optionally, the specific method of S3 is as follows:

[0019] Replace the oil tank and continue the test drive. If the fault is resolved, record the fault as the oil tank; if the fault is not resolved, troubleshoot the oil tank venting passage.

[0020] If the fault is in the oil tank, disassemble and inspect the oil tank of the faulty engine to determine the fault location.

[0021] Optionally, the specific method of S4 is as follows:

[0022] Check the oil drain volume of the internal gear oil tank, main return oil line, auxiliary gearbox and high-speed gearbox in turn to see if there is any abnormality, and record the points where the oil drain volume is abnormal.

[0023] Optionally, when the oil drain volume from the internal gear tank is abnormal, the engine internal gear housing and related pipelines are disassembled to determine the fault point and record it.

[0024] Optionally, when the oil drain volume of the main return line is abnormal, the engine bearing housing and related pipelines are disassembled to determine the fault point and record it.

[0025] Optionally, when the auxiliary gearbox oil drain volume is abnormal, the engine auxiliary gearbox housing and related pipelines are disassembled to determine the fault point and record it.

[0026] Optionally, when the oil drain volume of the high-speed gearbox is abnormal, the engine high-speed gearbox housing and related pipelines are disassembled to determine the fault point and record it.

[0027] The above-mentioned troubleshooting methods for engine lubricating oil system are applied in engine fault detection.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention discloses a method for troubleshooting engine lubrication systems. This method involves sequentially inspecting the oil tank pressurization valve, centrifugal ventilator, oil tank exhaust passage, and return oil circuit of the faulty engine. It eliminates factors such as high oil-air pressure in the oil tank and high oil-air ratio in the return oil line causing obstruction of oil return. Further investigation is conducted on blockages in the return oil circuit at the front of the oil tank to pinpoint the fault location. This systematic troubleshooting method, by recording the identified fault points, not only aids in the immediate repair of the fault but also provides valuable information for subsequent fault analysis and system improvement. Data support and statistical analysis of fault points can identify weak links in the lubricating oil system, allowing for targeted improvement measures. This systematic troubleshooting approach helps to accurately and quickly locate fault points, avoiding inefficiency and missed detections caused by blind troubleshooting. Compared to the traditional method of directly disassembling the entire faulty engine and checking the unobstructed flow of all lubricating oil return lines, this method is highly targeted in troubleshooting, avoiding the inefficiency and long cycle caused by blind troubleshooting, while saving manpower and resources, thus possessing a certain degree of economic efficiency.

[0030] By directly replacing the oil tank pressure booster valve and conducting a test run, it's possible to quickly verify whether this component is the source of the fault. This method avoids complex testing processes and can determine whether there is a problem with the oil tank pressure booster valve in a short time, improving the efficiency of fault diagnosis. Accurate determination of the fault cause also helps in improving the engine's lubrication system. Therefore, when the fault is with the oil tank pressure booster valve, the opening pressure of the engine's oil tank pressure booster valve is tested on a test bench to determine the cause of the fault, providing support for subsequent fault repair and lubrication system improvements.

[0031] By directly replacing the centrifugal ventilator and observing the test results, it is possible to quickly determine whether the component is the source of the fault. This direct replacement verification method avoids a complex item-by-item testing process and significantly improves the efficiency of fault location.

[0032] By directly replacing the oil tank and conducting a test run, it is possible to quickly determine whether the oil tank is the source of the fault. This method is direct and effective, avoiding redundant checks on other unrelated components during troubleshooting and significantly improving the accuracy of fault location.

[0033] The oil drain volume of the internal gear oil tank, main return oil line, auxiliary gearbox, and high-speed gearbox was checked sequentially for any abnormalities, and the points of abnormal oil drain volume were recorded. This systematic inspection method, which comprehensively covers the key components in the return oil line, helps to ensure that no possible fault points are missed, improves the comprehensiveness of fault diagnosis, facilitates the rapid development of subsequent maintenance work, and improves maintenance efficiency.

