Transmission structure for enhancing fluid circulation between aero-engine cavities

Abstract

The invention relates to the technical field of aero-engines, and discloses a transmission structure for enhancing fluid circulation between aero-engine cavities, which comprises a casing body, and the casing body is sealed by a casing cover to form a cavity B; an engine front fulcrum bearing cavity is a cavity A and located outside a casing cover, a gear is arranged in the casing cover, the gear transmits mechanical torque rotation through a spline torque transmission shaft, a connecting piece is fixedly arranged on the gear towards the cavity A, a plurality of vent holes are formed in the connecting piece, and an oil-gas mixture channel is formed by gaps among the vent holes, the gear and the inner wall of the casing body and an opening of the casing body. A plurality of spiral grooves are formed in the gear back, facing the channel, of the gear, and the spiral grooves and the gear rotate in the same or opposite direction; when the spline torque transmission shaft drives the gear to operate, a rainbow effect is formed through the spiral groove. The structure is simple, and the compactness and reliability of the engine can be greatly improved by enhancing the fluid circulation structure between the cavities without a too large circulation sectional area.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and in particular to a transmission structure for enhancing fluid flow between chambers of an aeroengine. Background Art

[0002] The lubricating oil system of an aircraft engine continuously delivers clean lubricating oil to various components of the engine, reduces friction, and cleans up debris. It is the key to ensure the normal operation of the engine, and it has an important impact on engine performance and even safety. The key components of the lubricating oil system of an aircraft engine include the supply / return oil pump, the fuel oil radiator, the oil-gas separation mechanism, etc. At present, in order to improve the oil-gas separation effect of aircraft engines, most of the research is mainly based on the active oil-gas separation mechanism, which is mainly reflected in the use of materials with good adsorption properties to improve oil-gas separation, and the weight reduction effect on the engine is not significant; the lubricating oil system is a relatively complex structure, including a large number of functional components, pipelines, and accessory transmission systems that provide power to various functional accessories. In order to adapt to the continuously increasing thrust-to-weight ratio requirements of advanced engines, the lubricating oil system needs to reduce its own complexity, reduce weight, and improve working reliability. However, there is little research on the optimization of the circulation pipeline design. It should be optimized in the design link to reduce the application of connecting pipelines, avoid cumbersome connecting pipelines, and improve the safety of the lubricating oil system.

[0003] The moving parts such as gears and bearings in the aircraft engine will generate a lot of heat during high-speed operation, and need to continuously use lubricating oil for circulating heat dissipation and lubrication. During the circulation and lubrication of lubricating oil, a large amount of oil mist and gas-gas mixture will be generated inside the cavity, which will have a certain impact on the heat dissipation of lubricating oil and internal pressure of the chamber. Therefore, it is necessary to use corresponding devices to separate the oil and gas of the engine. Usually, the aircraft engine will only arrange the oil and gas separation device in one of the chambers, and the oil and gas in the other chambers need to flow to the device with the oil and gas separation device through a pipeline / channel with a certain cross-sectional area. In order to ensure the balance of pressure in each chamber of the aircraft engine and meet the requirements of fluid (oil and gas) circulation between chambers, the method usually adopted is to design a pipeline / channel with a large enough cross-sectional area according to the ventilation volume. As long as the cross-sectional area between the chambers is large enough, the pressure balance of the chamber can be guaranteed. In some advanced aircraft engine fields, the structural size / weight requirements are limited, and it is often impossible to ensure a large enough cross-sectional area pipeline / channel between the chambers. In other words, designing a channel that is too large will make the engine structure not compact enough, sacrifice the space size, and at the same time increase the weight of the engine. Summary of the invention

[0004] In order to overcome or alleviate one or more of the above technical problems, the purpose of the present invention is to provide a transmission structure for enhancing fluid circulation between aircraft engine chambers. The structure is used to enhance the circulation of fluid (oil-gas mixture) between aircraft engine chambers. It utilizes existing structural parts of aircraft engines and is designed to have a simple structure. The structure enhances the circulation of fluid between chambers. It does not require a large circulation cross-sectional area, thereby greatly improving the compactness and reliability of the engine.

