Aircraft engine exhaust pipe

Abstract

The present invention discloses an aircraft engine exhaust pipe in the technical field of aircraft turboshaft engine exhaust system. The present invention installs an inner pipe in an outer pipe, and arranges an oil collecting passage in the inner pipe, so that the ventilation airflow entering the exhaust pipe enters the oil collecting passage and is discharged after passing through the oil collecting passage. The oil collecting passage comprises a short pipe and an oil collecting hood. When the ventilation airflow enters the short pipe and the oil collecting hood, the lubricating oil carried by the ventilation airflow will adhere to the inner cavity of the short pipe and the inner cavity of the oil collecting hood, and the lubricating oil attached to the inner cavity of the short pipe and the oil collecting hood can be gathered at the bottom of the inner cavity of the oil collecting hood through the ventilation airflow and gravity, and then the lubricating oil is discharged from the oil collecting hood through the oil drain port and enters the oil drain pipe to collect the lubricating oil uniformly and reuse it, and the ventilation airflow entering the exhaust pipe is separated from oil and gas again, which can not only reduce the adhesion of the lubricating oil to the inner cavity surface of the outer pipe and the outer wall surface of the inner pipe, thereby reducing the risk of fire, but also can recycle the lubricating oil and reduce oil consumption.

Description

Technical Field

[0001] The invention relates to the technical field of aviation turboshaft engine exhaust systems, in particular to an aviation engine exhaust pipe. Background Art

[0002] During the operation of the engine, the internal cavity needs to be ventilated. Before the ventilation airflow is discharged from the engine, the oil and gas need to be separated, the lubricating oil needs to be recovered, and the gas needs to be discharged into the atmosphere.

[0003] At present, an oil-gas separation device is provided at the front end of the engine to separate the lubricating oil in the ventilation airflow. However, in this process, it is difficult to completely separate the oil and gas, and it is inevitable that part of the lubricating oil will be discharged from the engine exhaust pipe along with the gas. At present, there is no oil-gas separation structure in the engine exhaust pipe, which causes the ventilation airflow entering the exhaust pipe to be directly discharged with the lubricating oil, resulting in the consumption of the lubricating oil. Moreover, this part of the lubricating oil may accumulate in the oil-accumulating structure of the exhaust pipe, thereby causing the lubricating oil to coke and even cause a fire, which is harmful to the safe operation of the engine.

[0004] Therefore, measures need to be taken to collect as much lubricating oil as possible and return it to the oil circuit or lubricating oil tank to minimize the amount of lubricating oil discharged with the air.

[0005] Based on this, the present invention designs an aircraft engine exhaust pipe to solve the above problems. Summary of the invention

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an aircraft engine exhaust pipe, comprising an outer pipe, an inner pipe and an oil collecting passage;

[0007] The inner tube and the outer tube are both rotating bodies, and a plurality of support plates are fixedly arranged in the outer tube, and the plurality of support plates are arranged along the circumference of the outer tube, and the inner tube is fixedly arranged at one end of the support plate away from the outer tube, so that the inner tube is fixed in the outer tube and is coaxially arranged with the outer tube, and the diameter of the inner tube is smaller than the diameter of the outer tube, so that a flow channel of the mainstream of the engine is formed between the outer tube and the inner tube for the flow of the air discharged from the turbine;

[0008] The oil collecting passage includes a short tube, an oil collecting hood and an oil drain pipe, the short tube is fixedly arranged in the inner cavity of the inner tube, one end of the short tube faces the air inlet end of the inner tube, and is connected to a pipeline in the front end of the engine for discharging ventilation airflow, and the other end is fixedly connected to the oil collecting hood and is connected to the inner cavity of the oil collecting hood, an exhaust hole is provided on the top of the oil collecting hood, for discharging ventilation airflow entering the short tube from one end of the short tube away from the oil collecting hood, an oil drain port is provided at the vertical bottom of the oil collecting hood, the oil drain port is connected to an oil drain pipe for recovering lubricating oil, the interior of the support plate is hollow, and the oil drain pipe passes through the support plate from the inside of the support plate, thereby penetrating the inner tube and the outer tube.

