CN115030821A - Aeroengine bearing cavity labyrinth sealing structure - Google Patents

Abstract

A grate sealing structure for aero-engine bearing cavity, the bearing cavity is arranged between a main shaft and a casing, and is formed by a bearing inner ring, a bearing, an outer bearing ring, an oil scavenger ring and the grate sealing structure, The grate sealing structure is arranged on both sides of the bearing cavity along the axial direction. The grate sealing structure has a sealing stator and a sealing rotor that rotate relatively around the same axis. The sealing stator is sleeved on the outer side of the sealing rotor. The inner side of the sealing stator is provided with a sealing protection layer, the outer side of the sealing rotor is provided with a number of sealing grate teeth, the surface of the sealing protection layer is provided with at least one groove, and the depth of the groove is less than The thickness of the surface of the sealing protection layer.

Description

An aero-engine bearing cavity grate sealing structure

technical field

The invention belongs to the field of aero-engines, and in particular relates to a grate sealing structure for a bearing cavity and an aero-engine.

Background technique

In rotating machinery such as aero-engines, the gas leakage between the rotating parts of the main shaft of the bearing cavity, the stationary bushing, and the casing of the bearing cavity will lead to a decrease in the overall driving efficiency of the engine and an increase in the consumption of lubricating oil. For aero-engines, improving the sealing ability of this area, increasing the pressure difference between the front and rear of the sealing section and reducing the high temperature peripheral gas entering the bearing cavity from the sealing section can reduce the thermal load of the bearing cavity and reduce the consumption of lubricating oil, and the sealing ability It directly affects the performance parameters such as the fuel consumption rate and propulsion efficiency of the engine. Therefore, it is necessary to ensure a good sealing effect as much as possible.

As the most common sealing structure of aero-engines, the grate seal structure is widely used in various parts of the engine. The grate seal relies on the airflow from the high pressure area to pass through the narrow gaps formed by several grate teeth and the planar honeycomb structure. The cavity between the two grate teeth to achieve pressure reduction, thereby reducing leakage. When the air flows through the gap of the first grate, the flow rate increases and the pressure decreases; when it flows to the cavity between the two grate teeth, the air expands, resulting in turbulent flow, which causes the energy loss of the air flow, and the pressure and speed of the air flow will decrease. decline. In this way, after passing through several grate teeth, the pressure difference before and after the grate teeth is reduced, and the air flow through the gap of the grate teeth is also reduced, thereby reducing the overall leakage.

However, in the practical application of the bearing cavity, the effect of the grate sealing structure in the prior art is not ideal. Especially when the aircraft engine is in a low state, the following problems are usually caused:

1. Since the pressure inside the bearing cavity is higher than the pressure in the surrounding cavity, the gas or lubricating oil in the bearing cavity will leak, which will affect the gas temperature between the bearing cavity and other external chambers, increase the bleed air load, and affect the aircraft engine performance.

2. The operation of the aero-engine needs to ensure bearing lubrication. There is a lubricating oil flow path inside the bearing cavity to maintain circulation. Since the oil temperature will rise after running in the bearing cavity for a period of time, it needs to be led to the external engine through the circulating flow path. The box is cooled to ensure that the lubricating oil continues to work at a more suitable temperature. Since the pressure inside the bearing cavity is higher than the pressure in the surrounding cavity, the lubricating oil inside the bearing cavity may leak, affecting the working efficiency of the bearing, and the leakage The lubricating oil will also lead to further safety hazards in aero-engines;

3. During the working process, there is a gap between the bearing cavity rotor and the stator, and the gas excitation force will cause forced vibration of the bearing cavity components. When the frequency of the excitation force is the same as the natural frequency of the component, resonance will occur. cause serious consequences.

4. Due to the small installation space of the aero-engine bearing cavity, during the axial disassembly and assembly process, the rotor and the stator of the sealing structure are prone to rubbing, and the overly complex sealing structure is not only difficult to process, but also gives The disassembly and assembly of the bearing cavity brings additional difficulty and workload.

