Oil-gas separation device for ventilation outlet of bearing cavity and implementation method of oil-gas separation device

Abstract

The invention relates to the technical field of oil-gas separation, in particular to a bearing cavity ventilation outlet oil-gas separation device and method. The device comprises a pipe body, a spiral rotary wall body fixedly connected to the lower end of the pipe body and provided with an opening guide, grids on the wall body and a blocking part structure connected with the grids, and the outer wall face of the wall body is provided with a super-oleophobic coating. After installation, the outer surface of the wall body and the inner wall face of the bearing cavity form an oil blocking structure. Through shielding of a flowing oil film and splashing oil drops on the wall surface of a bearing cavity, oleophobic combination of gravity and grid filtering separation of an oil-gas mixture and combined separation of rotating centrifugal force and gravity of the oil-gas mixture guided into the device, lubricating oil flows back to the bearing cavity, the oil content of a ventilation outlet is reduced, it is guaranteed that gas is smoothly exhausted, and blockage is avoided.

Description

Technical Field

[0001] This invention relates to the field of oil-gas separation technology, and more specifically to an oil-gas separation device for a bearing cavity ventilation outlet and its implementation method. Background Technology

[0002] As the core power unit of aircraft, the bearing lubrication of aero-engines is a crucial link in ensuring the long-term reliable operation of the entire engine, maintaining the stability of the lubrication and heat dissipation system, and meeting the stringent standards of the aerospace field. In addition to fulfilling the lubrication and cooling functions of bearings / gears, the bearing cavity, located in a high-temperature environment, has a structural characteristic of expelling oil and gas through the bearing cavity ventilation pipes. With the increasing demand for reducing lubricating oil consumption, the oil and gas discharged from the bearing cavity ventilation outlet must have an extremely low oil content. This invention designs an oil and gas separation device for the ventilation outlet of an aero-engine bearing cavity, which can achieve efficient separation of the oil and gas mixture in the bearing cavity, effectively reducing the oil content in the exhaust and preventing exhaust pipe blockage.

[0003] Currently, oil-gas separation technologies in the industry are mainly divided into two categories: passive and active. Passive separation technology relies on the fluid's own characteristics or a fixed flow channel structure, while active technology requires external power input. Existing filter-type separation devices have many technical bottlenecks: some devices rely solely on the filter screen to intercept oil droplets, lacking power assistance, resulting in high gas flow resistance, low separation efficiency, and difficulty in adapting to high-speed operating conditions; in some separation structures, oil droplets easily adhere to the filter screen surface after being intercepted, not only affecting gas adhesion to the rising channel but also easily causing filter screen blockage, leading to a continuous decline in separation efficiency; in addition, the gas and oil separation driving force in traditional separation devices is singular, often resulting in incomplete separation and gas carrying oil mist, failing to meet the requirements of high-precision separation. At the same time, the lubricating oil used in aero-engines has specific viscosity-temperature characteristics, and oil droplets easily adhere to the filter screen surface after being intercepted, not only seriously affecting the gas flow in the exhaust pipe but also easily causing filter screen blockage, leading to a continuous decline in separation efficiency, which in turn affects the normal lubrication and heat dissipation of the bearing cavity, directly threatening the operational safety of aero-engines. Currently, few oil-gas separation devices meet these requirements. To address the aforementioned issues, this invention proposes a bearing cavity oil-gas separation device structure that combines the principles of oil film shielding, dynamic centrifugation, filtration, and surface oleophobicity. It also provides a bearing cavity ventilation outlet oil-gas separation device, achieving efficient oil-gas separation while preventing oil adhesion and blockage, thus ensuring long-term stable operation of the device. Summary of the Invention

[0004] This invention provides an oil-gas separation device for the ventilation outlet of a bearing cavity. The purpose is to utilize a shielding structure in the oil film flow direction, an eccentric rotating flow channel combining dynamic pressure centrifugal force and gravity in the oil flow direction, and a grid structure with a filter and anti-adhesion coating to form a synergistic effect, thereby comprehensively reducing the oil content of the oil-gas discharged from the ventilation outlet of the bearing cavity, while avoiding oil adhesion and blockage, and ensuring smooth gas discharge.