[0005] The present invention provides the following technical solutions:

[0006] A transmission structure for enhancing fluid flow between chambers of an aircraft engine, comprising a casing body (1), the casing body (1) being sealed by a casing cover (9) to form a B chamber; a front fulcrum bearing chamber of the engine being an A chamber, which is located outside the casing cover (9); a gear being arranged in the casing cover (9); the gear transmitting mechanical torque to rotate through a spline torque transmission shaft (5); a connecting piece being fixedly arranged on the gear facing the A chamber, the connecting piece being provided with a plurality of vents (11); the vents (11), the gap between the gear and the inner wall of the casing body (1) and the opening of the casing body (1) forming a passage for an oil-gas mixture; a plurality of spiral grooves (10) being arranged on the wheel back of the gear facing the passage, the spiral grooves (10) rotating in the same direction or in the opposite direction to the gear; when the spline torque transmission shaft (5) drives the gear to rotate, a rainbow effect is formed through the spiral grooves (10).

[0007] According to some embodiments, the gear is selected from a bevel gear (8) or a cylindrical gear; the connecting member includes a bearing (2) and a bearing seat (3), the bearing (2) surrounds and supports the bevel gear (8), and the bearing seat (3) is arranged at the lower end of the bearing (2); and a plurality of ventilation holes (11) are evenly distributed on the bearing seat (3).

[0008] According to some embodiments, the distribution of the ventilation holes (11) is selected from a multi-hole dense distribution or a waist-shaped hole large flow area distribution.

[0009] According to some embodiments, the number of the ventilation holes (11) is 1 to 3 times the number of the spiral grooves (10).

[0010] According to some embodiments, an adjustment pad (7) for adjusting the axial direction of the bevel gear (8) is provided below the back of the bevel gear (8).

[0011] According to some embodiments, the first sealing rubber ring (4) is arranged between the spline torque transmission shaft (5) and the gear; and the second sealing rubber ring (6) is arranged between the bearing seat (3) and the casing body (1).

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1) The present invention provides a transmission structure for enhancing fluid flow between chambers of an aircraft engine. The spoke plate of the gear structure of the transmission structure is provided with a spiral groove, and the rotation direction of the spiral groove is the same as that of the bevel gear, so that the oil-gas mixture in the A chamber can flow to the bearing seat more easily; at the same time, the bottom of the bearing seat is provided with a multi-pore dense structure or a plurality of large-pore distribution structures, such as the attached Figure 3 As shown, this porous structure can improve the flow efficiency of the oil-gas mixture from cavity A to cavity B. This method of enhancing fluid flow between the chambers of the aircraft engine breaks the traditional design idea that flow can only be ensured by increasing the flow area;

[0014] 2) The present invention utilizes the structural characteristics of existing rotating parts and proposes to open spiral grooves on the spokes of gears, not limited to bevel gears. Although the strength of a part of the gears will be sacrificed, the problem of weakened strength can be solved through strength verification. The high-speed spiral grooves disturb the fluid, thereby affecting the circulation of the fluid in the chamber, thereby achieving the effect of enhancing the circulation;

[0015] 3) The present invention designs annularly arranged vent holes on the bearing seat, which usually have two forms, a multi-hole dense distribution structure and a waist-shaped hole large flow area layout structure; the flow efficiency is improved by matching the vent holes with the spiral grooves (usually in a multiple relationship).

[0016] 4) According to the actual needs of the engine, the spiral groove can be designed in reverse direction to achieve the reverse flow of the fluid;

[0017] 5) The number, size and depth of the spiral grooves on the gear affect the effect of enhancing fluid circulation. The parameters can be designed and selected according to actual needs, and the strength of the gear needs to be considered. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A cross-sectional view of a transmission structure for enhancing fluid flow between chambers of an aircraft engine provided by an embodiment of the present invention.

[0019] Figure 2 A schematic diagram of a spiral groove provided on a bevel gear according to an embodiment of the present invention.

[0020] Figure 3 A schematic diagram of a bearing seat with a vent hole provided in an embodiment of the present invention.