SUMMARY OF THE INVENTION

Due to the technical problems existing in the practical application of the grate sealing structure of the prior art in the bearing cavity of aero-engine, the purpose of the present invention is to provide a grate sealing structure of the bearing cavity of an aero-engine, which solves the problems existing in the prior art solutions. To solve the above technical problems, optimize the sealing effect of the bearing cavity, reduce the leakage, and improve the performance of the engine.

The technical scheme of the grate sealing structure of the aero-engine bearing cavity provided by the present invention is: a grate sealing structure for the aero-engine bearing cavity, wherein the bearing cavity is arranged between the main shaft and the casing, and the bearing cavity is formed by the inner part of the bearing. The ring, the bearing, the bearing outer ring, the oil scavenger ring and the grate sealing structure are formed. The grate sealing structure is arranged on both sides of the bearing cavity in the axial direction. A sealing stator and a sealing rotor with the same axis and relatively rotating, the sealing stator is sleeved on the outer side of the sealing rotor, the inner side of the sealing stator is provided with a sealing protection layer, and the outer side of the sealing rotor is A plurality of sealing grate teeth are provided, and the surface of the sealing protection layer is provided with at least one groove, and the depth of the groove is smaller than the thickness of the surface of the sealing protection layer.

Preferably, the grooves are arranged on opposite surfaces of the interval formed by two adjacent sealing grate teeth, and the width of the groove is smaller than the interval formed by two adjacent sealing grate teeth.

Preferably, the groove includes a first groove and a second groove, and the first groove and the second groove are respectively disposed at both ends of the grate sealing structure in the axial direction.

Preferably, the grooves are intermittently distributed along the circumferential direction of the surface of the sealing protection layer.

Preferably, the grooves are intermittently distributed along 90 degrees, and the circumferential angle of each section of the grooves is between 50 degrees and 70 degrees.

Preferably, the cross-sectional shape of the groove along the axial direction of the bearing cavity is a semicircle.

Preferably, the cross-sectional shape of the groove along the axial direction of the bearing cavity is rectangular.

Preferably, the sealing protection layer is a honeycomb structure or an easy-to-wear coating.

Preferably, the cross-sectional area of the sealing grate gradually decreases from the root to the top of the sealing grate, and the top width of the sealing grate is close to zero.

In addition, the present invention also provides an aero-engine, the aero-engine includes a compressor, a combustion chamber and a turbine, the compressor and/or the turbine includes a plurality of bearing cavities, wherein the bearing cavities include any of the aforementioned One-piece grate seal structure.

By applying the grate sealing structure of the bearing cavity and the aero-engine proposed by the present invention, the problems existing in the prior art can be solved from the source, and the following advantages are brought about:

First, the grate sealing structure of the aero-engine bearing cavity provided by the present invention can destroy the boundary layer, generate eddy currents, and reduce gas leakage. When the airflow flows through the narrow gaps of the grate teeth, the groove structure can destroy the boundary layer of the airflow on the honeycomb surface, generate eddy currents, and cause energy dissipation, so that each single-stage grate teeth in the grate seal structure can block the airflow. The effect is strengthened, thereby reducing the leakage of gas, ensuring the sealing effect between the two sides of the cavity, and improving the efficiency and performance of the engine;

Second, the grate sealing structure of the bearing cavity of the aero-engine provided by the present invention can accommodate the lubricating oil in the bearing cavity and reduce the leakage of the lubricating oil in the low state. When the engine is working in a low state, the pressure in the bearing cavity is larger than that outside the cavity, and there is a risk of oil leakage through the grate seal. The groove structure can increase the pressure reduction effect of the single-stage grate and improve the sealing effect. Strict effect, thereby reducing the risk of oil leakage;

Third, the grate seal structure of the aero-engine bearing cavity provided by the present invention, the grate seal is used as a special connection method between the rotor part and the stator part. During the working process, there is a gas exciting force, which increases the groove structure. It can increase the capacity of the cavity between the grate teeth, reduce the gas impact force on the sealing position, and help reduce the vibration of the aero-engine during operation;

Fourth, the grate sealing structure of the bearing cavity of the aero-engine provided by the present invention can effectively reduce the axial friction during the installation process and facilitate the installation. Due to the small space of the bearing cavity, the reliability and feasibility of the assembly and disassembly process can also be ensured while improving the sealing efficiency;

Fifth, the grate sealing structure of the aero-engine bearing cavity provided by the present invention has a simple structure, can be applied to various sealing surfaces such as honeycomb structures and easy-to-wear coatings, and is easy to process. Form processability is better.

