Novel multifunctional integrated lubricating oil tank for micro turbojet engine

Abstract

The invention discloses a novel multifunctional integrated lubricating oil tank for a micro turbojet engine, and belongs to the technical field of lubricating oil tanks of micro turbojet engines. Comprising a lubricating oil tank body, a heat exchange assembly and a filtering assembly, the lubricating oil tank body is used for storing lubricating oil, and the heat exchange assembly and the filtering assembly are both arranged in the lubricating oil tank body and fixedly connected; a supporting column is arranged in the lubricating oil tank body and used for supporting the inner wall of the lubricating oil tank body. An integrated design scheme is provided for the lubricating oil system, all functions of the lubricating oil system are integrated on the circulating lubricating oil tank, the space occupancy rate of the structure of the lubricating oil system is reduced through the design, maintenance of the lubricating oil system is facilitated, and the stability and reliability of the lubricating oil system are improved.

Description

Technical Field

[0001] The invention relates to the technical field of micro turbojet engine lubricating oil tanks, in particular to a novel multifunctional integrated lubricating oil tank for a micro turbojet engine. Background Art

[0002] The power transmission system in turbojet engines is still based on mechanical transmission, and its working reliability depends largely on the quality of the lubrication system. The basic function of the lubrication system is to supply lubricating oil to the engine to reduce the friction and wear of the moving dual surfaces, prevent them from corrosion and surface hardening, transfer the heat generated by friction and the heat transferred to the lubricating oil by high-temperature parts, and remove the hard inclusions formed between the dual surfaces.

[0003] As an important accessory of the lubricating oil system, the oil tank is used to store oil, dissipate the heat of the lubricating oil, precipitate impurities in the lubricating oil, separate the air in the lubricating oil, and ensure the recycling of the engine lubricating oil.

[0004] At present, most of the lubricating oil systems used in the market are only used for engine ground test, and all functional components are set outside the lubricating oil tank for operation. There are problems such as long pipelines, complex structure, heavy weight, poor reliability, etc., and the original lubricating oil tank body structure is a thin-walled sheet metal welding structure, and the overall rigidity and stability of the lubricating oil tank body are poor. The above problems will make it difficult for the lubricating oil tank to withstand the high load and complex environment in the engine flight test.

[0005] Based on this, how to design a set of lubricating oil tanks suitable for engine flight tests is an issue that we urgently need to solve. Summary of the invention

[0006] The object of the present invention is to provide a new multifunctional integrated oil tank for a micro turbojet engine, including an oil tank body. By arranging support columns in the oil tank body and integrating various functional components in a closed oil tank body surrounded by the oil tank body, the oil tank body can withstand the high load and complex environment in the engine flight test.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions:

[0008] A novel multifunctional integrated oil tank for a micro turbojet engine comprises an oil tank body, a heat exchange component and a filter component, wherein the oil tank body is used to store oil, and the heat exchange component and the filter component are both arranged in the oil tank body and fixedly connected;

[0009] A support column is provided inside the lubricating oil box body, and the support column is used to support the inner wall of the lubricating oil box body.

[0010] In the prior art, all functional components of the oil tank are arranged outside the oil tank, and the connecting pipes are long and numerous, which makes the oil tank structure complex and heavy. In the engine flight test, it may reduce the power output or increase the fuel consumption, and increase the risk of failure. At the same time, due to the poor overall rigidity of the oil tank, the oil tank may be deformed, cracked or leaked, which may lead to safety risks and is difficult to meet the performance requirements of the engine flight test for the oil tank.

[0011] Specifically, a cavity for containing lubricating oil is provided inside the lubricating oil box, and the box body of the lubricating oil box is the outer shell of the lubricating oil cavity. The present application improves the volume, weight, rigidity and function of the lubricating oil box described in the present application by integrating a plurality of functional components inside the lubricating oil box for storing lubricating oil and arranging a support column inside the lubricating oil box, reducing the arrangement of connecting parts such as connecting pipes and strengthening the structural strength of the lubricating oil box, so as to be suitable for both ground test and flight test of the engine.

[0012] It includes a lubricating oil box, a heat exchange component and a filter component. The heat exchange component is used to cool the lubricating oil, and the filter component is used to filter the lubricating oil. Finally, the treated lubricating oil is pumped out to the engine again for reuse.

[0013] Compared with the prior art, the complex structure of several connecting pipelines and boxes not only increases the difficulty of installation and maintenance, but also may lead to increased fluid resistance, affect the efficiency of the lubricating oil system, and increase the slippage of the connection points and the failure rate in the lubricating oil system circuit. The interior of the lubricating oil box of the present invention not only stores lubricating oil, but also accommodates several functional components, which can effectively reduce the length and / or number of connecting pipes. As a result, the space in the lubricating oil box is effectively utilized, and the overall volume and weight are reduced to meet the requirements of micro-turbojet engines and micro-aircraft for the mass and volume of lubricating oil boxes. At the same time, due to the simple overall structure, the number of points where the system fails is reduced and it is convenient for later maintenance.

[0014] Support columns are provided inside the oil box, which can, on the one hand, reinforce the oil box and improve its overall stiffness, load-bearing capacity and anti-deformation ability. The inner wall of the oil box is used to support and constrain the oil box. When the inside and outside of the oil box are affected by air pressure, external loads, etc., the support columns can effectively disperse the external loads to the entire box structure. This reduces the concentration of local stress and reduces deformation or damage caused by excessive stress. The support columns can be reasonably arranged and connected so that each support column can bear a certain load, thereby avoiding deformation of the box caused by excessive force at a single point. On the other hand, when the vibration of the engine is transmitted to the oil box, the vibration may cause the connection between the oil box and the internal functional components or the connection points itself to loosen, resulting in problems such as oil leakage. After the various functional components are arranged inside the oil tank, the support columns provide support and installation points for the functional components inside the oil tank. Compared with the prior art that uses pipelines to connect the various functional components, this solution can directly fix the functional components on the inner wall of the oil tank and strengthen the connection strength and / or fixing points, thereby improving the stability of the connection points, preventing the connection failure of the oil tank and the internal functional components due to aircraft vibration, and allowing the overall structure of the oil tank to better adapt to the shaking and take-off and landing of the aircraft during test flight.