[0021] In the figure:

[0022] 1. Casing body; 2. Bearing; 3. Bearing seat; 4. First sealing rubber ring; 5. Spline torque transmission shaft; 6. Second sealing rubber ring; 7. Adjustment pad; 8. Bevel gear; 9. Casing cover; 10. Spiral groove; 11. Vent hole. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Example 1

[0026] like Figure 1 This embodiment provides a transmission structure for enhancing fluid circulation between chambers of an aircraft engine, so as to enhance fluid circulation between chambers, hereinafter referred to as the transmission structure.

[0027] The transmission structure includes a casing body 1, and the casing body 1 and the casing cover 9 form a closed space to form a B cavity, which is an aircraft engine accessory transmission cavity, and an A cavity is an engine front pivot bearing cavity (its closed structure is not shown in the attached figure). Both the A cavity and the B cavity contain an oil-gas mixture, and the A cavity is located below the B cavity. The solid points in the figure are used to simulate the oil-gas mixture.

[0028] A bevel gear 8 is provided in the casing cover 9, and the bevel gear 8 is driven to rotate by the spline torque transmission shaft 5 provided at the lower end thereof. The bearing 2 supports the bevel gear 8 in a lower ring shape, and the bearing seat 3 is fixedly provided at the lower end of the bearing 2. The A chamber and the B chamber are connected via the bearing seat 3; in addition, part of the engine power is transmitted to various parts of the B chamber through the spline torque transmission shaft 5 of the A chamber and the bevel gear 8 connected to the B chamber; the bearing 2 is used to support the bevel gear 8, and the adjustment pad 7 is provided under the back of the bevel gear 8 to adjust the axial position of the bevel gear 8; the first sealing rubber ring 4 is provided between the spline torque transmission shaft 5 and the bevel gear 8 to isolate the A chamber and the B chamber, and at the same time obtain a damping effect on the spline torque transmission shaft 5. The second sealing rubber ring 6 is provided between the bearing seat 3 and the casing body 1 to prevent the lubricating oil of the B chamber from leaking to the outside;

[0029] Due to structural limitations, the cross-sectional area of ​​the channel connecting cavity A and cavity B is limited. Figure 3 The bearing seat 3 is evenly distributed with a number of vent holes 11 in the circumferential direction. The oil-gas mixture in the A cavity enters the channel between the inner wall of the casing 1 and the bearing 2 from the vent holes 11, and enters the A cavity from the lower side of the back of the bevel gear 8 and the opening of the casing 1. At the same time, a spiral groove 10 is designed on the back of the bevel gear 8, and the rotation direction of the spiral groove 10 is consistent with the rotation direction of the bevel gear 8.

[0030] During the operation of the engine, the spline torque transmission shaft 5 drives the spiral bevel gear 8 to rotate at high speed. The bevel gear 8 forms a siphon effect through the spiral groove 10 on its spoke plate, thereby improving the efficiency of the oil-gas mixture passing through the vent hole 11 on the bearing seat 3, thereby enhancing the efficiency of the lubricating oil-gas mixture flowing from cavity A to cavity B. Tests have shown that when the rotation speed is ≥20000r / min, the circulation efficiency is increased to 320%, meeting the pressure balance requirements of the engine chamber.

[0031] like Figure 2 ,in Figure 2 .a is the cross-sectional view of the bevel gear, Figure 2 .b is a bevel gear with multiple spiral grooves 10.

[0032] like Figure 3 ,in Figure 3 .a is a cross-sectional view of the bearing seat 3, Figure 3 .b is a schematic diagram of a multi-hole density distribution structure in which a plurality of smaller and denser ventilation holes 11 are evenly arranged on the bearing seat 3, Figure 3 .c is a layout structure in which four waist-shaped ventilation holes 11 are evenly arranged on the bearing seat 3, and the waist-shaped holes have a larger flow area.

[0033] There are also the following points to note:

[0034] 1. The rotation direction of the bevel gear 8 and the rotation direction of the spiral groove 10 affect the flow direction of the oil-gas mixture. If the directions are the same, the oil-gas mixture is more likely to flow to the chamber A where the bevel gear 8 is located. Figure 1 As shown; if the direction is opposite, the oil-gas mixture is more likely to flow to the vent hole 11 of the bearing seat 3.