[0009] As a further solution of the present invention, the short tube and the oil collecting hood are both rotating bodies, and the diameter of the short tube inner cavity near one end of the oil collecting hood is smaller than the diameter of the oil collecting hood inner cavity, so as to form a step at the connection position between the short tube and the oil collecting hood.

[0010] As a further solution of the present invention, the end of the short tube inner cavity away from the oil collecting hood is bent toward the axis of the short tube to form a protrusion for preventing the lubricating oil from leaving the short tube from the end of the short tube away from the oil collecting hood.

[0011] As a further solution of the present invention, the inner diameter of the end of the short tube close to the oil collecting hood is larger than the inner diameter of the end away from the oil collecting hood.

[0012] As a further solution of the present invention, a baffle is fixedly provided in the inner cavity of the oil collecting hood, and the baffle is used to block the side of the exhaust port close to the short tube and directly below the exhaust port, so that the ventilation airflow entering the oil collecting hood from the short tube can bypass the baffle before leaving the oil collecting hood from the exhaust port.

[0013] As a further solution of the present invention, both ends of the baffle in a first direction are tilted or bent downward, and the first direction is perpendicular to the central axis of the oil collecting hood and parallel to the horizontal plane.

[0014] As a further solution of the present invention, an end plate is fixedly provided at the air inlet end of the inner tube, and the end plate is used to close the air inlet end of the inner tube; a mounting hole for installing a short tube is opened in the center of the end plate, and the short tube is fixed in the mounting hole, and one end of the short tube away from the oil collecting hood faces the air inlet end of the inner tube.

[0015] As a further solution of the present invention, the position of the end plate close to the short tube is recessed toward the gas outlet end of the inner tube.

[0016] As a further solution of the present invention, the inner diameter of the air inlet end of the outer tube is smaller than the inner diameter of the air outlet end of the outer tube, and the inner diameter of the air inlet end of the inner tube is larger than the inner diameter of the air outlet end of the inner tube, so that the air flow channel formed between the inner tube and the outer tube is in an expanded state.

[0017] As a further solution of the present invention, the air inlet end of the outer tube is provided with a mounting edge, and the wall thickness of the outer tube main body, the support plate and the inner tube are all smaller than the wall thickness of the mounting edge.

[0018] The present invention has the following beneficial effects:

[0019] The present invention installs an inner tube in an outer tube and provides an oil collecting passage in the inner tube, so that the ventilation airflow entering the exhaust pipe enters the oil collecting passage and is discharged after passing through the oil collecting passage. The main flow channel between the inner tube and the outer tube is used to circulate the main airflow, and the oil collecting passage does not interfere with the main airflow in the main flow channel. The oil collecting passage includes a short tube and an oil collecting hood. When the ventilation airflow enters the short tube and the oil collecting hood, the lubricating oil carried by the ventilation airflow will adhere to the inner cavity of the short tube and the inner cavity of the oil collecting hood, and the lubricating oil attached to the inner cavity of the short tube and the oil collecting hood can be gathered at the bottom of the inner cavity of the oil collecting hood through the ventilation airflow and gravity, and then the lubricating oil is discharged from the oil collecting hood through the oil drain port and enters the oil drain pipe to collect the lubricating oil uniformly and reuse it, and the ventilation airflow entering the exhaust pipe is separated from oil and gas again, which can not only reduce the adhesion of the lubricating oil to the inner cavity surface of the outer tube and the outer wall surface of the inner tube and reduce the risk of fire, but also can recycle the lubricating oil and reduce oil consumption.

[0020] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 Schematic diagram of the overall structure of the present invention;

[0023] Figure 2 A cross-sectional schematic diagram of the present invention;

[0024] Figure 3 A schematic diagram of the structure of the oil collecting passage in the present invention;

[0025] Figure 4 FF axial cross-sectional schematic diagram of the oil collecting cover of the present invention;

[0026] Figure 5 It is an enlarged schematic diagram of the installation edge in the present invention.