[0015] Furthermore, the oil tank body is a ring body, the inner side of the ring body is the inner wall of the oil tank, the outer side of the ring body is the outer wall of the oil tank, the inner wall of the oil tank is connected to the engine, and the outer wall of the oil tank is connected to the inner wall of the aircraft.

[0016] In order to make the overall structure of the oil tank of the present invention more compact and light, the present invention sets the shape of the oil tank body according to the internal space of the aircraft under the premise of simplifying and strengthening the structure, and sets the oil tank body of the oil tank body as a ring body, and the inner ring of the entire oil tank is sleeved on the outer wall of the micro-turbojet engine inlet, and the outer ring is embedded in the inner wall of the aircraft. On the one hand, the structure of the oil tank body is more in line with the structure of the aircraft, so that the oil tank of the present invention can be more suitable for the volume and function requirements of the micro-turbojet engine and the aircraft, and the space occupancy rate of the oil system structure is reduced, and its overall structure is compact and simple; on the other hand, the connection stability between the oil tank body and the aircraft is enhanced.

[0017] Furthermore, two parallel wall panels are provided between the inner wall of the oil tank and the outer wall of the oil tank, and the inner wall of the oil tank, the outer wall of the oil tank and the two wall panels are enclosed to form the lubricating oil tank body;

[0018] There are a plurality of support columns, which are evenly distributed in the lubricating oil box body, and two ends of the support columns are respectively fixed on the two wall panels.

[0019] The inner wall of the oil tank, the outer wall of the oil tank and the two wall panels enclose a closed cavity for storing lubricating oil, preventing external gas, moisture, etc. from entering the interior of the box, thereby reducing box deformation caused by environmental changes.

[0020] When an aircraft takes off and lands, it will generate a large impact force, and the atmospheric pressure will also change accordingly. In addition, the flight process is accompanied by vibration. The oil tank must be able to withstand these external loads without deformation or damage, and at the same time be able to adapt to maneuvering flight or sudden airflow changes. The present invention sets a number of support columns in the oil tank, and uses the support columns to reinforce the oil tank, so that when the oil tank is subjected to internal and external loads, the support columns can withstand the force and disperse it, preventing the oil tank from being severely deformed or damaged due to excessive local pressure. Because the inner wall of the oil tank is connected to the engine, and the outer wall of the oil tank is connected to the inner wall of the aircraft, the two wall panels bear the main force. Fixing the two ends of the support column on the two wall panels can strengthen the rigidity and bearing capacity of the tank, limit the deformation degree of the oil tank, and enable the oil tank to adapt to various external loads during the aircraft test flight, and prevent the oil tank from being deformed or damaged by external forces, resulting in oil leakage, and then causing aircraft failure and test flight failure.

[0021] Specifically, the two wall panels are a front wall panel and a rear wall panel respectively, and the two wall panels have the same shape and are parallelly distributed longitudinally.

[0022] Furthermore, the heat exchange assembly includes two fuel joints, a plurality of heat dissipation pipes are arranged between the two fuel joints, one end of the fuel joint is provided with an opening, the opening can wrap the end of the heat dissipation pipe, and the other end of the fuel joint passes through the wall plate and is fixedly connected to the wall plate;

[0023] The end of the fuel connector located outside the wall panel is a fuel end cover, one of the fuel end covers of the heat exchange assembly is provided with a fuel inlet pipe, and the other fuel end cover of the heat exchange assembly is provided with a fuel outlet.

[0024] The two ends of the heat exchange assembly are fixedly connected to the two wall plates of the lubricating oil tank body by argon arc welding, and the two groups of the heat exchange assembly are connected by a fuel connecting pipe. One end of the heat exchange assembly is welded to the fuel inlet pipe, and the other end of the fuel inlet pipe is connected to the fuel tank. The other end of the heat exchange assembly is welded to the fuel outlet pipe, and the fuel outlet pipe is connected to the engine fuel supply mechanism.

[0025] Fuel is introduced into the heat dissipation pipe as a cooling medium, and the heat dissipation pipe is immersed in lubricating oil as a whole. When the engine is working, the high-temperature lubricating oil at about 180° discharged from the bearing cavity flows through the heat dissipation pipe, and the high-temperature lubricating oil and the cold flow fuel in the heat dissipation pipe undergo heat exchange, thereby cooling the high-temperature lubricating oil. The temperature difference of the lubricating oil heat dissipation reaches between 100° and 120°. At the same time, the fuel flowing in the heat dissipation pipe is heated, thereby improving the combustion efficiency of the fuel.

[0026] When the above scheme is implemented, the fuel inlet pipe and the fuel outlet can be connected to the two ends of each heat exchange component respectively, so that each heat exchange component forms an independent circulation loop; it is also possible to connect several heat exchange components into an integral heat exchange circulation loop through a fuel connecting pipe, and then connect the fuel inlet pipe to one end of one of the heat exchange components and connect the fuel outlet to one end of another heat exchange component.

[0027] Furthermore, a plurality of the heat dissipation pipes are arranged in parallel, and an extension direction of the heat dissipation pipes is perpendicular to a flow direction of the lubricating oil in the lubricating oil box.

[0028] This flow mode can make all the lubricating oil contact with the heat dissipation pipe, which can evenly dissipate the heat of the lubricating oil. At the same time, the heat in the lubricating oil can be transferred to the heat dissipation pipe more effectively.

[0029] Furthermore, the plurality of heat dissipation tubes are evenly spaced apart to form a plurality of heat dissipation surfaces parallel to each other, and the plurality of heat dissipation tubes in one heat dissipation surface are evenly spaced apart.

[0030] In order to increase the contact area with the lubricating oil, a number of heat dissipation tubes are evenly distributed to form a number of heat dissipation surfaces, so that the lubricating oil can be cooled quickly and evenly after passing through the heat dissipation tubes.

[0031] Furthermore, it also includes an oil-gas separation component and an oil inlet, wherein the oil-gas separation component is fixed inside the lubricating oil box, and the oil inlet is communicated with the oil-gas separation component;

[0032] A ventilation component is provided near the top of the lubricating oil box.