[0034] When the oil drain volume of specific components (such as the internal gear oil tank, main return line, auxiliary gearbox, and high-speed gearbox) is abnormal, a thorough inspection by disassembling the relevant housing and pipelines can accurately pinpoint the fault. This method avoids blind troubleshooting, improves the accuracy and efficiency of fault diagnosis, provides detailed fault information for subsequent maintenance and improvement, reduces maintenance time and costs, provides a reliable basis for understanding the weak points of the engine lubrication system, provides guidance for future preventive maintenance, helps extend the engine's service life, and improves the system's reliability.

[0035] The above-mentioned troubleshooting methods for engine lubrication systems are applied in engine fault detection. By employing these systematic, standardized, and comprehensive methods, no potential fault points are overlooked, improving the accuracy of fault detection, avoiding blind troubleshooting and unnecessary checks, significantly shortening fault detection time, and increasing engine fault detection efficiency. This provides strong support for continuous system improvement and contributes to enhancing engine performance and reliability. Attached Figure Description

[0036] Figure 1 This is a diagram of the return oil flow path of a certain engine's lubrication system.

[0037] Figure 2 This is a structural diagram of the oil-gas separation and exhaust channel of the lubricating oil tank.

[0038] Figure 3 This is a diagram showing the oil flow path of the lubricating oil system.

[0039] Figure 4 This is a diagram of the return oil flow path for the lubricating oil system.

[0040] Figure 5 This is a flowchart illustrating a method for troubleshooting engine lubricating oil system faults according to the present invention.

[0041] Figure 6 This is a flowchart illustrating the specific process of a method for troubleshooting engine lubricating oil system faults according to the present invention.

[0042] Among them, 1-boost valve, 2-auxiliary gearbox return oil line, 3-high-speed gearbox return oil line, 4-centrifugal ventilator, 5-combined return oil line, 6-internal gearbox oil-gas line, 7-bearing oil-gas line, 8-internal gearbox return oil line, 9-high-pressure thrust bearing return oil line, 10-high-vortex bearing return oil line, 11-low-vortex bearing return oil line, 12-main return oil line, 13-high-speed gearbox return oil, 14-spherical valve, 15-oil tank exhaust channel, 16-auxiliary gearbox return oil, 17-return oil pump return oil, 18-oil-gas separator. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0045] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0046] See Figure 1 This is a lubrication system for a certain engine. This system is a reverse circulation system, where hot lubricating oil that lubricates and cools bearings, gears, and splines directly enters the oil tank. The system includes: a booster valve 1, an auxiliary gearbox return line 2, a high-speed gearbox return line 3, a centrifugal ventilator 4, a combined return line 5, an internal gearbox oil-air line 6, a bearing oil-air line 7, an internal gearbox return line 8, a high-pressure thrust bearing return line 9, a high-vortex bearing return line 10, and a low-vortex bearing return line 11. This type of engine has repeatedly experienced abnormal oil return failures in its lubrication system during bench testing. Specifically, the oil level in the engine tank is low under normal operating conditions during testing, but quickly rises after the engine is idle. Troubleshooting this type of failure during engine testing is time-consuming and costly, severely impacting production and delivery schedules.

[0047] Abnormal oil return in the lubricating oil system is a manifestation of an imbalance between oil supply and return. In addition to a blocked return oil path, high oil-air pressure in the oil tank and a high oil-air ratio in the lubricating oil cavity can also inhibit the speed and flow of return.

[0048] See Figure 2 The oil pressure inside the oil tank is high. The return oil pump 17, containing a large number of oil bubbles after operation, sends the high-temperature return oil 17 back to the oil tank. Above the return oil pump 17 are, in sequence, the auxiliary gearbox return oil 16, the oil tank exhaust passage 15, the spherical valve 14, and the high-speed gearbox return oil 13. An oil-gas separator 18 is installed in the upper part of the oil tank, and the oil tank return main pipe 12 is above the oil-gas separator 18. In this way, the diverted oil falls to the bottom of the tank, while the air containing a small amount of oil mist rises to the top of the tank. A spherical valve 14 is installed at the top of the tank. During normal flight, this spherical valve 14 is open. At this time, the oil and gas at the top of the tank enter the housing of the upper spherical valve 14 through the vent pipe at the top of the tank, and then are discharged to the auxiliary gearbox return oil line 2 through the oil tank booster valve 1. The oil tank booster valve 1 ensures that the pressure inside the engine oil tank is always 0.021 MPa higher than the pressure in the auxiliary gearbox.