[0027] Legend:

[0028] 1. Outer tube; 11. Mounting edge; 2. Inner tube; 21. End plate; 3. Support plate; 41. Short tube; 42. Oil collecting cover; 43. Oil drain pipe; 44. Exhaust hole; 45. Oil drain port; 46. Protrusion; 47. Baffle; 48. Pipe joint. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0030] See also Figure 1-5 , the present invention provides a technical solution: an aircraft engine exhaust pipe, comprising an outer pipe 1, an inner pipe 2 and an oil collecting passage;

[0031] The inner tube 2 and the outer tube 1 are both rotating bodies, and a plurality of support plates 3 are fixedly arranged in the outer tube 1, and the plurality of support plates 3 are arranged along the circumferential direction of the outer tube 1. The inner tube 2 is fixedly arranged at one end of the support plate 3 away from the outer tube 1, so that the inner tube 2 is fixedly arranged in the outer tube 1 and is coaxially arranged with the outer tube 1. The diameter of the inner tube 2 is smaller than the diameter of the outer tube 1, so that a flow channel of the mainstream of the engine is formed between the outer tube 1 and the inner tube 2, which is used for the flow of the air discharged by the turbine;

[0032] The oil collecting passage comprises a short tube 41, an oil collecting cover 42 and an oil drain pipe 43. The short tube 41 is fixedly arranged in the inner cavity of the inner tube 2. One end of the short tube 41 faces the air inlet end of the inner tube 2 and is communicated with the pipeline in the front end of the engine for discharging ventilation airflow, and the other end is fixedly connected to the oil collecting cover 42 and communicated with the inner cavity of the oil collecting cover 42. An exhaust hole 44 is provided on the top of the oil collecting cover 42 for discharging the ventilation airflow entering the short tube 41 from the end of the short tube 41 away from the oil collecting cover 42. The oil collecting cover 42 is provided with an oil drain port 45 at the bottom in the vertical direction. The oil drain port 45 is connected to the oil drain pipe 43 for recovering lubricating oil. During the operation of the engine, the internal cavity needs to be ventilated. The ventilation airflow will eventually enter the short tube 41 from the end of the short tube 41 away from the oil collecting cover 42, and enter the oil collecting cover 42 after passing through the short tube 41. The top of the oil collecting cover 42 is provided with an exhaust hole 44, and the ventilation airflow that finally enters the oil collecting cover 42 can be discharged from the oil collecting cover 4 2 leaves the oil collecting hood 42. When the ventilation airflow passes through the short tube 41 and the oil collecting hood 42, the lubricating oil carried in the ventilation airflow will adhere to the inner cavity of the short tube 41 and the inner cavity of the oil collecting hood 42. The lubricating oil attached to the short tube 41 will be gathered in the oil collecting hood 42 driven by the ventilation airflow. At the same time, the lubricating oil attached to the inner cavity of the short tube 41 and the inner cavity of the oil collecting hood 42 will also gather downward under the action of gravity and finally all gather at the bottom of the inner cavity of the oil collecting hood 42. An oil drain port 45 is provided at the bottom of the inner cavity of the oil collecting hood 42. The lubricating oil gathered at the bottom of the inner cavity of the oil collecting hood 42 will leave the oil collecting hood 42 from the oil drain port 45 and enter the oil drain pipe 43 connected to the oil drain port 45. The end of the oil drain pipe 43 away from the oil collecting hood 42 is connected to the lubricating oil recovery pipeline through a pipe joint 48. The lubricating oil entering the oil drain pipe 43 will be downward along the oil drain pipe 43 under the action of gravity and finally enter the lubricating oil recovery pipeline for recovery and reuse.

[0033] The present invention installs an inner tube 2 in an outer tube 1 and provides an oil collecting passage in the inner tube 2, so that the ventilation airflow entering the exhaust pipe enters the oil collecting passage and is discharged after passing through the oil collecting passage. The oil collecting passage includes a short tube 41 and an oil collecting hood 42. When the ventilation airflow enters the short tube 41 and the oil collecting hood 42, the lubricating oil carried by the ventilation airflow will adhere to the inner cavity of the short tube 41 and the inner cavity of the oil collecting hood 42, and the lubricating oil attached to the inner cavity of the short tube 41 and the inner cavity of the oil collecting hood 42 can be gathered at the bottom of the inner cavity of the oil collecting hood 42 through the ventilation airflow and gravity, and then the lubricating oil is discharged from the oil collecting hood 42 through the oil drain port 45 and enters the oil drain pipe 43, where the lubricating oil is uniformly collected and reused, which can not only reduce the adhesion of the lubricating oil to the inner cavity surface of the outer tube 1 and the outer wall surface of the inner tube 2 and reduce the risk of fire, but also recycle the lubricating oil and reduce oil consumption.