[0033] An oil-gas separation component is arranged near the oil inlet in the lubricating oil tank to separate the oil and gas mixture discharged from the engine bearing cavity into the lubricating oil tank. The separated gas is discharged into the atmosphere through the ventilation component on the lubricating oil tank, and the separated lubricating oil flows to the oil storage area of ​​the lubricating oil tank through the waist-shaped holes on the bottom plate of the oil-gas separation cylinder under the action of its own weight. The gas content in the lubricating oil is reduced by oil-gas separation, which ensures the continuity of the lubricating oil flow, and ensures the purity and stability of the lubricating oil, thereby maintaining the normal operation of the engine.

[0034] The oil-gas separation component is set in the lubricating oil box. Because the temperature of the lubricating oil after use is high, the temperature of the gas after separation is high, and the thermal expansion and contraction of the gas may increase the internal pressure of the lubricating oil box, and there is a risk of explosion and damage of the box. A ventilation component is set on the lubricating oil box to allow the separated gas to be discharged smoothly.

[0035] The breather assembly is arranged near the top of the lubricating oil box so that the separated gas can be automatically discharged from the top.

[0036] Furthermore, the lubricating oil box body is provided with an oil outlet near the bottom;

[0037] The oil-gas separation component, the heat exchange component and the filter component are arranged on both sides of the longitudinal axis of the lubricating oil box;

[0038] The oil-gas separation component, the heat exchange component and the filter component are sequentially distributed from top to bottom between the oil inlet and the oil outlet;

[0039] The oil outlet is located between two adjacent groups of the filter components on both sides of the longitudinal axis of the lubricating oil box, and the ventilation component is located between two adjacent groups of the oil-gas separation components on both sides of the longitudinal axis of the lubricating oil box.

[0040] The heat exchange component is located below the oil-gas separation component and the filter component is located below the heat exchange component. The used high-temperature lubricating oil enters the oil-gas separation component through the oil inlet for oil-gas separation. The separated gas fills upward and is discharged from the ventilation component above the lubricating oil box. The separated lubricating oil naturally flows downward to the heat exchange component for cooling. After that, the cooled lubricating oil flows to the filter component, which filters impurities and eliminates bubbles. Finally, it naturally flows to the oil outlet and is pumped out for recycling. The lubricating oil is allowed to flow and circulate naturally in the lubricating oil box. The lubricating oil flows from high to low, which reduces the retention time of the lubricating oil in the lubricating oil box and reduces the risk of lubricating oil deterioration.

[0041] When the oil-gas separation component, heat exchange component and filter component are only set on one side, if the lubricating oil flowing into the oil inlet can only flow from one side of the lubricating oil box to the bottom, the effective utilization space in the lubricating oil box is small, and the structure cannot be simplified and the volume cannot be reduced to meet the requirements of various micro-aircraft for the volume of the lubricating oil box; if the lubricating oil flowing into the oil inlet can flow from both sides of the lubricating oil box to the bottom, the side without the separation component, heat exchange component and filter component cannot thoroughly process the lubricating oil, and the recycled lubricating oil may interfere with the normal use of the engine. The oil-gas separation component, heat exchange component and filter component are set on both opposite sides of the lubricating oil box, which can improve the efficiency and quality of lubricating oil treatment and ensure the stable circulation and good performance of the lubricating oil during use.

[0042] The entire oil tank is divided into several compartments through the filtering system. When the aircraft has large-angle pitch and other flight attitude changes, the defoaming plate can slow down the oil shaking, maintain the stability of the oil flow in the oil suction area, ensure that the oil pump fully absorbs oil, and ensure that the oil tank works stably and reliably.

[0043] The oil outlet is located between two groups of filter components, ensuring that the lubricating oil flowing to the oil outlet meets the requirements for secondary use and can be discharged directly, thereby improving the purity of the oil and the operating reliability of the equipment.

[0044] Furthermore, the filter assembly is provided with a defoaming plate, and the defoaming plate can completely cover the cross section of the lubricating oil box body, and the defoaming plate is provided with a plurality of perforations.

[0045] The defoaming plate is used to eliminate bubbles caused by changes in the flow state of the oil due to external factors such as changes in flight attitude, acceleration and deceleration, etc. It is used to filter out solid particles flowing through small holes, to slow down the sway of the lubricating oil, to maintain the stability of the lubricating oil flow in the lubricating oil suction pipe area, and to ensure that the lubricating oil pump fully absorbs oil.

[0046] The defoaming plate has a number of small holes, which can filter out solid particles flowing through the small holes, prevent solid particles from entering the oil suction area, and prevent important accessories such as the lubricating oil pump from being stuck; at the same time, it can be used to eliminate bubbles caused by changes in the flow state of the oil due to external factors such as changes in flight attitude, acceleration and deceleration, and reduce the gas content in the oil.

[0047] The defoaming plate can completely cover the cross-section of the lubricating oil tank body, so an independent oil storage area can be formed between the two defoaming plates. When the flight attitude changes, the defoaming plate can slow down the shaking of the lubricating oil, maintain the stability of the lubricating oil flow state in the oil suction port area, and ensure that the lubricating oil pump fully absorbs the oil.

[0048] In summary, the present invention has the following beneficial effects compared with the prior art:

[0049] 1. The lubricating oil box body is provided with a support column and stores lubricating oil and various functional components inside, so the entire lubricating oil system pipeline is short, so that the lubricating oil box of the present invention is highly integrated, simplified in structure, and strengthened in rigidity, so that it is suitable for both ground test and flight test of the engine;

[0050] 2. The present invention sets the shape of the oil tank body according to the internal space of the aircraft on the premise of simplifying and strengthening the structure. The inner ring of the entire oil tank is sleeved on the outer wall of the air inlet of the micro turbojet engine, and the outer ring is embedded in the inner wall of the aircraft. This design reduces the space occupation rate of the oil system structure, and its overall structure is compact and simple;

[0051] 3. An air outlet, an oil inlet and an oil outlet are arranged on the lubricating oil box from top to bottom, and an oil-gas separation component, a heat exchange component and a filter component are symmetrically arranged between the oil inlet and the oil outlet from top to bottom, so as to make full use of the internal space of the lubricating oil box and improve the efficiency of lubricating oil treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0053] Figure 1 This is a schematic diagram of the overall structure of this application;

