Oil tank for an aero-engine and aero-engine

Abstract

The application provides an oil tank of an aero-engine, comprising: a tank body configured as a U-shaped structure with an opening facing upwards, and a U-shaped cavity formed inside; and an oil-gas separator integrally formed with the tank body at one end of the tank body, and comprising: a shell with a separation channel formed inside and communicating with the cavity and an oil return system of the aero-engine; an exhaust cylinder with a gas outlet at one end, arranged in the separation channel, and the gas outlet communicating with the cavity; a cyclone plate configured as a spiral line and surrounding the exhaust cylinder and the shell to form a spiral channel; and the exhaust cylinder having a plurality of exhaust holes communicating with the spiral channel and the gas outlet, wherein after the oil-gas mixture from the oil return system enters the spiral channel, the oil droplets in the oil-gas mixture are thrown to the inner wall surface of the shell under the action of centrifugal force and flow into the cavity, and the gas in the oil-gas mixture is discharged through the exhaust holes and the gas outlet.

Description

Technical Field

[0001] At least one embodiment of this application relates to the field of aero-engine technology, and more particularly to an oil tank for an aero-engine and an aero-engine. Background Technology

[0002] Aero engines integrate a variety of high-speed rotating components, among which bearings, gears, and other friction pairs bear enormous loads during operation. To ensure their efficient and continuous operation, the lubrication system needs to continuously supply lubricating oil to reduce friction, minimize wear, and achieve effective cooling. A typical lubrication system consists of key components such as an oil tank, oil supply pump, oil filter, oil return pump, ventilator, oil-gas separator, and radiator.

[0003] During operation, lubricating oil mixes with the sealed air to form an oil-air mixture. Air bubbles in this mixture increase flow resistance in the pipeline, reduce the specific heat capacity and thermal conductivity of the lubricating oil, and weaken its heat dissipation and lubrication effects. Simultaneously, a large amount of oil-air mixture flowing back into the oil tank can cause an increase in internal pressure, which is detrimental to the oil return process. Summary of the Invention

[0004] In view of this, this application provides an oil tank for an aircraft engine and an aircraft engine, which can effectively separate oil-gas mixtures, reduce the number of parts, and reduce the risk of leakage.

[0005] According to the present invention, an oil tank for an aircraft engine includes: a housing configured as an upward-opening U-shaped structure with a U-shaped cavity inside; an oil-gas separator integrally formed with the housing at one end of the housing and including: a shell having a separation channel inside that connects the cavity and the oil return system of the aircraft engine; an exhaust pipe with an outlet at one end disposed within the separation channel, the outlet communicating with the cavity; and a swirl plate configured as a spiral and surrounding the exhaust pipe and the shell to form a spiral channel; the exhaust pipe having a plurality of exhaust holes connecting the spiral channel and the outlet, wherein after the oil-gas mixture from the oil return system enters the spiral channel, oil droplets in the oil-gas mixture are thrown against the inner wall of the shell and flow into the cavity under centrifugal force, and gas in the oil-gas mixture is discharged through the exhaust holes and the outlet.

[0006] According to an embodiment of this application, the diameter of the spiral channel gradually decreases or increases along the flow direction of the oil-gas mixture.

[0007] According to an embodiment of this application, a plurality of the above-mentioned exhaust holes are arranged in a spiral shape in the middle of the above-mentioned spiral channel along the extension direction of the spiral channel.

[0008] According to an embodiment of this application, the number of turns of the plurality of the above-mentioned exhaust holes is 50% to 80% of the total number of turns of the above-mentioned spiral channel.

[0009] According to an embodiment of this application, the helix angle of the swirl plate is 15° to 45°.

[0010] According to an embodiment of this application, along the flow direction of the oil-gas mixture, the separation channel located at the front end of the spiral channel is configured as a tapered structure to increase the circumferential velocity of the oil-gas mixture.

[0011] According to an embodiment of this application, the aforementioned lubricating oil tank further includes a level gauge disposed in the aforementioned tank body, which is suitable for detecting the level of oil in the aforementioned cavity.