[0034] Furthermore, the support plate 3 is hollow inside, thereby reducing the weight of the entire exhaust pipe. Figure 2 As shown, the oil drain pipe 43 can pass through the support plate 3 from the inside of the support plate 3, thereby penetrating the inner tube 2 and the outer tube 1;

[0035] Further, such as Figure 3 As shown, the short tube 41 and the oil collecting cover 42 are both rotating bodies, and the diameter of the inner cavity of the short tube 41 near the end of the oil collecting cover 42 is smaller than the inner cavity diameter of the oil collecting cover 42, so as to form a step at the connection position between the short tube 41 and the oil collecting cover 42. When the lubricating oil in the oil collecting cover 42 moves toward the short tube 41, it needs to cross the step, and the lubricating oil in the oil collecting cover 42 is blocked from moving into the short tube 41 by the step.

[0036] By controlling the height difference between the adjacent positions of the short tube 41 and the oil collecting hood 42, a step is formed at the adjacent positions of the short tube 41 and the oil collecting hood 42. When the lubricating oil in the short tube 41 moves into the oil collecting hood 42, it can move downward along the step, and can easily move from the short tube 41 to the oil collecting pipe. When the lubricating oil in the oil collecting pipe needs to move into the short tube 41, it needs to move upward along the step. The step can block the lubricating oil in the oil collecting pipe from moving into the short tube 41, so as to prevent the lubricating oil in the oil collecting hood 42 from moving into the short tube 41 when the engine attitude is tilted.

[0037] Further, such as Figure 3 As shown, the end of the inner cavity of the short tube 41 away from the oil collecting cover 42 is bent toward the axis of the short tube 41 to form a protrusion 46, which is used to prevent the lubricating oil from leaving the short tube 41 from the end of the short tube 41 away from the oil collecting cover 42. When the lubricating oil attached to the inner cavity of the short tube 41 moves toward the end of the short tube 41 away from the oil collecting cover 42, the protrusion 46 can block the lubricating oil from leaving the short tube 41, preventing the lubricating oil in the short tube 41 from leaving the short tube 41 from the opening of the short tube 41, and can prevent the lubricating oil in the short tube 41 from flowing out to a certain extent.

[0038] A protrusion 46 facing the central axis of the short tube 41 is provided at one end of the inner cavity of the short tube 41 away from the oil collecting cover 42, and the protrusion 46 is used to prevent the lubricating oil in the short tube 41 from moving out of the short tube 41. Before the liquid level of the lubricating oil in the short tube 41 exceeds the protrusion 46, the lubricating oil in the short tube 41 will not be able to leave the short tube 41 from the end of the short tube 41 away from the oil collecting cover 42, so as to prevent the lubricating oil in the short tube 41 from flowing out of the short tube 41 when the engine attitude is tilted.

[0039] Further, such as Figure 3 As shown, the inner diameter of the end of the short tube 41 close to the oil collecting cover 42 is larger than the inner diameter of the end away from the oil collecting cover 42, so that the inner cavity of the short tube 41 is truncated, and the end of the inner cavity of the short tube 41 with a smaller inner diameter is away from the oil collecting cover 42. Therefore, when the ventilation airflow passes through the short tube 41 and the lubricating oil is attached to the inner cavity of the short tube 41, under the action of gravity, the lubricating oil attached to the inner cavity of the short tube 41 will slide toward the direction of the oil collecting cover 42. Under the dual action of gravity and ventilation airflow, the lubricating oil in the short tube 41 can move faster into the oil collecting cover 42 and enter the oil drain pipe 43 for circulation faster.

[0040] By controlling the shape of the inner cavity of the short tube 41, the inner cavity of the short tube 41 is made to be truncated cone-shaped, and the end with a smaller inner diameter of the inner cavity of the short tube 41 is away from the oil collecting hood 42, and the end with a larger inner diameter is connected to the oil collecting hood 42. When the lubricating oil adheres to the inner cavity of the short tube 41, under the action of gravity, the lubricating oil will move to the bottom end of the short tube 41, and will also move in the direction of the oil collecting hood 42. Combined with the ventilation airflow entering from the end of the short tube 41 away from the oil collecting hood 42, the lubricating oil adhered to the inner cavity of the short tube 41 can be quickly moved into the oil collecting hood 42, thereby shortening the moving time of the lubricating oil in the short tube 41 and allowing the lubricating oil to enter the oil drain pipe 43 more quickly for recovery.