[0054] Figure 2 for Figure 1 Rear view of

[0055] Figure 3 A schematic diagram of the structure with the front wall of the fuel tank removed for this application;

[0056] Figure 4 For this application Figure 1 Left view with the outer wall of the fuel tank removed;

[0057] Figure 5 A schematic diagram of the structure of the lubricating oil tank body of this application without the inner wall and outer wall of the oil tank;

[0058] Figure 6 A schematic structural diagram of an implementation scheme of a heat exchange component of the present application;

[0059] The names corresponding to the reference numerals are: 1. lubricating oil box; 2. oil-gas separation assembly; 3. ventilation assembly; 4. heat exchange assembly; 5. filter assembly; 6. lubricating oil suction assembly; 7. front mounting block; 8. front wall plate of the fuel tank; 9. rear wall plate of the fuel tank; 10. mounting base plate; 11. cross beam; 12. rectangular square beam; 13. inner wall of the fuel tank; 14. outer wall of the fuel tank; 15. oil return duct; 16. duct joint; 17. oil-gas separation cylinder; 18. ventilation elbow; 19. elbow joint; 20. fuel inlet pipe; 21. left heat exchange assembly; 22. right heat exchange assembly; 23. fuel connecting pipe; 24. heat dissipation pipe; 25. fuel joint; 26. fuel end cover; 27. lubricating oil suction pipe; 28. suction pipe joint. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0061] Example:

[0062] like Figure 1-Figure 6 As shown, a novel multifunctional integrated oil tank for a micro turbojet engine comprises an oil tank body 1, a heat exchange component 4 and a filter component 5. The oil tank body 1 is used to store oil, and the heat exchange component 4 and the filter component 5 are both arranged in the oil tank body 1 and fixedly connected;

[0063] The lubricating oil box 1 is provided with a support column inside, and the support column is used to support the inner wall of the lubricating oil box 1.

[0064] In the prior art, each functional component of the oil tank 1 is arranged outside the oil tank 1, and the connecting pipes are numerous and long, which makes the oil tank 1 complex in structure and heavy in weight. In the engine flight test, it may reduce power output or increase fuel consumption, and increase the risk of failure. At the same time, due to the poor overall rigidity of the oil tank 1, the oil tank 1 may be deformed, broken or leaked, which may lead to safety risks and is difficult to meet the performance requirements of the engine flight test for the oil tank.

[0065] Specifically, a cavity for containing lubricating oil is provided inside the lubricating oil box 1, and the box body of the lubricating oil box 1 is the outer shell of the lubricating oil cavity. The present application integrates a number of functional components inside the lubricating oil box 1 for storing lubricating oil and sets a support column inside the lubricating oil box 1, thereby reducing the setting of connecting parts such as connecting pipes and strengthening the structural strength of the lubricating oil box 1, thereby improving the volume, weight, rigidity and function of the lubricating oil box described in the present application, so as to be suitable for both ground test and flight test of the engine.

[0066] It includes a lubricating oil box 1, a heat exchange component 4 and a filter component 5. The heat exchange component 4 is used to cool the lubricating oil, and the filter component 5 is used to filter the lubricating oil. Finally, the treated lubricating oil is pumped out to the engine again for reuse.

[0067] Compared with the prior art, the complex structure of several connecting pipelines and boxes not only increases the difficulty of installation and maintenance, but also may lead to increased fluid resistance, affect the efficiency of the lubricating oil system, and increase the slippage of the connection points and the failure rate in the lubricating oil system circuit. The interior of the lubricating oil box 1 of the present invention not only stores lubricating oil, but also accommodates several functional components, which can effectively reduce the length and / or number of connecting pipes. As a result, the space in the lubricating oil box 1 is effectively utilized, reducing the overall volume and weight to meet the requirements of micro-turbojet engines and micro-aircraft for the mass and volume of lubricating oil boxes. At the same time, due to the simple overall structure, the number of system failure points is reduced and it is convenient for later maintenance.

[0068] Support columns are provided inside the oil box 1, which can, on the one hand, reinforce the oil box 1 and improve the overall stiffness, load-bearing capacity and deformation resistance of the oil box 1. The inner wall of the oil box 1 is supported to constrain and support the oil box. When the oil box 1 is affected by air pressure, external loads, etc. inside and outside, the support columns can effectively disperse the external loads to the entire box structure. This reduces the concentration of local stress and reduces deformation or damage caused by excessive stress. The support columns can be reasonably arranged and connected so that each support column can bear a certain load, thereby avoiding deformation of the box caused by excessive force at a single point. On the other hand, when the vibration of the engine is transmitted to the oil box 1, the vibration may cause the connection between the oil box 1 and the internal functional components or the connection points itself to loosen, thereby causing problems such as oil leakage. After each functional component is arranged inside the oil tank 1, the support column provides support and installation points for the functional components inside the oil tank 1. Compared with the prior art that uses pipelines to connect various functional components, this solution can directly fix the functional components on the inner wall of the oil tank 1, and strengthen the connection strength and / or fixing points, thereby improving the stability of the connection points, preventing the connection failure of the oil tank 1 and the functional components inside due to aircraft vibration, and allowing the overall structure of the oil tank 1 to better adapt to the shaking and take-off and landing of the aircraft during test flight.

[0069] As an implementable embodiment of the above scheme, the volume of the oil tank 1 is determined according to the internal structural space of the overall aircraft, so that the volume of the oil tank 1 is larger than the flight envelope of the aircraft and the oil consumption of the micro turbojet engine, ensuring that after various functional components are set in the oil tank 1, the storage capacity of the oil can still store the oil required for the operation of the engine.

[0070] As a feasible implementation of the above scheme, the heat exchange component 4 and the filter component 5 are both detachably connected to the inner wall of the lubricating oil box body 1, which is convenient for disassembly and assembly and subsequent maintenance and repair.

[0071] As a preferred solution of the above scheme, a lubricating oil suction assembly 6 is provided at the oil outlet, including a lubricating oil suction pipe 27 and a suction pipe joint 28. The lubricating oil suction pipe 27 passes through the oil inlet, one end of the suction pipe is designed as a groove and is immersed in the lubricating oil in the lubricating oil box 1, and the other end is welded to the suction pipe joint 28, and the suction pipe joint 28 is connected to the engine lubricating oil pump to realize the supply of lubricating oil.