[0049] After fault analysis, the main fault types include excessive opening pressure of the oil tank booster valve 1, obstruction of the oil tank exhaust passage, and blockage of the return oil circuit.

[0050] Excessive opening pressure of oil tank booster valve 1: The function of oil tank booster valve 1 is to make the oil-gas pressure in the oil tank 0.021MPa higher than the oil-gas pressure in the auxiliary gearbox. If the opening pressure of engine oil tank booster valve 1 is too high, the oil-gas pressure in the engine oil tank will also be too high. When this pressure is high enough, it will hinder the return of lubricating oil to the oil tank, resulting in abnormal oil return fault.

[0051] Blocked venting passage in the lubricating oil tank: If the oil and gas passage inside the lubricating oil tank is blocked, the pressure of the oil and gas accumulating in the lubricating oil tank will inevitably increase. When this pressure reaches a certain level, it will prevent the lubricating oil from returning to the lubricating oil tank, resulting in abnormal oil return faults.

[0052] High oil-air ratio in return oil line: This indicates a problem with the oil flow path in the lubrication system. Figure 3 As shown, the lubricating oil from the bearing oil-gas pipeline 7, the internal gearbox oil-gas pipeline 6, and the lubricating oil tank oil-gas pipeline flows through the high-speed gearbox return oil pipeline 3 to the centrifugal ventilator 4. The centrifugal ventilator 4 then separates the oil and gas and expels the air outside the machine. If the oil-gas separation is ineffective, the return oil pipeline will contain a large number of air bubbles, reducing the actual amount of oil circulating back to the lubricating oil tank. The effectiveness of the oil-gas separation depends on the proper functioning of the centrifugal ventilator 4 and the unobstructed flow of the lubricating oil system's oil-gas pipelines.

[0053] Oil return path blockage: See Figure 4 The lubricating oil from the internal gearbox return line 8, the high-pressure thrust bearing return line 9, the high-speed vortex bearing return line 10, and the low-speed vortex bearing return line 11 enters the lubricating oil tank via the main return line 12, together with the lubricating oil from the high-speed gearbox return line 3 and the auxiliary gearbox return line 2. Clearly, a reduced flow area in the return oil path will directly lead to abnormal lubricating oil return from the lubricating oil tank. When an abnormal lubricating oil return fault occurs, the unobstructed flow of the return lines needs to be checked.

[0054] To address the above problems, this invention provides a method for troubleshooting engine lubrication systems, see [link to relevant documentation]. Figure 5 and Figure 6 ,include:

[0055] S1: Check if the oil tank pressurization valve 1 is faulty; if yes, record the fault point; if no, continue the test run and execute S2, specifically:

[0056] Replace the engine oil tank booster valve 1 and continue the test drive. If the fault is not resolved, troubleshoot the oil tank booster valve and execute S2.

[0057] If the fault is resolved, the problem lies with the oil tank pressurization valve.

[0058] When the oil tank booster valve malfunctions, test the engine's oil tank booster valve opening pressure under test bench conditions. If the opening pressure exceeds the upper limit, the cause of the malfunction is determined to be excessive oil tank booster valve opening pressure.

[0059] S2: Check if centrifugal ventilator 4 is faulty; if yes, record the fault point; if no, continue the test run and execute S3, specifically:

[0060] Replace centrifugal ventilator 4 and continue the test run. If the fault is resolved, record the fault point as centrifugal ventilator 4; if the fault is not resolved, troubleshoot centrifugal ventilator 4 and execute S3.

[0061] S3: Check if the oil tank vent passage is faulty. If yes, record the fault point; otherwise, continue the test drive and execute S4, specifically:

[0062] Replace the oil tank and continue the test drive. If the fault is resolved, record the fault location as the oil tank. If the fault is not resolved, troubleshoot the oil tank venting passage and execute S4.

[0063] If the fault is in the oil tank, disassemble and inspect the oil tank of the faulty engine to determine the fault location.