[0005] The above objectives are achieved through the following technical solutions:

[0006] An oil-gas separation device for a bearing cavity ventilation outlet includes: a pipe body, a wall body fixed to the lower end of the pipe body, and a stop portion fixed to the lower end of the wall body; the wall body is an open spiral rotating body, having a first edge radially close to the axis and a second edge radially away from the axis, with a main inlet formed between the outer wall surface of the first edge and the inner wall surface of the second edge, and a guide structure provided on the main inlet; the wall body is provided with a grid distributed along its own spiral wall and radiating outward from the axis of the pipe body; when the bearing cavity ventilation outlet oil-gas separation device is installed in the bearing cavity, an oil-blocking film structure is formed between the grid and the inner wall surface of the bearing cavity; a super oleophobic coating is provided on the outer wall surface of the wall body.

[0007] After the bearing cavity ventilation outlet oil-gas separator is installed between the bearing cavity and the ventilation pipeline, the height h of the oil-gas separator and the inner wall of the bearing cavity forming an oil-blocking film structure is 3~5mm.

[0008] The pipe body has an inner cylindrical surface and is coaxially arranged with the ventilation duct.

[0009] Half of the spiral section of the wall is coaxial with the tube, and the other half of the spiral section of the wall is eccentric to the axis of the tube, with an eccentricity of e.

[0010] Relationship between e and inner diameter of pipe body 1: When the inner diameter of pipe body 1 is 10mm, e is 1~1.5mm, the main inlet opening L0 is 1.8mm, and the adjacent wall is 13.5~12.5mm; when the inner diameter D1 of pipe body 1 is 20mm, the eccentricity e is 2~3mm.

[0011] The minimum length of the spiral rotating body is greater than the length of the main inlet opening L0, and is also greater than the sum of the height h of the oil baffle structure and the thickness of the baffle 3.

[0012] The main inlet opening L0 is determined by the oil and gas volumetric flow rate. When the oil and gas volumetric flow rate is 2*10 -5 m 3 / s, with the main inlet opening L0 taken as 1.8~3mm; when the oil and gas volumetric flow rate is 5*10 -5 m 3 / s, the main inlet opening L0 is 4~6mm.

[0013] The spacing between any two adjacent grids shall not be less than 0.8 mm, and the number of grids shall be 10 to 30; reduce the number of grids by 1 to 2 at the main inlet.

[0014] The baffle is coaxially arranged with the tube body and is closest to the bearing cavity drive shaft, used to shield lubricating oil splashed radially from the bearing cavity drive shaft.

[0015] The wall was obtained by 3D printing using Al powder as the raw material.

[0016] The grid runs through the barrier.

[0017] A method for implementing a bearing cavity ventilation outlet oil-gas separation device includes the following steps:

[0018] Step 1: During implementation, the oil-gas separation device at the bearing cavity ventilation outlet is installed between the bearing cavity and the ventilation pipeline;

[0019] Step 2: The inner wall of the bearing cavity housing is a cylindrical wall, and the grid is located on the inner side of the cylindrical wall, so that the distance between the cylindrical wall of the bearing cavity and the top of the grid is 3~5mm;

[0020] Step 3: The opening direction of the main inlet is set directly opposite to the direction of rotation of the oil film on the cylindrical wall of the bearing cavity.

[0021] Compared with the prior art, the beneficial effects of the bearing cavity ventilation outlet oil-gas separation device of the present invention are as follows:

[0022] This invention addresses the core need to reduce the oil content of the oil and gas discharged from the bearing cavity ventilation outlet. An oil-gas separation device is designed and added to the bearing cavity ventilation outlet. This device is integrally formed using Al powder 3D printing, resulting in low cost, short processing cycle, and low weight. The device surface is coated with a superoleophobic coating prepared by spraying and dip coating processes. This coating not only possesses excellent oil-repellent / oil-resistant properties and Class 1 substrate adhesion, but also achieves wide temperature range resistance and impact resistance from -40℃ to 190℃, effectively reducing oil residue on the device surface and making it suitable for the harsh operating environments in the aerospace field.