[0041] Furthermore, a baffle 47 is fixedly provided in the inner cavity of the oil collecting hood 42, and the baffle 47 is used to block the side of the exhaust port close to the short tube 41 and directly below the exhaust port, so that the ventilation airflow entering the oil collecting hood 42 from the short tube 41 can bypass the baffle 47 before leaving the oil collecting hood 42 from the exhaust port. Figure 3As shown, the baffle 47 is fixed to the top of the inner cavity of the oil collecting hood 42, and the other end of the baffle 47 is fixed to the end of the oil collecting hood 42 axially away from the short tube 41. In this way, the baffle 47 realizes the enclosure of the exhaust port from the bottom of the exhaust port. When the ventilation airflow enters the oil collecting hood 42, it will move along the axial direction of the oil collecting hood 42. At the same time, the exhaust port is opened at the top of the oil collecting hood 42. Among the ventilation airflow entering the oil collecting hood 42, part of the airflow located at the top can directly move toward the exhaust port and enter the exhaust port, while the remaining airflow can be directly moved to the exhaust port. The airflow will move upwards into the exhaust port after entering the oil collecting hood 42, and the baffle 47 blocks the path of the ventilation airflow entering the exhaust port. If the ventilation airflow needs to enter the exhaust port, it must bypass the baffle 47 from both sides of the baffle 47 to prevent the ventilation airflow from leaving the oil collecting hood 42 directly from the exhaust port and directly taking out the lubricating oil. When the ventilation airflow bypasses the baffle 47, the lubricating oil carried by the ventilation airflow will contact the baffle 47 and adhere to the baffle 47, which can improve the collection rate of the lubricating oil and reduce the consumption of the lubricating oil.

[0042] The exhaust port is blocked by the baffle 47, so that the ventilation airflow entering the oil collecting hood 42 cannot leave directly from the exhaust port, and must bypass the baffle 47 before leaving the oil collecting hood 42 from the exhaust port. When the ventilation airflow bypasses the baffle 47, the lubricating oil carried by the ventilation airflow will contact the baffle 47 and adhere to the surface of the baffle 47, preventing the ventilation airflow from carrying the lubricating oil directly out of the exhaust port, thereby improving the collection rate of the lubricating oil and reducing the consumption of the lubricating oil.

[0043] Further, such as Figure 3-4 As shown, the two ends of the baffle 47 in the first direction are tilted or bent downward, and the first direction is perpendicular to the central axis of the oil collecting hood 42 and parallel to the horizontal plane. When the ventilation airflow bypasses the baffle 47 and leaves the oil collecting hood 42 from the exhaust port above the baffle 47, the lubricating oil carried in the ventilation airflow will adhere to the upper surface of the baffle 47. When the two ends of the baffle 47 are tilted or bent downward, the lubricating oil attached to the upper surface of the baffle 47 can slide downward along the baffle 47, and then leave the baffle 47 and drip to the bottom end of the oil collecting hood 42. At the same time, the lubricating oil attached to the bottom end of the baffle 47 can also slide downward along the baffle 47 to leave the baffle 47, accelerating the departure of the lubricating oil from the baffle 47 to prevent excessive lubricating oil from adhering to the baffle 47 and affecting the efficiency of the subsequent baffle 47 in collecting the lubricating oil.

[0044] The first direction is the X direction;

[0045] Figure 4 An example of the baffle 47 is shown. In this example, the baffle 47 is arc-shaped, the arc opening of the baffle 47 faces downward, and the baffle 47 is coaxially arranged with the oil collecting cover 42. Figure 4As shown, when lubricating oil is attached to the surface of the baffle 47, the lubricating oil will move to the two ends of the baffle 47 in the X direction under the action of gravity, and finally leave the baffle 47 from the two ends of the baffle 47 in the X direction, drip and be collected to the bottom end of the oil collecting cover 42, so that the lubricating oil attached to the baffle 47 can leave the baffle 47 faster, preventing excessive lubricating oil from accumulating on the baffle 47 and affecting the collection efficiency of the baffle 47 for the lubricating oil.