[0012] According to an embodiment of this application, the above-mentioned oil tank further includes: an oil filling port, which can be closedly disposed at the other end of the tank body, suitable for adding lubricating oil into the cavity when the tank is open.

[0013] According to an embodiment of this application, the outlet position of the above-mentioned air outlet is higher than the designed highest oil level in the above-mentioned cavity.

[0014] According to another aspect of the embodiments of this application, an aircraft engine is provided, including an engine body; any of the above-mentioned oil tanks are disposed in the engine body and are adapted to provide lubricating oil to the engine body.

[0015] According to embodiments of this application, the U-shaped design (U-shaped structure with the opening facing upwards) of the oil tank allows it to be mounted on a protruding part of the engine core or accessory gearbox. Specifically, a portion of the engine (e.g., the outer edge of the casing, piping, or mounting base) can pass through or be embedded in the opening of the tank, thereby achieving compact integration of the engine and the oil tank within a limited space. This U-shaped structure not only effectively avoids protruding engine components, saving installation space, but also facilitates the fixing and positioning of the oil tank on the engine body, while providing an operating channel for subsequent maintenance (such as oil filling and level observation). Furthermore, the U-shaped cavity helps maximize the oil storage volume within a confined space and maintain continuous fuel supply during engine maneuvering flight. Attached Figure Description

[0016] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0017] Figure 1 A perspective view of a lubricating oil tank according to an embodiment of this application is schematically shown;

[0018] Figure 2 A schematic cross-sectional view of the lubricating oil tank according to an embodiment of this application is shown.

[0019] The annotations in the attached figures are explained as follows:

[0020] 1. Box body; 11. Cavity;

[0021] 2. Oil-gas separator; 21. Shell; 22. Exhaust stack; 221. Exhaust port; 23. Swirl plate;

[0022] 3. Level gauge;

[0023] 4. Oil cap. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0026] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0027] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Similarly, when using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0028] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this application. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this application.

[0029] In the process of developing this application, it was discovered that an oil-gas separator is required in the lubrication system of an aircraft engine to separate the oil-gas mixture in the return oil, so as to ensure the safe operation of bearings and gears and maintain system stability.

[0030] The hydrodynamic oil-gas separator utilizes centrifugal force to achieve gas-liquid separation, offering advantages such as compact structure, light weight, and simple manufacturing. Its working principle is as follows: the oil-gas mixture enters through the inlet, gains a large circumferential velocity in the pre-swirl section, and flows downwards under gravity. Due to the significant density difference between oil and air, oil droplets are thrown against the outer wall by centrifugal force, entering the storage chamber and separation section, and ultimately flowing back to the oil tank; the separated air is discharged through the exhaust port.

[0031] In related technologies, hydrodynamic oil-gas separators are mostly independent components, installed between the return oil pump and the lubricating oil tank, and fixed by flanges, bolts, or welding. This split structure has problems such as a large number of parts, multiple assembly and sealing interfaces, high leakage risk, large space occupation, and increased oil circuit length and pressure drop; manufacturing and assembly costs are high, and the connection points are easily affected by vibration and thermal expansion and contraction during long-term operation, which reduces reliability.

[0032] In addition, due to the limited internal space of aero engines, conventional straight-cylinder, tangentially inlet-type hydrodynamic oil-gas separators have low separation efficiency under high oil-gas ratio conditions; when the return oil pump does not pump oil in time, lubricating oil is prone to accumulate inside the separator, increasing lubricating oil consumption and affecting system performance.

[0033] Figure 1 A perspective view of a lubricating oil tank according to an embodiment of this application is schematically shown. Figure 2 A schematic cross-sectional view of the lubricating oil tank according to an embodiment of this application is shown.