[0072] Preferably, the lubricating oil suction pipe 27 horizontally penetrates into the lubricating oil tank body 1 and extends into the middle of the lubricating oil tank body 1. The center of the lubricating oil suction pipe 27 is close to the upper surface of the mounting base plate 10, ensuring that the oil tank can stably supply oil to the engine under various flight attitudes.

[0073] Furthermore, the oil tank body 1 is a ring body, the inner side of the ring body is the oil tank inner wall 13, the outer side of the ring body is the oil tank outer wall 14, the oil tank inner wall 13 is connected to the engine, and the oil tank outer wall 14 is connected to the inner wall of the aircraft.

[0074] In order to make the overall structure of the oil tank of the present invention more compact and light, the present invention sets the shape of the oil tank body 1 according to the internal space of the aircraft under the premise of simplifying and strengthening the structure, and sets the oil tank body 1 of the oil tank body 1 as a ring body, and the inner ring of the entire oil tank is sleeved on the outer wall of the micro-turbojet engine inlet, and the outer ring is embedded in the inner wall of the aircraft. On the one hand, the structure of the oil tank body 1 is more in line with the structure of the aircraft, so that the oil tank of the present invention can be more suitable for the volume and function requirements of the micro-turbojet engine and the aircraft, and the space occupancy rate of the oil system structure is reduced, and its overall structure is compact and simple; on the other hand, the connection stability of the oil tank body 1 and the aircraft is enhanced.

[0075] As an implementable embodiment of the above scheme, the lubricating oil tank body 1 is formed by sheet metal, including an inner wall 13 and an outer wall 14. The inner wall 13 of the oil tank is designed according to the shape of the air inlet of the micro turbojet engine, so that the inner wall 13 of the oil tank is sleeved on the outside of the engine air inlet, and the outer wall 14 of the oil tank is designed according to the internal structural space of the aircraft, so that the outer wall 14 of the oil tank is embedded in the aircraft.

[0076] As a feasible implementation scheme of the above scheme, between the inner wall 13 of the oil tank and the outer wall 14 of the oil tank are the front wall plate 8 and the rear wall plate 9 of the oil tank. The inner wall 13 of the oil tank and the inner circle of the front wall plate 8 and the inner circle of the rear wall plate 9 of the oil tank are welded as a whole. The outer wall 14 of the oil tank and the outer circle of the front wall plate 8 and the outer circle of the rear wall plate 9 of the oil tank are welded as a whole.

[0077] As an implementable embodiment of the above scheme, the front wall plate 8 and the rear wall plate 9 of the fuel tank are used as supporting structures, and the thickness of the front wall plate 8 and the rear wall plate 9 of the fuel tank is 10 mm.

[0078] As an implementable embodiment of the above scheme, the bottom of the oil tank 1 is a horizontally arranged mounting base plate 10, which is the main load-bearing part and has a thickness of 10 mm. The upper plane of the mounting base plate 10 is welded to the bottom surface of the oil tank front wall plate 8 and the bottom surface of the oil tank rear wall plate 9. Six bosses are arranged on the bottom surface of the mounting base plate 10, and the bosses are provided with threads. The oil tank 1 is fixed to the aircraft through the bosses on the oil tank 1. The connection stability of the oil tank 1 is further enhanced to prevent the oil tank 1 from moving along the axis direction of the engine air intake.

[0079] Furthermore, two parallel wall panels are provided between the oil tank inner wall 13 and the oil tank outer wall 14, and the oil tank inner wall 13, the oil tank outer wall 14 and the two wall panels are enclosed to form the lubricating oil tank body 1;

[0080] There are a plurality of support columns, which are evenly distributed in the lubricating oil box 1, and both ends of the support columns are respectively fixed on the two wall panels.

[0081] The oil tank inner wall 13, the oil tank outer wall 14 and the two wall panels enclose a closed cavity for storing lubricating oil, preventing external gas, moisture, etc. from entering the interior of the tank, thereby reducing deformation of the tank caused by environmental changes.

[0082] When the aircraft takes off and lands, a large impact force will be generated, and the atmospheric pressure will also change accordingly. In addition, the flight process is accompanied by vibration. The oil tank 1 must be able to withstand these external loads without deformation or damage, and at the same time be able to adapt to maneuvering flight or sudden airflow changes. The present invention sets a number of support columns in the oil tank 1, and uses the support columns to reinforce the oil tank 1, so that when the oil tank 1 is subjected to internal and external loads, the support columns can withstand the force and disperse it, preventing the oil tank 1 from being seriously deformed or damaged due to excessive local pressure. Because the inner wall 13 of the oil tank is connected to the engine, and the outer wall 14 of the oil tank is connected to the inner wall of the aircraft, the two wall panels bear the main force. Fixing the two ends of the support column on the two wall panels can strengthen the rigidity and bearing capacity of the box, limit the deformation degree of the oil tank 1, and enable the oil tank to adapt to various external loads during the aircraft test flight, and prevent the oil tank 1 from being deformed or damaged by external forces, resulting in oil leakage, and then causing aircraft failure and test flight failure.

[0083] Specifically, the two wall panels are respectively a front wall panel 8 of the fuel tank and a rear wall panel 9 of the fuel tank. The two wall panels have the same shape and are parallel and longitudinally distributed.

[0084] As a feasible implementation scheme of the above-mentioned support column scheme, in order to improve the rigidity of the lubricating oil tank body 1 under a vibration environment, four φ8×1 cross beams 11 are added between the front wall plate 8 and the rear wall plate 9 of the oil tank, and four circular grooves are designed on the upper and lower left and right parts of the front wall plate 8 and the rear wall plate 9 of the oil tank, respectively. The four cross beams 11 are placed in the grooves and welded to the front wall plate 8 and the rear wall plate 9 of the oil tank as a whole.

[0085] As an implementable embodiment of the above scheme, in order to improve the overall stiffness of the oil-gas separation assembly 22 under a vibration environment, two 7×5mm rectangular square beams 12 are added between the front wall plate 8 and the rear wall plate 9 of the fuel tank, and two circular grooves are designed on the left and right sides of the middle of the front wall plate 8 and the rear wall plate 9 of the fuel tank, respectively. The two rectangular square beams 12 are placed in the grooves and welded to the front wall plate 8 and the rear wall plate 9 of the fuel tank as a whole.