[0023] In terms of core performance and scenario adaptation, the coating's oleophobic properties are precisely matched to applications in aviation separation devices such as oil tanks. Its superior oleophobic effect directly improves oil-gas separation efficiency, overcoming the bottleneck in separation performance caused by oil residue in traditional devices. Simultaneously, through structural design and process optimization, it achieves a synergistic upgrade in environmental tolerance and mechanical performance, enabling stable operation in extreme temperature ranges and complex conditions, ensuring the reliability of the device.

[0024] In terms of preparation and application costs, the technology has significant advantages for practical application: the preparation process is mature and controllable, the process is simple and easy to operate, the required materials are readily available and meet environmental protection requirements, which can reduce the difficulty and cost of large-scale production; the coating itself has extremely strong stability, the performance decays slowly over long-term use, and the storage conditions are relaxed, requiring no special protection, which greatly reduces the overall cost of use and storage, balancing performance and economy.

[0025] It is suitable for the efficient separation of oil-gas mixtures in fields such as power machinery, aerospace, and industrial fluid processing, and is especially suitable for oil-gas separation scenarios under high-speed rotation conditions in the bearing cavity of aero engines. Attached Figure Description

[0026] Figure 1 A three-dimensional view of the bearing cavity ventilation outlet oil-gas separation device of the present invention is shown. Figure 1 ;

[0027] Figure 2 Showing Figure 1 Enlarged view of point A in the middle;

[0028] Figure 3 Three-dimensional bearing cavity ventilation outlet oil-gas separation device Figure 2 ;

[0029] Figure 4 The comparison of oil content in each sample after the corresponding working time is shown.

[0030] Figure 5 This shows a cross-sectional view of the structure in which the oil-gas separator is installed between the bearing housing and the ventilation duct.

[0031] In the figure: 1. Pipe body; 2. Wall; 21. First edge; 22. Second edge; 3. Baffle. Detailed Implementation

[0032] A bearing cavity ventilation outlet oil-gas separation device, see below. Figures 1 to 3 It includes: a pipe body 1, a wall body 2 fixed to the lower part of the pipe body 1, and a baffle 3 fixed to the lower part of the wall body 2.

[0033] The inner wall surface of tube 1 is a smooth rotating surface, such as a smooth cylindrical surface, and the axis of tube 1 refers to the axis of its own inner cylindrical surface.

[0034] Wall 2 is a hollowed-out spiral rotating body, with a spiral channel formed on its inner wall surface. The cross-section of wall 2 perpendicular to the axis of tube 1 has an inner diameter D2 of half of the cross-section. Figure 5 The A-view) is coaxially set with tube body 1, and the inner diameter of the other half of the cross section is D3 ( Figure 5The wall 2 (view from direction A) is eccentrically positioned relative to the axis of pipe 1. A larger eccentricity e increases the hydrodynamic centrifugal force, thus improving oil-gas separation. Around the circumference of wall 2, each grid serves as an oil-gas inlet. However, due to the small grid gaps and the discharge of hydrodynamic oil-gas separated liquid, the grid's role as an oil-gas inlet is negligible. The position of the eccentricity e between wall 2 and the axis of pipe 1 forms the main oil-gas inlet, i.e. Figure 2 A space is formed along the axis of the pipe body 1 between the outer wall surface of the first edge 21 and the inner wall surface of the second edge 22 of the middle wall. Oil and gas with initial velocity enter from the main inlet, creating initial dynamic pressure. This creates centrifugal force relative to the axis of the pipe body 1 along the inner wall surface of the wall body 2 at a partial eccentricity e. Due to the density difference between the oil and gas, the denser lubricating oil is moved by centrifugal force to the inner wall surface of the wall body 2, and then flows back into the bearing cavity along the grid confluence. Main inlet direction ( Figure 5 View A, opening L0), and the direction of rotation of the drive shaft at the center of the bearing cavity ( Figure 5 Hollow arrows (relative to each other) determine the design direction of the eccentricity ( Figure 5 (View from A).