[0034] According to one aspect of the embodiments of this application, an oil tank for an aircraft engine is provided. For example... Figure 1 and Figure 2 As shown, the lubricating oil tank includes a housing 1 and an oil-gas separator 2. The housing 1 is constructed as a U-shaped structure with the opening facing upwards, forming a U-shaped cavity 11 inside. The oil-gas separator 2 is integrally formed with the housing 1 at one end of the housing 1 and includes a shell 21, an exhaust pipe 22 with an outlet at one end, and a swirl plate 23. The shell 21 forms a separation channel inside, connecting the cavity 11 and the oil return system of the aircraft engine. The exhaust pipe 22 is disposed within the separation channel, and its outlet communicates with the cavity 11. The swirl plate 23 is constructed as a spiral and surrounds the exhaust pipe 22 and the shell 21 to form a spiral channel. The exhaust pipe 22 has multiple exhaust holes 221 connecting the spiral channel and the outlet, from which the oil-gas mixture (such as...) from the oil return system... Figure 2After entering the spiral channel (in the direction indicated by the middle arrow), the oil droplets in the oil-gas mixture are thrown towards the inner wall of the shell 21 and flow into the cavity 11 under the action of centrifugal force, and the gas in the oil-gas mixture is discharged through the exhaust port 221 and the gas outlet.

[0035] According to embodiments of this application, the U-shaped design (U-shaped structure with the opening facing upwards) of the oil tank allows it to be mounted on a protruding part of the engine core or accessory gearbox. Specifically, a portion of the engine (e.g., the outer edge of the casing, piping, or mounting base) can pass through or be embedded in the opening of the housing 1, thereby achieving compact integration of the engine and the oil tank within a limited space. This U-shaped structure not only effectively avoids protruding engine components, saving installation space, but also facilitates the fixing and positioning of the oil tank on the engine body, while providing an operating channel for subsequent maintenance (such as oil filling and level observation). Furthermore, the U-shaped cavity 11 helps to maximize the oil storage volume within a confined space and maintain continuous fuel supply during engine maneuvering flight.

[0036] According to an embodiment of this application, the air outlet may be located at the lower end of the exhaust pipe 22.

[0037] According to the embodiments of this application, the lubricating oil tank, the tank body 1 and the oil-gas separator 2 can be integrally formed by additive manufacturing technology. The material can be selected from aerospace-grade aluminum alloy, titanium alloy or stainless steel to meet the requirements of strength, corrosion resistance and temperature resistance.

[0038] It should be understood that the housing 1 is also provided with an exhaust port (not shown in the figure), which is connected to the cavity 11 and is used to balance the air pressure inside and outside the lubricating oil tank, so that the gas that has been separated and accumulated in the upper part of the cavity 11 can be finally discharged from the housing 1. The exhaust port can be set separately on the wall of the housing 1, or it can be connected to the ventilation system of the aircraft engine.

[0039] According to the embodiment of this application, in the lubricating oil tank, the oil-gas mixture from the return oil system enters the spiral channel and generates a high-speed swirling flow under the guidance of the spiral swirl plate 23. Utilizing the density difference between oil droplets and gas, the oil droplets are thrown towards the inner wall of the shell 21 under the action of strong centrifugal force and flow directly into the U-shaped cavity 11 for recycling. The separated gas is discharged through the exhaust port 221 and the outlet, achieving efficient gas-liquid separation. The integrated design of the oil-gas separator 2 and the tank 1 eliminates the need for a separate separator shell 21, flange, bolts, and seals, reducing the number of parts and assembly interfaces. This avoids the risk of loose connections and seal failure due to vibration and thermal expansion and contraction, improving the reliability of long-term operation.

[0040] In addition, the U-shaped housing 1 structure can avoid core engine components within the limited engine installation space, while increasing the lubricating oil storage capacity. The oil-gas separator 2 is built into one end of the housing 1 and does not require external piping, which shortens the oil return path and reduces the flow pressure drop, achieving a compact layout and efficient space utilization.

[0041] According to embodiments of this application, the housing 21 of the oil-gas separator 2 can be printed on the casing 1 at various angles; that is, the outlet of the oil-gas separator 2 can be downward, horizontal, or at any angle between downward and horizontal. Correspondingly, the direction of the oil-gas mixture inlet also changes synchronously with the printing angle of the housing 21.