[0064] S4: Check if there is a fault in the return oil circuit; if yes, record the fault point; if no, proceed to S5, specifically:

[0065] Check the oil drain volume of the internal gear oil tank, main return oil line 12, auxiliary gearbox and high-speed gearbox in turn to see if there is any abnormality, and record the points where the oil drain volume is abnormal.

[0066] The specific method for checking the drain volume of the internal gear oil tank, main return line 12, auxiliary gearbox, and high-speed gearbox is as follows: After the engine is stopped, without performing a cold start procedure, immediately extract oil samples from the drain ports of the four lubricating oil storage chambers, namely the internal gearbox, main return line 12, auxiliary gearbox, and high-speed gearbox (drain for 5 minutes and collect with a measuring cup). Compare the lubricating oil volume collected from the four drain ports with the empirical value of sampling from a normal engine with normal return oil. If no obvious abnormality is found in the volume comparison, proceed with S5.

[0067] When the oil drain volume from the internal gear tank is abnormal, disassemble the engine internal gearbox housing and related pipelines to determine the fault point and record it.

[0068] When the oil discharge from the main return oil line 12 is abnormal, disassemble the engine bearing housing and related pipelines to determine the fault point and record it.

[0069] When the auxiliary gearbox oil drain volume is abnormal, disassemble the engine auxiliary gearbox housing and related pipelines to determine the fault point and record it.

[0070] When the oil drain volume of the high-speed gearbox is abnormal, disassemble the engine high-speed gearbox housing and related pipelines to determine the fault point and record it.

[0071] S5: Conduct a comprehensive inspection of the lubricating oil system housing and related pipelines until the fault point is found and recorded. Complete the troubleshooting of the engine lubricating oil system. This mainly involves a comprehensive inspection of the lubricating oil tank system housing and related pipelines, checking the unobstructed flow of lubricating oil, and checking the orifice size if necessary.

[0072] Example 1

[0073] During a bench test of an engine, the lubrication system experienced slow oil return while the engine was running. The engine oil tank pressure booster valve was disassembled on the test bench, and its opening pressure was found to be exceeding the upper limit. The fault was resolved by replacing the oil tank pressure booster valve 1 while the engine was running on the test bench. The cause of the fault was excessive opening pressure of the oil tank pressure booster valve 1.

[0074] Example 2

[0075] After a bench test of an engine, there was no oil level in the oil tank after the test was stopped. Following the troubleshooting process, the booster valve 1 assembly was replaced, but the fault persisted after a retest. Then, the centrifugal ventilator 4 was replaced, and the fault was resolved after a retest. Therefore, the cause of the engine fault was determined to be a high air-fuel ratio in the return oil line.

[0076] Example 3

[0077] During a bench test of an engine, there was no oil level in the main oil tank when the engine was in a normal operating state. After 30 seconds of idle operation, oil began to appear in the tank. Following the troubleshooting procedure, the booster valve assembly 1 was replaced, but the fault persisted after a retest. Next, the centrifugal ventilator 4 was replaced, but the fault remained. Replacing the oil tank resolved the problem. Upon disassembly and inspection of the engine's oil tank, it was discovered that the auxiliary return oil pipe orifice in the vent pipe of the left upper ball valve was smaller than that of a normal engine. This caused a severe imbalance between the return and supply oil volumes in the normal operating state, resulting in no oil level in the tank during the normal operating state.

[0078] Example 4

[0079] During a bench test of an engine, there was no oil level in the main lubricating oil tank when the engine was in its normal operating state. Even after returning to idle, there was still no oil level in the main lubricating oil tank. After running at idle for 2 minutes, an oil level appeared and quickly rose. Oil was drained from the high-speed, auxiliary, internal gearbox, and main return oil lines. Comparison with a normal engine revealed that the high-speed gearbox had a significant amount of oil remaining. The auxiliary gearbox pressure valve 2, centrifugal ventilation pipe 4, and lubricating oil tank were checked on the bench, but the fault persisted. The initial assessment was that the fault might be related to the unobstructed flow of the high-speed gearbox's return oil circuit. After disassembling and inspecting the engine, it was found that the hole for the magnetic caliper to the oil filter on the high-speed gearbox housing was too small. After machining and reassembly, the fault was resolved during the test run. In this specific case, an obstructed return oil circuit caused a severe imbalance between the return oil volume and the supply oil volume in the normal operating state, manifesting as no oil level in the main lubricating oil tank in the normal operating state.