[0035] The structural dimensions and their ranges are as follows:

[0036] 1. After the oil-gas separator is installed in the bearing cavity, the main inlet length L2 of the spiral structure protrudes relative to the inner wall of the bearing cavity. Figure 5 (BB view), where the length h between the grid and the inner wall of the bearing cavity is the baffle oil film structure, which is used to block the lubricating oil flowing along the bearing cavity wall from entering the oil-gas separation device. It has the greatest effect on reducing the oil content at the bearing cavity ventilation outlet. Experiments show that increasing the baffle oil film structure h can reduce the oil content at the ventilation outlet by 20% to 30%, and is taken as 3 to 5 mm.

[0037] 2. The baffle 3 is connected to the wall 2 and located at the lower end of the wall 2. After installation, it is closest to the drive shaft of the bearing cavity and is used to shield the lubricating oil splashed radially from the drive shaft. The diameter D4 and its extended grid are used together for shielding. Its size is not required under the premise of ensuring structural strength. It plays a role in reducing the oil content of the bearing cavity ventilation outlet second only to the length h. It can generally reduce the oil content of the ventilation outlet by 2% to 5%.

[0038] 3. A super oleophobic coating is added to the outer wall surface of wall 2. When oil and gas encounter the coating, the residence time of lubricating oil on the wall surface is reduced, thus reducing the amount of lubricating oil entering the spiral.

[0039] 4. The thickness δ of wall 2 ( Figure 5 (View from direction A) requires that the outer surface coating processing strength be guaranteed, generally 0.8~1mm;

[0040] 5. Main inlet opening L0 and main inlet length L2 of wall 2 ( Figure 5(BB view), together they are used to increase the initial velocity of oil and gas entering wall 2, thereby increasing dynamic pressure and centrifugal force. Among them, the main inlet opening L0 has a greater effect, which is determined by the oil and gas volume flow rate. When the oil and gas volume flow rate is 2*10 -5 m 3 / s, with the main inlet opening L0 taken as 1.8~3mm; when the oil and gas volumetric flow rate is 5*10 -5 m 3 / s, the main inlet opening L0 is 4~6mm.

[0041] 6. The main inlet length L2 should not interfere with the radial space of the bearing cavity. Its maximum value is limited by structural strength, and its minimum value should be greater than the main inlet opening length L0. It should also be greater than the sum of the oil film height h on the bearing cavity wall of the second wall and the thickness of the third wall. To be suitable for working conditions with a high oil content in the bearing cavity, the discharge of lubricating oil in the spiral of the second wall is a key design factor. The main inlet length L should be lengthened and the grid opening width should be increased. At the same time, the resistance loss of the oil-gas flow and oil-gas separation device should be reduced. Generally, the main inlet length L2 is more than 1.5 times the inner diameter D2.

[0042] 7. The eccentricity e is limited by the inner diameter D1 of pipe body 1. Simultaneously, it, along with the main inlet opening L0, determines the inner diameter D2 of half the cross-section of wall body 2. When the inner diameter D1 of pipe body 1 is 10mm, the eccentricity e is 1~1.5mm, the main inlet opening L0 is 1.8mm, and the inner diameter D2 is 13.5~12.5mm. When the inner diameter D1 of pipe body 1 is 20mm, the eccentricity e is 2~3mm.

[0043] 8. The main inlet guide structure is characterized by length L1 and angle α. The guide structure is tangent to the inner diameter D3 as much as possible to guide the flow of oil and gas into the spiral.

[0044] 9. The grids on wall 2 are evenly distributed radially relative to the axis of pipe 1. For the oil and gas swirling within the bearing cavity driven by the drive shaft, the grids act as a filter. For the lubricating oil separated within the spiral of wall 2, the grids serve as the oil outlet. The grid spacing should not be too small, as this will affect structural strength and processing; generally, it should not be less than 0.8 mm. The number of grids can be 10-30. One or two grids should be reduced at the main inlet to avoid affecting the inlet guiding function.

[0045] A method for implementing an oil-gas separation device at the ventilation outlet of a bearing cavity:

[0046] Step 1: During implementation, the oil-gas separator is installed between the bearing cavity and the ventilation pipe.

[0047] Step 2: The inner wall of the bearing cavity housing is a cylindrical wall, and the grid is located on the inner side of the cylindrical wall, so that the distance between the cylindrical wall of the bearing cavity and the wall without grid is 3~5mm;

[0048] Step 3: The main inlet opening of the oil-gas separator is set in the direction directly opposite to the rotation direction of the oil film on the cylindrical wall of the bearing cavity.