[0042] According to embodiments of this application, the housing 21 can be a separate part, directly formed by additive manufacturing (3D printing), and integrally printed with or subsequently connected to the oil tank body 1. In this way, the housing 21 of the oil-gas separator is an independent structure specifically designed for the oil-gas separation function, with high manufacturing precision and arbitrarily optimized shape.

[0043] In some other illustrative embodiments, the housing 21 of the oil-gas separator 2 is not limited to a separately formed structure. Since the gearbox of an aircraft engine (especially the accessory gearbox) is typically located near the oil tank, and the gearbox housing itself has a certain volume and structural strength, a portion of the gearbox housing can be directly used as the outer shell of the oil-gas separator 2. Specifically, the separation channel, spiral swirl plate 23, and exhaust stack 22 required by the oil-gas separator 2 are directly formed in the wall surface or internal cavity 11 of the gearbox housing through additive manufacturing or precision casting. In this case, a portion of the gearbox housing wall performs the function of the oil-gas separator 2 housing 21, which originally needed to be manufactured separately; that is, the gearbox housing and the oil-gas separator 2 housing 21 share the same solid structure.

[0044] This eliminates the need for a separate oil-gas separator 2 housing 21 and the connecting flange, bolts, and seals between the oil-gas separator 2 and the gearbox, further reducing the number of parts and system weight. Furthermore, the oil-gas separator 2 is directly integrated into the gearbox housing, shortening the return oil line and exhaust line, reducing flow resistance and leakage risk. Utilizing the existing gearbox housing space eliminates the need for additional external engine mounting space, resulting in a more compact overall layout. This allows for metal additive manufacturing processes, enabling the internal flow channels of the oil-gas separator 2 to be integrally formed while printing the gearbox housing, achieving a high degree of structural integration and functional fusion.

[0045] According to embodiments of this application, such as Figure 2 As shown, the diameter of the spiral channel gradually decreases or increases along the flow direction of the oil-gas mixture.

[0046] In some illustrative embodiments, the diameter of the spiral channel is along the flow direction of the oil-gas mixture (e.g., Figure 2 As shown, the flow rate of the oil-gas mixture gradually increases as the cross-sectional area of ​​the channel decreases, thus enhancing the centrifugal force field and making it easier for fine oil droplets to be thrown towards the inner wall of the shell 21. This method is suitable for efficient separation under conditions of high oil-gas ratio or low flow rate.

[0047] In other illustrative embodiments, the diameter of the spiral channel gradually expands along the flow direction of the oil-gas mixture. During the flow of the oil-gas mixture, the flow velocity gradually decreases, which prolongs the residence time of the oil-gas mixture in the spiral channel. This allows the oil droplets to fully aggregate and settle, while reducing flow resistance. This makes it suitable for high flow rates or pressure drop-sensitive operating conditions.

[0048] In some illustrative embodiments, the diameter of the helical channel is set to be constant along the flow direction of the oil-gas mixture. The constant-diameter helical channel structure is relatively simple, easy to achieve through additive manufacturing or machining, reducing manufacturing difficulty and cost. It also helps maintain the stability and consistency of flow within the channel, avoiding local velocity fluctuations or eddy current losses caused by diameter changes. Furthermore, the constant-diameter design allows the oil-gas mixture to flow at a relatively constant linear velocity within the helical channel, resulting in a uniform centrifugal force field. This is suitable for operating scenarios with small fluctuations in the oil-gas ratio and relatively stable flow rates, providing predictable pressure drop characteristics while ensuring basic separation efficiency, facilitating the matching design of the lubricating oil system.

[0049] According to embodiments of this application, such as Figure 2 As shown, multiple exhaust holes 221 are located in the middle of the spiral channel and are arranged in a spiral shape along the extension direction of the spiral channel.

[0050] In this embodiment, the vent 221 is arranged in the middle of the spiral channel rather than along its entire length, so that the oil-gas mixture can be fully centrifugally separated in the first half of the spiral channel, and the oil droplets have enough time to be thrown against the inner wall of the housing 21, thus preventing the oil and gas from escaping from the vent 221 too early and resulting in incomplete separation.