These and other objects and advantages will become more apparent to those skilled in the art upon reading the following portions of this specification in conjunction with the accompanying drawings.

Description of drawings

The above summary of the present invention and the following detailed description will be better understood when read in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are merely illustrative of the claimed invention. In the drawings, the same reference numbers represent the same or similar elements.

FIG. 1 is a schematic diagram showing the structure of the bearing cavity of the aero-engine of the present invention.

FIG. 2 is a partially enlarged schematic view of the grate sealing structure of the bearing cavity according to the first preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of a conventional bearing cavity grate sealing structure in the prior art.

FIG. 4 is a schematic diagram of the circumferential structure of the grate sealing structure of the bearing cavity according to the second preferred embodiment of the present invention.

FIG. 5 is a schematic diagram showing the groove structure of the bearing cavity grate sealing structure according to the third preferred embodiment of the present invention.

FIG. 6 is a schematic diagram showing the groove structure of the bearing cavity grate sealing structure according to the fourth preferred embodiment of the present invention.

The reference numbers are as follows:

100. Grate sealing structure

110、Important

111. Seal the protective layer

112. Groove

1121, the first groove

1122, the second groove

120. Seal the rotor

121. Grate Teeth

200, bearing inner ring

300, bearing stator outer ring seat

400, bearing

500, oil scavenger ring

600, spindle

L1, groove width

L2, the interval width formed by two adjacent sealing grate teeth

S1, groove depth

S2, the thickness of the sealing protective layer

α, groove circumferential angle

Detailed ways

The detailed features and advantages of the present invention are described in detail below in the specific embodiment, and the content is sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the description, claims and drawings disclosed in this specification. , those skilled in the art can easily understand the related objects and advantages of the present invention.

Figures 1 to 2 show the technical solution of the grate sealing structure of the aero-engine bearing cavity provided by the present invention. The bearing cavity is provided between the aero-engine main shaft 600 and the casing (not shown in the figure), and the bearing cavity is formed by the inside of the bearing. The ring 200 , the bearing 400 , the bearing stator outer ring seat 300 , the oil scavenger ring 500 and the grate sealing structure 100 are formed, and the grate sealing structure 100 is axially arranged on both sides of the bearing cavity.

Among them, the grate sealing structure 100 has a sealing stator 110 and a sealing rotor 120 that rotate relatively around the same axis, the sealing stator 110 is sleeved on the radial outer side of the sealing rotor 120, and the sealing stator 110 is provided with a sealing The sealing protection layer 111 can be a honeycomb structure or an easy-to-wear coating to prolong the service life of the grate sealing structure. The outer side of the sealing rotor 120 is provided with a plurality of sealing grate teeth 121. The sealing grate teeth gradually decrease in cross-sectional area from the root of the grate teeth to the top, and the top width of the sealing grate teeth is close to zero. The sealing grate structure of the present invention is not limited to the above-mentioned form, and in other embodiments, various traditional grate forms including straight teeth can be used.

The surface of the sealing protection layer 111 is provided with two annular grooves 112, namely the first groove 1121 and the second groove 1122, both of which are arranged on the opposite surfaces of the interval formed by the adjacent two sealing grate teeth, respectively along the It is axially arranged at both ends of the grate sealing structure. The cross-sections of the first groove 1121 and the second groove 1122 are semi-circular, and their widths (diameters) L1 are equal, both smaller than the width L2 of the interval formed by two adjacent sealing grate teeth, and the depth of the groove 112 ( The radius) S1 is smaller than the thickness S2 of the sealing protection layer 111 .