[0035] 2. By designing the rotation direction of the spiral groove 10, the required oil and gas flow direction can be achieved, that is, whether cavity A flows to cavity B or cavity B flows to cavity A.

[0036] 3. The number and size of the spiral grooves 10 on the gear must match the vent holes 11 of the bearing seat 3, which are generally in multiples. The vent holes are 1 to 3 times the number of spiral grooves; this will result in higher efficiency.

[0037] 4. The gear is not limited to bevel gear 8, and it is not limited to bevel gears here, but can also be cylindrical gears, as long as two conditions are met: first, there is space on the spoke plate to open a spiral groove; second, the spoke plate and the ventilation channel form a narrow channel; a spiral groove 10 is opened on the back of the high-speed rotating gear tooth, and the design matches the bearing seat, and the effect remains unchanged.

[0038] 5. Since the gear spoke plate has a spiral groove 10, it is necessary to perform strength check. In addition, no sharp edges are left around the spiral groove 10 to avoid stress concentration.

[0039] 6. The bearing seat 3 can also be a general connecting piece, which has nothing to do with whether the bearing 2 is installed, and mainly depends on the vent hole 11 provided on the connecting piece.

[0040] In this embodiment, the spiral groove 10 of the bevel gear 8 and the bearing seat 3 are integrated, and the traditional method of ensuring circulation by increasing the circulation area is changed without adding additional parts. The flow rate of the oil-gas mixture is increased by setting the vent hole 11 and the spiral groove 10. Tests show that the circulation efficiency is increased to 320% when the rotation speed is ≥ 20000r / min. The engine space is saved, the size and weight of the parts are reduced, and the pressure balance capacity of the engine chamber is effectively enhanced. The structure is compact, the economy is good, the maintenance cost is low, and the reliability is high.

[0041] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A transmission structure for enhancing fluid flow between chambers of an aircraft engine, comprising a casing body (1), the casing body (1) being sealed by a casing cover (9) to form a B chamber; the engine front fulcrum bearing chamber is a A chamber, which is located outside the casing cover (9), the casing cover (9) is provided with a gear, the gear transmits mechanical torque to rotate through a spline torque transmission shaft (5), and is characterized in that: The gear is fixedly provided with a connecting piece facing the A cavity, and the connecting piece is provided with a plurality of vent holes (11), and the vent holes (11), the gap between the gear and the inner wall of the casing body (1), and the opening of the casing body (1) form a passage for the oil-gas mixture; a plurality of spiral grooves (10) are provided on the wheel back of the gear facing the passage, and the spiral grooves (10) rotate in the same direction or in the opposite direction to the gear; when the spline torque transmission shaft (5) drives the gear to rotate, a rainbow effect is formed through the spiral grooves (10).

2. The transmission structure for enhancing fluid flow between chambers of an aircraft engine according to claim 1, characterized in that: The gear is selected from a bevel gear (8) or a cylindrical gear; the connecting member comprises a bearing (2) and a bearing seat (3); the bearing (2) surrounds and supports the bevel gear (8); the bearing seat (3) is arranged at the lower end of the bearing (2); and a plurality of ventilation holes (11) are evenly distributed on the bearing seat (3).

3. The transmission structure for enhancing fluid flow between chambers of an aircraft engine according to claim 2, characterized in that: The distribution of the ventilation holes (11) is selected from a multi-hole dense distribution or a waist-shaped hole large flow area distribution.

4. The transmission structure for enhancing fluid flow between chambers of an aircraft engine according to claim 2, characterized in that: The number of the vent holes (11) is 1 to 3 times the number of the spiral grooves (10).

5. The transmission structure for enhancing fluid flow between chambers of an aircraft engine according to claim 2, characterized in that: An adjustment pad (7) for adjusting the axial direction of the bevel gear (8) is provided below the back of the bevel gear (8).

6. The transmission structure for enhancing fluid flow between chambers of an aircraft engine according to claim 5, characterized in that: The first sealing rubber ring (4) is arranged between the spline torque transmission shaft (5) and the gear; and the second sealing rubber ring (6) is arranged between the bearing seat (3) and the casing body (1).

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