[0051] The exhaust ports 221 are arranged in a spiral shape along the extension direction of the spiral channel, which is consistent with the swirling direction of the airflow in the spiral channel. This allows the separated gas to enter the exhaust ports 221 through the shortest and smoothest path, reducing local resistance and eddy current loss of gas flow and lowering the pressure drop.

[0052] In addition, the spirally arranged exhaust holes 221 are evenly distributed along the circumference of the channel, which avoids the gas from being concentrated on one side and can maintain the symmetry and stability of the flow field in the spiral channel, prevent secondary entrainment of oil droplets due to flow deviation, and optimize the smoothness of gas discharge while ensuring high separation efficiency, thus improving the overall working performance of the oil-gas separator 2.

[0053] In the process of realizing this application, it was found that if the number of coverage rings of the vent hole 221 is too small, the gas discharge channel is insufficient, which can easily lead to the accumulation of separated gas in the spiral channel, increasing local pressure and interfering with the newly entering oil-gas mixture. At the same time, it may cause the separated oil droplets to be re-entrained by the airflow. If the number of coverage rings of the vent hole 221 is too large (e.g., close to 100%), the oil-gas mixture may escape from the early vent hole 221 before it is fully centrifuged and separated, causing the fine oil droplets to be discharged with the gas before they are thrown to the wall, reducing the separation efficiency.

[0054] According to embodiments of this application, such as Figure 2 As shown, the number of turns of the multiple exhaust holes 221 is 50% to 80% of the total number of turns of the spiral channel.

[0055] For example, the number of turns of the multiple exhaust holes 221 can be any value among 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, and 80% of the total number of turns of the spiral channel.

[0056] In this embodiment, by optimizing the ratio range to 50%–80%, sufficient centrifugal acceleration and oil droplet ejection are ensured in the initial section of the spiral channel (approximately 30%–50% of the revolutions), allowing for early separation of most of the oil. Simultaneously, the separated gas is discharged smoothly and promptly in the middle and later sections (approximately 50%–80% of the revolutions), while the final section of the channel (approximately 20%–50% of the revolutions) is reserved as a gas buffer or space for further separation of residual oil mist. This balanced design improves the separation efficiency of the oil-gas separator 2 under all operating conditions, reduces pressure drop, and enhances adaptability. Furthermore, this ratio range can be precisely achieved through additive manufacturing without additional assembly, demonstrating good process feasibility and performance repeatability.

[0057] In the process of realizing this application, it was also found that the helix angle of the cyclone plate 23 directly affects the flow velocity, centrifugal force intensity, and residence time of the oil-gas mixture in the spiral channel. If the helix angle is too small (e.g., less than 15°), the spiral channel is too gentle, the axial flow resistance of the oil-gas mixture increases, and the residence time is too long. Although this is beneficial for oil droplet settling, it will lead to a significant increase in pressure drop and easy formation of oil film accumulation in the channel, affecting continuous operation. If the helix angle is too large (e.g., greater than 45°), the channel is too steep, the circumferential velocity component of the oil-gas mixture decreases, the centrifugal force field intensity is insufficient, and fine oil droplets cannot be effectively thrown towards the inner wall of the shell 21, resulting in a decrease in separation efficiency.

[0058] According to an embodiment of this application, the helix angle of the swirl plate 23 is 15° to 45°.

[0059] For example, the helix angle of the swirl plate 23 can be any value among 15°, 20°, 25°, 30°, 35°, 40° and 45°.

[0060] In this embodiment, limiting the helix angle to the range of 15° to 45° ensures sufficient centrifugal force while controlling flow resistance within a reasonable range, achieving an optimized balance between separation efficiency and pressure drop. Secondly, this angle range is suitable for the air-fuel ratio and flow rate conditions under typical aero-engine operating conditions, exhibiting strong adaptability to various operating conditions. It can meet the low-resistance requirements under high flow rates while maintaining good separation performance under low flow rates. Furthermore, the helix angle of 15° to 45° results in a moderate axial length of the helical channel, facilitating matching with the height of the U-shaped housing 1. This promotes a compact, integrated design and allows for precise forming through additive manufacturing, achieving synergistic optimization between separation performance, flow characteristics, and structural compactness.