[0046] Further, such as Figure 2-3 As shown, the air inlet end of the inner tube 2 is fixedly provided with an end plate 21, and the end plate 21 is used to close the air inlet end of the inner tube 2; a mounting hole for mounting a short tube 41 is opened in the center of the end plate 21, and the short tube 41 is fixedly arranged in the mounting hole, and the end of the short tube 41 away from the oil collecting cover 42 faces the air inlet end of the inner tube 2. The ventilation airflow in the engine will be discharged from the exhaust pipe after passing through the engine. The end plate 21 is arranged at the air inlet end of the inner tube 2, and the air inlet end of the inner tube 2 is closed, so that the front end parts are in a semi-enclosed working environment;

[0047] The air inlet of the inner tube 2 is blocked by the end plate 21 to close the air inlet end of the inner tube 2, thereby placing the front end parts of the inner tube 2 in a semi-enclosed space to ensure the working environment of the front end parts of the inner tube 2.

[0048] Further, such as Figure 2-3 As shown, the position of the end plate 21 near the short tube is recessed toward the gas outlet end of the inner tube, and the space required for installing the components at the front end of the inner tube 2 is provided through the concession portion of the end plate 21, while enhancing the strength of the end plate 21;

[0049] Further, such as Figure 1 As shown, the inner diameter of the air inlet end of the outer tube 1 is smaller than the inner diameter of the air outlet end of the outer tube 1, and the inner diameter of the air inlet end of the inner tube 2 is larger than the inner diameter of the air outlet end of the inner tube 2, so that the air flow channel formed between the inner tube 2 and the outer tube 1 is in an expanded state, and the ventilation airflow entering the air flow channel between the outer tube 1 and the inner tube 2 from the inlet end of the outer tube 1 can be decelerated and pressurized under the action of the expanded air flow channel, thereby increasing the turbine outlet back pressure and ensuring that the ventilation airflow is smoothly discharged from the engine;

[0050] By setting the airflow channel between the inner tube 2 and the outer tube 1 to an expanded state, the ventilation airflow entering the airflow channel can be decelerated and pressurized under the action of the airflow channel, so that the turbine outlet has sufficient back pressure.

[0051] Further, such as Figure 5As shown, the air inlet end of the outer tube 1 is provided with a mounting edge 11, and the wall thickness of the main part of the outer tube 1, the support plate 3 and the inner tube 2 are all smaller than the wall thickness of the mounting edge 11. The mounting edge 11 is used to mount the outer tube 1 on the engine. In order to ensure the installation stability, the wall thickness of the mounting edge 11 cannot be too thin, and the wall thickness of the main part of the outer tube 1, the inner tube 2 and the support plate 3 are all smaller than the mounting edge 11, so as to ensure that when the turbine blades fall off and hit the exhaust pipe, only the wall surface of these parts with smaller thicknesses can be damaged, and large stress will not be directly applied to the mounting edge 11 and the whole circle of mounting bolts, so as to prevent the mounting edge 11 or the whole circle of bolts from breaking, thereby causing the entire exhaust pipe to fall off, thereby improving the safety of the exhaust pipe;