[0049] Working principle:

[0050] The high-temperature lubricating oil and oil-gas inside the bearing cavity after cooling and lubrication mainly exhibit three types of fluid flow states: continuously flowing lubricating liquid on the inner wall of the bearing cavity, swirling oil-gas mixture between the drive shaft and the inner wall of the bearing cavity, and lubricating oil droplets splashed from the drive shaft surface onto the bearing cavity wall. When these fluids encounter the oil-gas separation device of this invention, they are deflected back, separated into oil and gas, and fall back into the bearing cavity, thus reducing the oil content at the bearing cavity ventilation outlet.

[0051] 1. By using the blocking principle, on the one hand, the oil film structure h formed by the oil-gas separator and the inner wall of the bearing cavity blocks the continuous flow of lubricating oil on the inner wall of the bearing cavity; on the other hand, the baffle 3 of the oil-gas separator blocks the lubricating oil droplets splashed from the surface of the drive shaft onto the wall of the bearing cavity, preventing them from entering the ventilation outlet of the bearing cavity.

[0052] 2. Superoleophobic principle: When the swirling oil-gas mixture between the bearing cavity drive shaft and the inner wall of the bearing cavity flows to the superoleophobic coating surface on the outer surface of the wall 2 of the oil-gas separator, a small portion of the oil droplets adhere to the reduced surface area and thus their residence time, quickly falling back into the bearing cavity and preventing them from entering the bearing cavity ventilation outlet. The superoleophobic coating's characteristic of reducing contact angle hysteresis lowers the friction between the oil and the surface of wall 2 to an extremely low level (friction coefficient ≤ 0.02), significantly reducing oil flow resistance. Simultaneously, the effects of the superoleophobic coating are amplified under the influence of gravity and centrifugal force.

[0053] 3. Filtration principle: When the swirling oil-gas mixture between the bearing cavity drive shaft and the inner wall of the bearing cavity flows to the outer surface of the wall 2 of the oil-gas separator, a small portion of the oil droplets are blocked by the grid and come into contact with the structural wall surface, are filtered down and fall back into the bearing cavity, preventing them from entering the bearing cavity ventilation outlet.

[0054] 4. Dynamic pressure separation principle: When the swirling oil-gas mixture between the bearing cavity drive shaft and the inner wall of the bearing cavity flows into the main inlet L0 of the oil-gas separator, it has an initial velocity, i.e., dynamic pressure. Under the guidance of the eccentricity e wall, the dynamic pressure is converted into centrifugal force. The oil-gas mixture is subjected to the combined action of centrifugal force and gravity. The denser lubricating oil (relative to the axis of pipe 1 and the exhaust direction) moves outward and downward to the spiral wall of the oil-gas separator and is discharged from the grid to the outside of the oil-gas separator, falling back into the bearing cavity and preventing it from entering the bearing cavity ventilation outlet; the less dense air gathers inward to form a certain high pressure and is discharged to the low-pressure outlet of the ventilation pipe.

[0055] The above-mentioned method for preparing superoleophobic coatings, Example 1, includes the following steps:

[0056] S1. Mix polydimethylsiloxane (PDMS) and curing agent thoroughly at a mass ratio of 10:1, then add ethyl acetate and dilute with PDMS at a ratio of 4:1 to obtain a stable PDMS mixed adhesive solution.

[0057] S2. Hydrophilic fumed silica nanoparticles and fluorinated surfactant FS-50 are mixed in anhydrous ethanol at a ratio of 0.1g:1ml:50ml. The mixture is then magnetically stirred at 300r / min for 1 minute to obtain a super oleophobic spray coating.

[0058] S3. Apply the PDMS mixed adhesive solution evenly to the pretreated substrate surface using a spraying method. Use a 0.3mm spray gun with spraying pressure of 2 bar, spraying distance of 20 cm, and spraying time of 3 min. Allow the solution to stand to evaporate and form a PDMS coating.