[0061] During the design process, the total number of spiral channels, cross-sectional shape (such as rectangular, trapezoidal or arc shape), and tilt angle of swirl plate 23 can be optimized according to the separation efficiency requirements to further improve the ability to capture fine oil droplets.

[0062] According to an embodiment of this application, along the flow direction of the oil-gas mixture, the separation channel located at the front end of the spiral channel is configured as a tapered structure to increase the circumferential velocity of the oil-gas mixture.

[0063] In this embodiment, the tapered structure causes the cross-sectional area of ​​the separation channel to gradually decrease along the flow direction. According to the continuity equation, the flow velocity of the oil-gas mixture increases accordingly, especially the circumferential velocity component. The higher circumferential velocity endows the oil-gas mixture with a stronger centrifugal inertial force before it enters the spiral channel, allowing the oil droplets to acquire greater radial ejection kinetic energy in the early stages of entering the spiral channel. This shortens the time required for the oil droplets to separate from the gas flow and improves the capture efficiency of fine oil droplets.

[0064] By pre-increasing the circumferential velocity through a tapered structure, the requirements for the centrifugal enhancement of the subsequent spiral channel can be appropriately reduced, allowing the spiral channel to maintain the same separation performance under lower swirling intensity, which is beneficial for reducing flow resistance and pressure drop.

[0065] In addition, the tapered structure itself has a smooth transition, without eddies or local abrupt changes, avoiding energy loss and secondary mixing of oil and gas caused by drastic speed changes. It can be applied to working conditions where the inlet speed of the oil-gas mixture is low or the flow rate fluctuates greatly, which can improve the separation stability of the oil-gas separator 2 at non-design points and achieve synergistic optimization of separation efficiency, pressure drop characteristics and working condition adaptability.

[0066] According to embodiments of this application, such as Figure 1 and Figure 2 As shown, the above-mentioned lubricating oil tank also includes a level gauge 3, which is installed in the tank body 1 and is suitable for detecting the level of oil in the cavity 11.

[0067] In this embodiment, by setting up a level gauge 3, the oil level in the lubricating oil tank can be displayed in real time and intuitively, so that ground maintenance personnel and crew members can promptly grasp whether the lubricating oil level is within the normal range. This avoids insufficient lubrication, accelerated wear, or even burnout accidents of engine bearings and gears due to low oil level, and also prevents abnormal pressure rise inside the oil tank or flooding of the exhaust port of the oil-gas separator 2 due to high oil level, thereby ensuring the safe operation of the lubricating oil system.

[0068] Continuous monitoring by the level gauge 3 can promptly detect abnormal lubricating oil consumption or leakage, providing important information for engine condition monitoring and fault diagnosis, and helping to implement condition-based maintenance and reduce operating costs.

[0069] According to the embodiments of this application, the level gauge 3 may be in different forms such as a glass level gauge, a magnetic float level gauge, or an electronic level sensor.

[0070] According to embodiments of this application, two mounting interfaces can be opened on the side wall of the housing 1 (e.g., one arm of the U-shaped structure or the bottom connecting area), corresponding to the upper and lower limits of the liquid level, respectively. The level gauge 3 is sealed and fixed to the housing 1 through a flange, threaded joint, or compression fitting, forming a measurement path communicating with the cavity 11. For the U-shaped housing 1, since the bottoms of the two arms are interconnected, the level gauge 3 can be installed on the outside of either arm, or, to more accurately reflect the overall liquid level, level gauges 3 can be installed on both arms for redundant monitoring. For electronic level sensors, they can be inserted into the cavity 11 through the opening at the top of the housing 1 or a single mounting hole on the side wall, using the sensor probe to directly contact the oil or measure the liquid level height non-contactly. This makes installation simpler and facilitates integration with the engine control system, enabling real-time acquisition and alarm of the liquid level signal.