During operation, under the action of the huge pressure difference between the outside and inside of the bearing cavity, the airflow flows along the axial direction of the main shaft 6 of the aero-engine toward the inside of the bearing cavity, while in the low working state, the pressure inside the bearing cavity is larger than that outside the cavity, It is necessary to prevent the airflow from flowing to the outside of the bearing cavity along the axial direction of the main shaft 6 of the aero-engine. By applying the sealing grate structure of the present invention, regardless of the working state, the air flow enters the sealing stator 110 immediately after flowing through the narrow gap between the first-stage grate and the sealing protective layer on both sides of the bearing cavity. The first groove 1121 or the second groove 1122 on the surface of the sealing protective layer on the inner side, through the groove structure, the boundary layer of the air flow on the surface of the sealing protective layer of the sealing structure can be destroyed, and the surface of the sealing protective layer 111 can be generated. The eddy current enhances the degree of energy dissipation of the airflow, so that the blocking effect of the single-stage grate teeth on the airflow is strengthened, thereby reducing the leakage of the gas. The groove structure further increases the volume of the space between the two-stage grate teeth and increases the pressure reduction effect of each stage of the grate teeth, thereby ensuring the sealing effect between the inside and outside of the bearing cavity and improving the efficiency and performance of the engine. .

Secondly, by arranging the groove structure in the sealing protective layer 111, it is possible to allow the inside of the sealing protective layer to accommodate a part of the lubricating oil when the aero-engine is in a low state, because the outward leakage of the lubricating oil in the bearing cavity may cause the aero-engine security risks.

Thirdly, the groove structure in the sealing protection layer 111 can increase the capacity of the cavity formed between the grate teeth, reduce the gas impact force on the sealing position, and help reduce vibration. At the same time, since the groove structure is arranged on the sealing stator 110, the sealing rotor is not changed, so as to avoid the phenomenon of circumferential unevenness on the sealing rotor, resulting in more serious excitation force and rotor imbalance, which can better ensure the rotor state of equilibrium

When disassembling and assembling the bearing cavity, since the sealing stator 110 of the technical solution of the present invention is sleeved on the outer side of the sealing rotor 120, there is no complex matching structure between the sealing stator and the sealing rotor, and it can be disassembled directly in the axial direction. It can effectively avoid the axial rubbing between the sealing stator and the sealing rotor during the process of disassembly and assembly, and no additional tools are required, which greatly reduces the workload of disassembly and assembly.

Fig. 4 shows the second preferred embodiment of the grate seal structure of the aero-engine bearing cavity provided by the present invention, which shows the circumferential distribution of the annular grooves of the grate seal structure, the grate seal The axial structure of the strict structure can be referred to as shown in Figure 2.

The grate sealing structure 100 has a sealing stator 110 and a sealing rotor 120 that rotate relatively around the same axis. The sealing stator 110 is sleeved on the radial outer side of the sealing rotor 120, and the inner side of the sealing stator 110 is provided with sealing protection Layer 111, the sealing protection layer can be a honeycomb structure or an easy-to-wear coating, so as to prolong the service life of the grate sealing structure. The outer side of the sealing rotor 120 is provided with a plurality of sealing grate teeth 121. The sealing grate teeth gradually decrease in cross-sectional area from the root of the grate teeth to the top, and the top width of the sealing grate teeth is close to zero.

The surface of the sealing protection layer 111 is provided with two rings of annular grooves 112, namely the first groove 1121 and the second groove 1122, both of which are arranged on the opposite surfaces of the interval formed by the adjacent two sealing grate teeth, respectively along the It is axially arranged at both ends of the grate sealing structure. The widths L1 of the first groove 1121 and the second groove 1122 are equal, and both are smaller than the width L2 of the interval formed by two adjacent sealing grate teeth, and the depth S1 of the groove 112 is smaller than the thickness S2 of the sealing protection layer 111 .

The first groove 1121 and the second groove 1122 are divided into four sections along the circumferential surface of the sealing protective layer 111 at 90 degrees, and the circumferential angle α of each groove is 60 degrees.

Since the grate 121 rotates with the main shaft 6, there will be a circumferential flow in the rotational direction between the top of the grate and the sealing protective layer 111. When passing through the gap between the top of the grate teeth and the sealing protective layer 111, the groove structure disturbs the regular movement of the airflow in the circumferential direction, so that the airflow expands at each groove, resulting in turbulent flow, which causes the energy loss of the airflow and the pressure of the airflow. And the speed will decrease, part of the energy is dissipated as heat energy, and at the discontinuity of the groove, the airflow speed is further increased, the pressure is reduced, and the leakage of the grate structure is further reduced, improving the sealing effect.