[0059] S4. The super oleophobic spray liquid is deposited on the PDMS coating surface by spraying process. A 0.5mm spray gun is used, and the spraying pressure is controlled at 2 bar, the spraying distance is 20cm, and the spraying time is 3min.

[0060] S5. Place the deposited substrate in a 120°C environment for 2 hours to heat-treat and cure the coating to form a superoleophobic coating.

[0061] Example 2 includes the following steps:

[0062] S1. Mix polydimethylsiloxane (PDMS) and curing agent thoroughly at a mass ratio of 20:1, then add ethyl acetate and dilute with PDMS at a ratio of 4:1 to obtain a stable PDMS mixed adhesive solution.

[0063] S2. Hydrophilic fumed silica nanoparticles and fluorinated surfactant FS-50 are mixed in anhydrous ethanol at a ratio of 0.1g:1ml:50ml. The mixture is then magnetically stirred at 300r / min for 1 minute to obtain a super oleophobic spray coating.

[0064] S3. Apply the PDMS mixed adhesive solution evenly to the pretreated substrate surface using a spraying method. Use a 0.3mm spray gun with spraying pressure of 2 bar, spraying distance of 20 cm, and spraying time of 3 min. Allow the solution to stand to evaporate and form a PDMS coating.

[0065] S4. The super oleophobic spray liquid is deposited on the PDMS coating surface by spraying process. A 0.5mm spray gun is used, and the spraying pressure is controlled at 2 bar, the spraying distance is 20cm, and the spraying time is 3min.

[0066] S5. Place the deposited substrate in a 120°C environment for 2 hours to heat-treat and cure the coating to form a superoleophobic coating.

[0067] Example 3: The grid unit surface of the wall is uncoated.

[0068] Compared with Example 1, Comparative Example 1 prepared a superoleophobic coating. The coating on the inner and outer surfaces of the lattice unit was prepared using a superoleophobic coating preparation method, which included the following steps:

[0069] A1. A uniform and stable dispersion was prepared by dispersing 0.1g of fumed silica nanoparticles (specific surface area of ​​300m2 / g) in 10g of TrisHCl buffer solution through magnetic stirring and ultrasonic dispersion. Dopamine hydrochloride was added to prepare a composite dispersion with a dopamine hydrochloride concentration of 0.5mg / mL.

[0070] A2. Stir the above dispersion magnetically while it is connected to the atmosphere, and react for 24 hours to polymerize dopamine into polydopamine.

[0071] A3, according to 60μL / cm 2 The amount of the dispersion was applied to the glass surface, and then freeze-dried after freezing at -80°C.

[0072] A4. Subsequently, the coating underwent a two-step CVD treatment: First, CVD treatment was carried out at 25°C with 1 mL of aminopropyltriethoxysilane for 24 hours; Second, CVD treatment was carried out at 25°C with 300 μL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane for 24 hours, finally obtaining a superoleophobic coating.

[0073] The substrates in Examples 1 to 3 and the comparative examples were: Al powder 3D printing substrates were sanded 30 times with 800-grit sandpaper at 50N pressure, and then ultrasonically cleaned with deionized water for 3 minutes, ultrasonically cleaned with anhydrous ethanol for 3 minutes, and dried with hot air at 50°C to obtain the substrates.

[0074] The coatings prepared in Examples 1, 2, 3 and Comparative Example 1 were used in a bearing cavity oil-gas separator for performance testing. The inlet flow rate was 60 L / min, the oil-gas ratio was 1:1, and the bearing speed was 3000 r / min. The oil content at the exhaust port was counted to evaluate the oil-gas separation effect; the lower the oil content, the better the separation effect.

[0075] The coating prepared in Comparative Example 1 lost its self-desorption function for oil stains and exhibited hydrophilic and oleophilic characteristics. Its oil content in the device per unit time was higher than that in Examples 1, 2, and 3. Figure 4 As shown.