[0080] The above-mentioned troubleshooting methods for engine lubrication systems are applied in engine fault detection. By employing these systematic, standardized, and comprehensive methods, no potential fault points are overlooked, improving the accuracy of fault detection, avoiding blind troubleshooting and unnecessary checks, significantly shortening fault detection time, and increasing engine fault detection efficiency. This provides strong support for continuous system improvement and contributes to enhancing engine performance and reliability.

[0081] In summary, this invention provides a method and application for troubleshooting engine lubricating oil systems. By replacing the oil tank pressure booster valve 1, the centrifugal ventilator 4, and the oil tank, factors such as high oil-gas pressure in the oil tank and high oil-gas ratio in the return oil line, which obstruct oil return, are eliminated. Further investigation is conducted into blockages in the return oil line at the front of the oil tank. This is achieved by extracting the oil volume in the four lubricating oil chambers over a certain period and comparing it with empirical values ​​from samples taken from engines with normal return oil levels, thus pinpointing the fault location. Compared to the traditional method of blindly disassembling the engine lubricating oil system, this method is more effective and targeted in troubleshooting, with higher efficiency and a shorter cycle time.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for troubleshooting engine lubricating oil system faults, characterized in that, include: S1: Check if the oil tank pressurization valve is faulty; if yes, record the fault point; if no, continue the test run and execute S2, specifically: Replace the engine's oil tank booster valve and continue test driving. If the problem persists, then troubleshoot the oil tank booster valve. If the fault is resolved, the problem lies with the oil tank pressurization valve. When the oil tank pressurization valve is faulty, test the opening pressure of the oil tank pressurization valve of the engine under test bench conditions. If the opening pressure is found to exceed the upper limit, the fault is determined to be caused by the excessive opening pressure of the oil tank pressurization valve. S2: Check if the centrifugal fan is faulty; if yes, record the fault point; if no, continue the test run and execute S3, specifically: Replace the centrifugal ventilator and continue the test run. If the fault is resolved, record the fault as the centrifugal ventilator; if the fault is not resolved, troubleshoot the centrifugal ventilator. S3: Check if the oil tank vent passage is faulty. If yes, record the fault point; otherwise, continue the test drive and execute S4, specifically: Replace the oil tank and continue the test drive. If the fault is resolved, record the fault as the oil tank; if the fault is not resolved, troubleshoot the oil tank venting passage. If the fault is in the oil tank, disassemble and inspect the oil tank of the faulty engine to determine the fault location. S4: Check if there is a fault in the return oil circuit; if yes, record the fault point; if no, proceed to S5, specifically: Check the oil drain volume of the internal gear oil tank, main return oil line, auxiliary gearbox and high-speed gearbox in turn to see if it is abnormal, and record the abnormal oil drain volume points; S5: Conduct a comprehensive inspection of the lubricating oil system housing and related pipelines until the fault point is found and recorded, thus completing the troubleshooting of the engine lubricating oil system.

2. The method for troubleshooting engine lubricating oil system malfunctions according to claim 1, characterized in that, When the oil drain volume from the internal gear tank is abnormal, disassemble the engine internal gearbox housing and related pipelines to determine the fault point and record it.

3. The method for troubleshooting engine lubricating oil system malfunctions according to claim 1, characterized in that, When the oil drain volume of the main return line is abnormal, disassemble the engine bearing housing and related pipelines to determine the fault point and record it.

4. The method for troubleshooting engine lubricating oil system malfunctions according to claim 1, characterized in that, When the auxiliary gearbox oil drain volume is abnormal, disassemble the engine auxiliary gearbox housing and related pipelines to determine the fault point and record it.

5. The method for troubleshooting engine lubricating oil system malfunctions according to claim 1, characterized in that, When the oil drain volume of the high-speed gearbox is abnormal, disassemble the engine high-speed gearbox housing and related pipelines to determine the fault point and record it.

6. The application of the engine lubricating oil system fault diagnosis method according to any one of claims 1-5 in engine fault detection.

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