[0052] By implementing a containment design in the main part of the exhaust pipe, when a broken or detached turbine blade hits the exhaust pipe during use, the wall of the exhaust pipe will be damaged, thereby achieving a force unloading effect, preventing stress from directly acting on the mounting edge 11 and the entire circle of mounting bolts, causing the mounting edge 11 or the entire circle of bolts to break, thereby improving the safety of the exhaust pipe.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aircraft engine exhaust pipe, characterized in that: It comprises an outer tube (1), an inner tube (2) and an oil collecting passage; The inner tube (2) and the outer tube (1) are both rotating bodies, and a plurality of support plates (3) are fixedly arranged inside the outer tube (1), and the plurality of support plates (3) are arranged along the circumference of the outer tube (1). The inner tube (2) is fixedly arranged at one end of the support plate (3) away from the outer tube (1), so that the inner tube (2) is fixedly arranged inside the outer tube (1) and is coaxially arranged with the outer tube (1). The diameter of the inner tube (2) is smaller than the diameter of the outer tube (1), so that a flow channel of the mainstream of the engine is formed between the outer tube (1) and the inner tube (2), and is used for the flow of the air discharged by the turbine to flow; The oil collecting passage comprises a short tube (41), an oil collecting cover (42) and an oil drain pipe (43); the short tube (41) is fixedly arranged in the inner cavity of the inner tube (2); one end of the short tube (41) faces the air inlet end of the inner tube (2) and is connected to a pipeline in the front end of the engine for discharging ventilation airflow; the other end is fixedly connected to the oil collecting cover (42) and is connected to the inner cavity of the oil collecting cover (42); an exhaust hole (44) is provided at the top of the oil collecting cover (42) for discharging ventilation airflow entering the short tube (41) from the end of the short tube (41) away from the oil collecting cover (42); an oil drain port (45) is provided at the bottom of the oil collecting cover (42) in the vertical direction; the oil drain port (45) is connected to the oil drain pipe (43) for recovering lubricating oil; The interior of the support plate (3) is in a hollow state, and the oil discharge pipe (43) passes through the support plate (3) from the interior of the support plate (3), thereby penetrating the inner pipe (2) and the outer pipe (1).

2. The aircraft engine exhaust pipe according to claim 1, characterized in that: The short tube (41) and the oil collecting hood (42) are both rotating bodies, and the diameter of the inner cavity of the short tube (41) close to one end of the oil collecting hood (42) is smaller than the inner cavity diameter of the oil collecting hood (42), so as to form a step at the connection position between the short tube (41) and the oil collecting hood (42).

3. The aircraft engine exhaust pipe according to claim 1, characterized in that: The end of the inner cavity of the short tube (41) away from the oil collecting cover (42) is bent toward the axis of the short tube (41) to form a protrusion (46) for preventing lubricating oil from leaving the short tube (41) from the end of the short tube (41) away from the oil collecting cover (42).

4. The aircraft engine exhaust pipe according to claim 2, characterized in that: The inner diameter of the end of the short tube (41) close to the oil collecting cover (42) is larger than the inner diameter of the end away from the oil collecting cover (42).

5. The aircraft engine exhaust pipe according to claim 1, characterized in that: A baffle (47) is fixedly disposed in the inner cavity of the oil collecting hood (42), and the baffle (47) is used to shield a side of the exhaust port close to the short tube (41) and directly below the exhaust port, so that the ventilation airflow entering the oil collecting hood (42) from the short tube (41) can bypass the baffle (47) before leaving the oil collecting hood (42) from the exhaust port.

6. The aircraft engine exhaust pipe according to claim 5, characterized in that: The baffle (47) is tilted or bent downward at both ends in a first direction, and the first direction is perpendicular to the central axis of the oil collecting cover (42) and parallel to the horizontal plane.

7. The aircraft engine exhaust pipe according to claim 1, characterized in that: An end plate (21) is fixedly provided at the air inlet end of the inner tube (2), and the end plate (21) is used to close the air inlet end of the inner tube (2); A mounting hole for mounting a short tube (41) is provided at the center of the end plate (21); the short tube (41) is fixedly arranged in the mounting hole, and one end of the short tube (41) away from the oil collecting cover (42) faces the air inlet end of the inner tube (2).

8. The aircraft engine exhaust pipe according to claim 7, characterized in that: The position of the end plate (21) close to the short tube (41) is recessed toward the gas outlet end of the inner tube (2).

9. The aircraft engine exhaust pipe according to claim 1, characterized in that: The inner diameter of the air inlet end of the outer tube (1) is smaller than the inner diameter of the air outlet end of the outer tube (1), and the inner diameter of the air inlet end of the inner tube (2) is larger than the inner diameter of the air outlet end of the inner tube (2), so that the air flow channel formed between the inner tube (2) and the outer tube (1) is in an expanded state.

10. The aircraft engine exhaust pipe according to claim 1, characterized in that: The air inlet end of the outer tube (1) is provided with a mounting edge (11), and the wall thicknesses of the main body of the outer tube (1), the support plate (3) and the inner tube (2) are all smaller than the wall thickness of the mounting edge (11).

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