[0086] Furthermore, the heat exchange assembly 4 includes two fuel connectors 25, a plurality of heat dissipation pipes 24 are arranged between the two fuel connectors 25, one end of the fuel connector 25 is provided with an opening, the opening can wrap the end of the heat dissipation pipe 24, and the other end of the fuel connector 25 passes through the wall plate and is fixedly connected to the wall plate;

[0087] The end of the fuel connector 25 located outside the wall panel is a fuel end cover 26. One of the fuel end covers 26 of the heat exchange assembly 4 is provided with a fuel inlet pipe 20, and the other fuel end cover 26 of the heat exchange assembly 4 is provided with a fuel outlet.

[0088] The two ends of the heat exchange assembly 4 are fixedly connected to the two wall panels of the lubricating oil tank body 1 by argon arc welding, and the two groups of the heat exchange assembly 4 are connected by a fuel connecting pipe 23. The free end of one of the heat exchange assembly 4 is welded to the fuel inlet pipe 20, and the other end of the fuel inlet pipe 20 is connected to the fuel tank. The free end of the other heat exchange assembly 4 is welded to the fuel outlet pipe, and the fuel outlet pipe is connected to the engine fuel supply mechanism.

[0089] Fuel is introduced into the heat dissipation pipe 24 as a cooling medium, and the heat dissipation pipe 24 is immersed in lubricating oil as a whole. When the engine is working, the high-temperature lubricating oil at an angle of about 180° discharged from the bearing cavity flows through the heat dissipation pipe 24, and the high-temperature lubricating oil and the cold flow fuel in the heat dissipation pipe 24 undergo heat exchange, thereby cooling the high-temperature lubricating oil. The temperature difference of the lubricating oil heat dissipation reaches between 100° and 120°. At the same time, the fuel flowing in the heat dissipation pipe 24 is heated, thereby improving the combustion efficiency of the fuel.

[0090] When the above scheme is implemented, the fuel inlet pipe 20 and the fuel outlet can be connected to the two ends of each heat exchange component 4 respectively, so that each heat exchange component 4 forms an independent circulation loop; it is also possible to connect several heat exchange components 4 into an integral heat exchange circulation loop through the fuel connecting pipe 23, and then connect the fuel inlet pipe 20 to one end of one of the heat exchange components 4, and connect the fuel outlet to one end of another heat exchange component 4.

[0091] As an implementable embodiment of the above scheme, the wall panel of the oil tank body 1 away from the aircraft side is the oil tank front wall panel 8, and the wall panel of the oil tank body 1 close to the aircraft side is the oil tank rear wall panel 9, the fuel inlet pipe 20 and the fuel outlet pipe are located on the side of the oil tank front wall panel 8, and the fuel connecting pipe 23 is located on the side of the oil tank front wall panel 8.

[0092] Furthermore, a plurality of the heat dissipation pipes 24 are arranged in parallel, and the extending direction of the heat dissipation pipes 24 is perpendicular to the flow direction of the lubricating oil in the lubricating oil box 1 .

[0093] This flow mode enables all the lubricating oil to contact the radiating pipe 24, and can evenly dissipate the heat of the lubricating oil. At the same time, the heat in the lubricating oil is more effectively transferred to the radiating pipe 24.

[0094] Furthermore, the plurality of heat dissipation tubes 24 are evenly spaced apart to form a plurality of heat dissipation surfaces parallel to each other, and the plurality of heat dissipation tubes 24 in one heat dissipation surface are evenly spaced apart.

[0095] In order to increase the contact area with the lubricating oil, a plurality of heat dissipation tubes 24 are evenly distributed to form a plurality of heat dissipation surfaces, so that the lubricating oil can be cooled quickly and evenly after passing through the heat dissipation tubes 24 .

[0096] As an implementable embodiment of the above scheme, some of the heat dissipation tubes 24 are distributed in the same plane to form a heat dissipation surface, and some of the heat dissipation tubes 24 form several heat dissipation surfaces parallel to each other; some of the heat dissipation tubes 24 in one heat dissipation surface are evenly spaced and some of the heat dissipation surfaces are evenly spaced.

[0097] As an implementable embodiment of the above scheme, the heat dissipation pipe 24 is composed of 42 round tubes in 6 rows and 7 columns, the heat dissipation area of ​​the heat dissipation pipe 24 is 113 square millimeters, the heat dissipation power reaches 4000KW, the heat dissipation pipe 24 and the heat dissipation pipe 24 bracket are welded by argon arc welding, and the heat dissipation pipe 24 bracket and the fuel joint 25 are welded by argon arc welding.

[0098] Furthermore, it also includes an oil-gas separation component 2 and an oil inlet, wherein the oil-gas separation component 2 is fixed inside the lubricating oil box 1, and the oil inlet is communicated with the oil-gas separation component 2;

[0099] A ventilation assembly 3 is provided near the top of the lubricating oil box 1 .

[0100] An oil-gas separation component 2 is arranged near the oil inlet in the lubricating oil tank for separating the oil-gas mixture discharged from the engine bearing cavity into the lubricating oil tank body 1. The separated air is discharged into the atmosphere through the ventilation component 3 on the lubricating oil tank, and the separated lubricating oil flows to the oil storage area of ​​the lubricating oil tank through the waist-shaped holes on the bottom plate of the oil-gas separation cylinder 17 under the action of its own weight. The gas content in the lubricating oil is reduced by oil-gas separation, which ensures the continuity of the lubricating oil flow, and ensures the purity and stability of the lubricating oil, thereby maintaining the normal operation of the engine.

[0101] The oil-gas separation component 2 is arranged in the lubricating oil tank 1. Since the temperature of the lubricating oil after use is relatively high, the temperature of the gas after separation is also high. The thermal expansion and contraction of the gas may increase the internal pressure of the lubricating oil tank 1, and there is a risk of explosion and damage of the tank. A ventilation component 3 is arranged on the lubricating oil tank 1 to allow the separated gas to be discharged smoothly.

[0102] The breather assembly 3 is arranged near the top of the lubricating oil box 1 so that the separated gas can be automatically discharged from the top.