[0071] According to embodiments of this application, such as Figure 2 As shown, the aforementioned oil tank also includes a filler port. The filler port is located at the other end of the tank body 1 and can be closed, allowing lubricating oil to be added into the cavity 11 when the tank is open.

[0072] The filler port is located at the other end of the housing 1 (i.e., the end away from the oil-gas separator 2) and can be sealed by the oil cap 4. This spatial separation from the oil-gas separator 2 avoids interference with the internal structure of the separator during the filling operation. At the same time, it ensures that the filling position is at an appropriate distance from the exhaust port of the oil-gas separator 2, preventing oil from directly impacting or splashing into the exhaust port 221 during the filling process and affecting the separation performance.

[0073] The filler neck uses a sealable cap 4 (such as a threaded cap, quick-opening cap, pressure filler connector, etc.), which can reliably seal after filling to prevent lubricating oil leakage and external contaminants (such as dust and moisture) from entering the cavity 11, ensuring the cleanliness of the lubricating oil and the safety of the system. At the same time, the sealed structure can also maintain the pressure balance between the inside of the oil tank and the outside (working in conjunction with the vent), avoiding oil splashing or evaporation loss when not filling.

[0074] The filler port is located at the other end of the housing 1, which facilitates ground maintenance and oil replenishment operations while the engine is in its entirety, without the need to disassemble surrounding parts, thus improving maintainability.

[0075] According to an embodiment of this application, the outlet position of the air outlet is higher than the designed highest oil level in the cavity 11.

[0076] The maximum design oil level refers to the maximum lubricating oil level that the oil tank can reach under specified operating conditions and design working conditions.

[0077] In this embodiment, the outlet is positioned above the highest oil level, which effectively prevents lubricating oil from flowing back into the exhaust pipe 22 when the engine is running normally, during maneuvering flight, or when the fuel tank is shaking. This avoids the gas passage after separation being blocked by oil, ensuring that the separated gas can be smoothly discharged through the exhaust port 221 and the outlet, thus maintaining the continuous and stable exhaust capacity of the oil-gas separator 2.

[0078] Since the exhaust port is always above the liquid level, even if the engine is under extreme conditions such as tilting, rolling or negative acceleration, the oil in the cavity 11 will not submerge the exhaust port, thus preventing the oil from being carried back into the exhaust system by the gas or causing exhaust pressure fluctuations, and avoiding the negative impact of secondary entrainment on separation efficiency.

[0079] In some other illustrative embodiments, the outlet position of the air outlet may be lower than or equal to the designed highest oil level in the cavity 11.

[0080] In such an embodiment, when the outlet position is lower than the designed maximum oil level, the lubricating oil in the cavity 11 will partially submerge the outlet under static or dynamic conditions, thereby forming a certain liquid seal effect. This can effectively prevent the separated gas (especially the gas containing trace amounts of oil mist) from directly diffusing in the reverse direction from the outlet to the environment outside the exhaust stack 22. This is suitable for occasions where there are strict restrictions on the concentration of gas emissions or the amount of leakage.

[0081] After the outlet is submerged in oil, the gas exchange between the inside of the exhaust pipe 22 and the cavity 11 mainly relies on the bubbling effect of the exhaust port 221. That is, the separated gas passes through the oil layer in the form of bubbles and is discharged. This process can further wash away the residual tiny oil droplets in the gas and improve the cleanliness of the finally discharged gas.

[0082] When the vent is at the same height as the highest designed oil level, the vent is located near the gas-liquid interface under normal liquid level. This ensures smooth gas discharge under most operating conditions and allows for a brief liquid seal to be formed when the oil sloshes or changes its orientation, thus balancing venting reliability and leak prevention performance.