[0076] This superoleophobic coating exhibits significant advantages under harsh conditions of high temperature, high pressure, and high speed oil flow. Even after long-term use at 120℃, it shows no thermal deformation or coating separation issues, far exceeding the thermal stability of common superoleophobic coatings in Comparative Example 1. Facing working pressures of 50kPa~250kPa and inlet flow rates of no less than 60L / min, the coating, with its Class 1 substrate adhesion and low coefficient of friction ≤0.02, is not damaged by high-speed impacts, nor does it exhibit the oil contact angle reduction or pinning adhesion phenomena seen in Comparative Example 1. It consistently maintains excellent oleophobic properties with an oil contact angle >150° and an oil contact angle hysteresis <5°. Under high pressure and high-speed flow, the oil can quickly detach from the coating surface. Combined with the synergistic effect of centrifugal force and gravity, it can efficiently pass through the grid for separation, completely preventing oil adsorption and grid blockage. Furthermore, it can adapt to high-speed rotating flow scenarios of lubricating oil-gas mixtures without additional power, significantly improving service life and stability under complex operating conditions. Example 1 yields a metal coating with excellent performance and oleophobic effect, which can effectively reduce oil residue on the inner wall of the device and is suitable for harsh aviation environments.

Claims

1. A bearing cavity ventilation outlet oil-gas separation device, characterized in that, include: The tube body, the wall body fixed to the lower end of the tube body, and the stop body fixed to the lower end of the wall body; the wall body is an open spiral rotating body, the wall body has a first edge radially close to the axis and a second edge radially away from the axis, the outer wall surface of the first edge and the inner wall surface of the second edge form a main inlet, and a guide structure is provided on the main inlet; the wall body is provided with grids distributed along its own spiral wall and radiating outward from the axis of the tube body; after being installed in the bearing cavity, the outer wall surface between the top of the grid of the bearing cavity ventilation outlet oil-gas separation device and the inner wall surface of the bearing cavity forms an oil-blocking film structure; a super oleophobic coating is provided on the outer wall surface of the wall body.

2. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, After the bearing cavity ventilation outlet oil-gas separator is installed between the bearing cavity and the ventilation pipeline, the height h of the oil-gas separator and the inner wall of the bearing cavity forming an oil-blocking film structure is 3~5mm.

3. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The pipe body has an inner cylindrical surface and is coaxially arranged with the ventilation duct.

4. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, Half of the spiral section of the wall is coaxial with the tube, and the other half of the spiral section of the wall is eccentric to the axis of the tube, with an eccentricity of e. When the inner diameter of pipe body 1 is 10mm, e is taken as 1~1.5mm, the main inlet opening L0 is equal to 1.8mm, and the adjacent wall is taken as 13.5~12.5mm; when the inner diameter D1 of pipe body 1 is 20mm, the eccentricity e is taken as 2~3mm. The minimum length of the spiral rotating body is greater than the length of the main inlet opening L0, and is also greater than the sum of the height h of the oil baffle structure and the thickness of the baffle 3.

5. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The main inlet opening L0 is determined by the oil and gas volumetric flow rate. When the oil and gas volumetric flow rate is 2*10 -5 m 3 / s, with the main inlet opening L0 taken as 1.8~3mm; when the oil and gas volumetric flow rate is 5*10 -5 m 3 / s, the main inlet opening L0 is 4~6mm.

6. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The spacing between any two adjacent grids shall not be less than 0.8 mm, and the number of grids shall be 10 to 30; reduce the number of grids by 1 to 2 at the main inlet.

7. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The baffle is coaxially arranged with the tube body and is closest to the bearing cavity drive shaft, used to shield lubricating oil splashed radially from the bearing cavity drive shaft.

8. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The wall was obtained by 3D printing using Al powder as the raw material.

9. The bearing cavity ventilation outlet oil-gas separation device according to claim 1, characterized in that, The grid runs through the barrier.

10. A method for implementing an oil-gas separation device at the ventilation outlet of a bearing cavity, characterized in that, Includes the following steps: Step 1: During implementation, the oil-gas separation device at the bearing cavity ventilation outlet is installed between the bearing cavity and the ventilation pipeline; Step 2: The inner wall of the bearing cavity housing is a cylindrical wall, and the grid is located on the inner side of the cylindrical wall, so that the distance between the cylindrical wall of the bearing cavity and the top of the grid is 3~5mm; Step 3: The opening direction of the main inlet is set directly opposite to the direction of rotation of the oil film on the cylindrical wall of the bearing cavity.

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