[0103] As an implementable embodiment of the above scheme, the oil-gas separation component 2 is arranged on the top of the inner wall of the lubricating oil box body 1. The oil-gas separation component 2 includes an oil return conduit 15, a conduit joint 16M14×1 and an oil-gas separation cylinder 17. One end of the oil return conduit 15 is welded to the oil-gas separation cylinder 17, and the other end passes through the reserved hole of the front wall plate 8 of the oil tank and is welded to the conduit joint 16M14×1. The conduit joint 16M14×1 is connected to the lubricating oil return pipe of the engine. A vent hole with a radius of 3 mm is provided on the top of the oil-gas separation cylinder 17, and 4 waist-shaped holes are provided on the bottom plate to achieve oil and gas discharge.

[0104] As a preferred solution of the above-mentioned feasible implementation plan, in order to improve the overall rigidity of the oil-gas separation component 2, the length of the cantilever of the oil return conduit 15 is designed to be 70mm, the distance between the welding point of the oil return conduit 15 and the oil-gas separation cylinder 17 and the welding point of the reserved hole of the front wall plate 8 of the fuel tank is 48mm, and the oil-gas separation component 2 is vertically welded to the rectangular square beam 12 to increase the fixed constraint. The integration height of the oil-gas separation component 2 is designed according to the flight attitude of the aircraft such as large-angle pitch and the amount of lubricating oil used in the engine. The distance between the bottom plate of the oil-gas separation cylinder 17 and the upper surface of the mounting bottom plate 10 is 102mm, ensuring that the oil-gas separation cylinder 17 in various flight attitudes will not be submerged in lubricating oil, while improving the oil-gas separation efficiency of the oil-gas separation cylinder 17.

[0105] As a preferred embodiment of the above-mentioned feasible implementation scheme, the ventilation assembly 3 includes a ventilation elbow 18 and an elbow joint 19M18×1.5. One end of the ventilation elbow 18 is welded to the elbow joint 19M18×1.5, and the other end is welded to the exhaust port at the top of the fuel tank outer wall 14. The opening direction of the conduit joint elbow joint 19M18×1.5 faces the fuel tank front wall plate 8 and is connected to the magazine exhaust pipe to discharge the air separated by the oil and gas separation assembly 2 into the atmosphere.

[0106] Furthermore, the lubricating oil tank body 1 is provided with an oil outlet near the bottom;

[0107] The oil-gas separation component 2, the heat exchange component 4 and the filter component 5 are arranged on both sides of the longitudinal axis of the lubricating oil box 1;

[0108] The oil-gas separation component 2, the heat exchange component 4 and the filter component 5 are sequentially distributed from top to bottom between the oil inlet and the oil outlet;

[0109] The oil outlet is located between two adjacent groups of the filter components 5 on both sides of the longitudinal axis of the oil tank body 1 , and the ventilation component 3 is located between two adjacent groups of the oil-gas separation components 2 on both sides of the longitudinal axis of the oil tank body 1 .

[0110] The heat exchange component 4 is located below the oil-gas separation component 2, and the filter component 5 is located below the heat exchange component 4, so that the used high-temperature lubricating oil enters the oil-gas separation component 2 through the oil inlet for oil-gas separation, and the separated gas is filled upward and discharged from the ventilation component 3 above the lubricating oil box 1. The separated lubricating oil naturally flows downward to the heat exchange component 4 for cooling, and then the cooled lubricating oil flows to the filter component 5, so that the filter component 5 filters impurities and eliminates bubbles, and finally naturally flows to the oil outlet and is extracted for recycling. The lubricating oil is naturally circulated in the lubricating oil box 1, and the lubricating oil flows from high to low, which reduces the retention time of the lubricating oil in the lubricating oil box 1 and reduces the risk of lubricating oil deterioration.

[0111] When the oil-gas separation component 2, the heat exchange component 4 and the filter component 5 are only arranged on one side, if the lubricating oil flowing into the oil inlet can only flow from one side of the lubricating oil tank 1 to the bottom, the effective utilization space in the lubricating oil tank 1 is small, and the structure cannot be simplified and the volume cannot be reduced to meet the volume requirements of various micro-aircraft for the lubricating oil tank 1; if the lubricating oil flowing into the oil inlet can flow from both sides of the lubricating oil tank 1 to the bottom, the side without the separation component, the heat exchange component 4 and the filter component 5 cannot thoroughly process the lubricating oil, and the recycled lubricating oil may interfere with the normal use of the engine. The oil-gas separation component 2, the heat exchange component 4 and the filter component 5 are arranged on both opposite sides of the lubricating oil tank 1, which can improve the efficiency and quality of lubricating oil processing and ensure the stable circulation and good performance of the lubricating oil during use.

[0112] The entire oil tank is divided into several compartments through the filtering system. When the aircraft has large-angle pitch and other flight attitude changes, the defoaming plate can slow down the oil shaking, maintain the stability of the oil flow in the oil suction area, ensure that the oil pump fully absorbs oil, and ensure that the oil tank works stably and reliably.

[0113] The oil outlet is located between the two groups of filter components 5, ensuring that the lubricating oil flowing to the oil outlet meets the requirements for secondary use and can be discharged directly, thereby improving the purity of the oil and the operating reliability of the equipment.

[0114] Furthermore, the filter assembly 5 is provided with a defoaming plate, and the defoaming plate can completely cover the cross section of the lubricating oil box body 1, and the defoaming plate is provided with a plurality of perforations.

[0115] The defoaming plate is used to eliminate bubbles caused by changes in the flow state of the oil due to external factors such as changes in flight attitude, acceleration and deceleration, etc., to filter out solid particles flowing through the small holes, to slow down the shaking of the lubricating oil, to maintain the stability of the lubricating oil flow state in the area of ​​the lubricating oil suction pipe 27, and to ensure that the lubricating oil pump fully absorbs oil.

[0116] The defoaming plate has a number of small holes, which can filter out solid particles flowing through the small holes, prevent solid particles from entering the oil suction area, and prevent important accessories such as the lubricating oil pump from being stuck; at the same time, it can be used to eliminate bubbles caused by changes in the flow state of the oil due to external factors such as changes in flight attitude, acceleration and deceleration, and reduce the gas content in the oil.