[0083] Furthermore, when the exhaust port is allowed to be below or equal to the liquid level, the height space of the housing 1 can be fully utilized. The entire U-shaped cavity 11 (including the area originally located above the exhaust port) can be used to hold lubricating oil, thereby increasing the effective oil storage volume within the same housing 1 external dimensions. For aircraft engines, installation space is extremely limited, and every additional unit of effective volume helps to extend the lubricating oil change interval, improve engine endurance, or provide more sufficient oil reserves for cooling and lubrication.

[0084] According to another aspect of the embodiments of this application, an aircraft engine is provided. The aircraft engine includes an engine block and any of the aforementioned oil tanks. The oil tank is disposed in the engine block and is suitable for supplying lubricating oil to the engine block.

[0085] The U-shaped opening of the oil tank facing upwards can straddle or avoid the protruding parts of the engine core and accessory gearbox, allowing the oil tank to fit tightly with the engine block. This reduces the installation space occupied by the lubrication system outside the engine, which is beneficial for the overall miniaturization of the engine and the design of a high thrust-to-weight ratio.

[0086] The oil-gas separator 2 is integrally formed with the housing 1 and integrated into one end of the oil tank, avoiding the need for a separate separator and its connecting pipes, flanges and seals. This not only reduces weight, but also eliminates the risk of loose connections and leakage caused by vibration and thermal deformation, improving the reliability and safety of the whole machine in long-term operation.

[0087] The high-efficiency spiral channel oil-gas separator 2 built into the oil tank uses centrifugal force to quickly separate the gas in the return oil, ensuring that the lubricating oil supplied to the engine bearings and gears has a low gas content, improving the lubrication and cooling effect, and extending the service life of key components.

[0088] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this application is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this application, and all such substitutions and modifications should fall within the scope of this application.

Claims

1. A lubricating oil tank for an aircraft engine, characterized in that, include: The box is constructed as a U-shaped structure with the opening facing upwards, forming a U-shaped cavity inside; An oil-gas separator, integrally formed with the housing at one end of the housing, and comprising: The housing has an internal separation channel that connects the cavity and the oil return system of the aircraft engine; An exhaust pipe with an outlet at one end is disposed within the separation channel, and the outlet is connected to the cavity; A swirl plate is configured in a helical shape and surrounds between the exhaust stack and the housing to form a helical channel; The exhaust stack has multiple exhaust holes that connect the spiral channel and the exhaust port. After the oil-gas mixture from the oil return system enters the spiral channel, the oil droplets in the oil-gas mixture are thrown towards the inner wall of the shell and flow into the cavity under the action of centrifugal force. The gas in the oil-gas mixture is discharged through the exhaust holes and the exhaust port.

2. The lubricating oil tank according to claim 1, characterized in that, The diameter of the spiral channel gradually decreases or increases along the flow direction of the oil-gas mixture.

3. The lubricating oil tank according to claim 1, characterized in that, The plurality of exhaust holes are arranged in a spiral shape in the middle of the spiral channel, along the extension direction of the spiral channel.

4. The lubricating oil tank according to claim 3, characterized in that, The number of turns of the plurality of exhaust holes is 50% to 80% of the total number of turns of the spiral channel.

5. The lubricating oil tank according to claim 1, characterized in that, The spiral angle of the swirl plate is 15° to 45°.

6. The lubricating oil tank according to any one of claims 1-5, characterized in that, Along the flow direction of the oil-gas mixture, the separation channel located at the front end of the spiral channel is configured as a tapered structure to increase the circumferential velocity of the oil-gas mixture.

7. The lubricating oil tank according to claim 1, characterized in that, Also includes: A level gauge, installed in the housing, is used to detect the level of oil in the cavity.

8. The lubricating oil tank according to claim 1, characterized in that, Also includes: The oil filling port can be sealed at the other end of the housing, and is suitable for adding lubricating oil into the cavity when the housing is open.

9. The lubricating oil tank according to claim 1, characterized in that, The outlet of the air vent is positioned above the designed maximum oil level within the cavity.

10. An aircraft engine, characterized in that, include: Engine block; The oil tank as described in any one of claims 1-9 is disposed in the engine block and is suitable for providing lubricating oil to the engine block.

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