[0117] The defoaming plate can completely cover the cross section of the lubricating oil tank 1, so an independent oil storage area can be formed between the two defoaming plates. When the flight attitude changes, the defoaming plate can slow down the shaking of the lubricating oil, maintain the stability of the lubricating oil flow state in the oil suction port area, and ensure that the lubricating oil pump fully absorbs the oil.

[0118] As an implementable embodiment of the above scheme, two defoaming plates are respectively welded vertically and symmetrically to the inner side of the outer wall of the box body.

[0119] The above solution is installed in detail:

[0120] Put the inner wall 13 of the oil tank on the engine air intake duct so that the exhaust direction of the ventilation assembly 3 is consistent with the engine jet direction, the front mounting block 7 is fixedly connected to the side wall of the magazine by bolts, the mounting base plate 10 is fixedly connected to the bottom of the magazine by bolts, the oil tank fuel inlet pipe 20 is connected to the fuel tank piping system on the missile, the left heat exchange assembly 21 and the front wall plate 8 end of the oil tank are connected to the engine fuel supply mechanism piping system, the oil tank oil-gas separation assembly 2 is connected to the oil return piping system on the engine, the oil suction assembly 6 is connected to the oil pump piping system, and all the piping systems are neatly arranged on the engine; the oil tank ventilation assembly 3 is connected to the external oil filling piping system, and 4 to 4.2L of oil is added to the oil tank, the external oil filling piping system is removed, and the ventilation assembly 3 is connected to the ventilation piping system.

[0121] When the above scheme is used:

[0122] Under the suction action of the lubricating oil pump, the lubricating oil in the lubricating oil tank enters the lubricating oil pump through the lubricating oil suction assembly 6, and is transported to the lubricating nozzle inside the engine through the pipeline after being pressurized by the lubricating oil pump, and is sprayed to lubricate and cool the internal bearings of the engine. After lubrication and cooling, the high-temperature lubricating oil flows back to the oil-gas separation assembly 2 through the lubricating oil return pipe system, and the air and lubricating oil are separated by the oil-gas separation assembly 2. The air is discharged into the atmosphere through the ventilation assembly 3, and the lubricating oil drips into the oil storage area in the oil tank under the action of its own weight. The oil storage area in the oil tank is provided with a heat exchange assembly 4, and the cooling medium fuel oil flows inside the heat exchange assembly 4. The heat exchange assembly 4 is immersed in the lubricating oil as a whole. When the high-temperature lubricating oil passes through the heat exchange assembly 4, the high-temperature lubricating oil and the fuel in the heat exchange assembly 4 pipe are fully heat-exchanged, realizing the cooling of the high-temperature lubricating oil. At the same time, the fuel flowing in the pipe is heated, which improves the combustion efficiency of the fuel.

[0123] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A novel multifunctional integrated oil tank for a micro turbojet engine, comprising an oil tank body (1), a heat exchange component (4) and a filter component (5), characterized in that: The lubricating oil box (1) is used to store lubricating oil, and the heat exchange component (4) and the filter component (5) are both arranged in the lubricating oil box (1) and fixedly connected; A support column is provided inside the lubricating oil box (1), and the support column is used to support the inner wall of the lubricating oil box (1).

2. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 1, characterized in that: The lubricating oil tank body (1) is a ring body, the inner side of the ring body is the inner wall (13) of the oil tank, the outer side of the ring body is the outer wall (14) of the oil tank, the inner wall (13) of the oil tank is connected to the engine, and the outer wall (14) of the oil tank is connected to the inner wall of the aircraft.

3. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 2, characterized in that: Two parallel wall panels are provided between the oil tank inner wall (13) and the oil tank outer wall (14); the oil tank inner wall (13), the oil tank outer wall (14) and the two wall panels are combined to form the lubricating oil tank body (1); There are a plurality of support columns, which are evenly distributed in the lubricating oil box (1), and the two ends of the support columns are respectively fixed on the two wall panels.

4. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 3, characterized in that: The heat exchange assembly (4) comprises two fuel connectors (25), a plurality of heat dissipation pipes (24) are arranged between the two fuel connectors (25), one end of the fuel connector (25) is provided with an opening, the opening can wrap around the end of the heat dissipation pipe (24), and the other end of the fuel connector (25) passes through the wall plate and is fixedly connected to the wall plate; The end of the fuel connector (25) located outside the wall panel is a fuel end cover (26), one of the fuel end covers (26) of the heat exchange assembly (4) is provided with a fuel inlet pipe (20), and the other fuel end cover (26) of the heat exchange assembly (4) is provided with a fuel outlet.

5. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 4, characterized in that: A plurality of the heat dissipation pipes (24) are arranged in parallel, and the extension direction of the heat dissipation pipes (24) is perpendicular to the flow direction of the lubricating oil in the lubricating oil box (1).

6. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 5, characterized in that: The plurality of heat dissipation tubes (24) are evenly spaced to form a plurality of heat dissipation surfaces that are parallel to each other, and the plurality of heat dissipation tubes (24) in one heat dissipation surface are evenly spaced.

7. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 1, characterized in that: It also includes an oil-gas separation component (2) and an oil inlet, wherein the oil-gas separation component (2) is fixed inside the lubricating oil box (1), and the oil inlet is in communication with the oil-gas separation component (2); A ventilation assembly (3) is provided near the top of the lubricating oil box (1).

8. A novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 7, characterized in that: The lubricating oil box (1) is provided with an oil outlet near the bottom; The oil-gas separation component (2), the heat exchange component (4) and the filter component (5) are arranged on both sides of the longitudinal axis of the lubricating oil box (1); The oil-gas separation component (2), the heat exchange component (4) and the filter component (5) are sequentially distributed from top to bottom between the oil inlet and the oil outlet; The oil outlet is located between two adjacent groups of filter components (5) on both sides of the longitudinal axis of the lubricating oil box (1), and the ventilation component (3) is located between two adjacent groups of oil-gas separation components (2) on both sides of the longitudinal axis of the lubricating oil box (1).

9. The novel multifunctional integrated oil tank for a micro turbojet engine as claimed in claim 1, characterized in that: The filter assembly (5) is provided with a defoaming plate, which is capable of completely covering the cross section of the lubricating oil box (1), and the defoaming plate is provided with a plurality of perforations.

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