In other embodiments, the circumferential angle α and the circumferential distribution number of each groove can be selected with reference to factors such as the installation position, working conditions and installation space of the grate sealing structure, and the preferred axial angle is 50 degrees to 70 degrees.

5 and 6 show other preferred embodiments of the grate sealing structure of the bearing cavity of an aero-engine provided by the present invention.

As shown in FIG. 5 , in the third embodiment of the grate sealing structure of the aero-engine bearing cavity provided by the present invention, several annular grooves are arranged on the surface of the sealing protection layer, and the number of annular grooves is the number of the sealing grate teeth. The number is reduced by 1, and the annular grooves are arranged on the opposite surface of the interval formed by the adjacent two sealing grate teeth. The width of the interval formed by the grate teeth and the depth (radius) S1 of the groove are smaller than the thickness of the sealing protection layer 111 .

By arranging a plurality of groove structures, the air leakage of the sealing structure is further reduced, and the sealing effect of the whole sealing structure of the grate teeth is improved.

As shown in FIG. 6, the fourth embodiment of the grate sealing structure of the aero-engine bearing cavity provided by the present invention,

A number of annular grooves are arranged on the surface of the sealing protective layer. The number of annular grooves is the number of sealing grate teeth minus 1. The annular grooves are arranged on the opposite surface of the interval formed by two adjacent sealing grate teeth. Its cross section is rectangular, and its axial width L1 is equal, both smaller than the width of the interval formed by two adjacent sealing grate teeth, and the depth S1 of the groove is smaller than the thickness of the sealing protection layer 111 .

By adjusting the cross-sectional shape of the groove structure, in other embodiments, the geometric parameters of the groove can be selected with reference to factors such as the installation position, working conditions and installation space of the grate sealing structure.

The present invention also provides an aero-engine including a compressor, a combustion chamber and a turbine, wherein the bearing cavity of the compressor and the turbine includes the aforementioned grate sealing structure, so as to obtain a stronger sealing effect and safety, and saves the work required for the disassembly and assembly of the bearing housing.

It can be seen from the above embodiments that the application of the bearing cavity grate sealing structure and the aero-engine provided by the present invention can destroy the boundary layer of the airflow passing through the sealing grate, generate eddy currents, reduce gas leakage, and ensure the cavity on both sides. The sealing effect between the grooves can improve the efficiency and performance of the engine; it can accommodate the lubricating oil in the bearing cavity, reduce the leakage of lubricating oil in the low state, and improve the sealing effect; it can increase the groove structure and increase the cavity between the grate teeth. It can reduce the gas impact force on the sealing position, which is conducive to reducing vibration; it has a simple structure, easy to process, and has good processability compared with other existing sealing structure technical solutions; it can effectively reduce the axial direction during the installation process. Scrub, easy to install. Due to the small space of the bearing cavity, the reliability and feasibility of the assembly and disassembly process can also be ensured while the sealing efficiency is improved.

The terms and expressions used herein are for description only, and the present invention should not be limited to these terms and expressions. The use of these terms and expressions is not intended to exclude any equivalents of those shown and described (or portions thereof), and it should be recognized that various modifications that may exist should also be included within the scope of the claims. Other modifications, changes and substitutions may also exist. Accordingly, the claims should be deemed to cover all such equivalents.

Also, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, those skilled in the art should realize that the above embodiments are only used to illustrate the present invention, without departing from the present invention. Various equivalent changes or substitutions can also be made under the spirit of the present invention. Therefore, as long as the changes and modifications to the above-mentioned embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of the present application.

Claims (10)

1. A grate sealing structure for an aero-engine bearing cavity, the bearing cavity is arranged between the main shaft and the casing of the aero-engine, and the grate sealing structure is axially arranged on the bearing both sides of the cavity to seal the bearing cavity, It is characterized in that: the grate sealing structure has a sealing stator and a sealing rotor that rotate relatively around the same axis, the sealing stator is sleeved on the radial outer side of the sealing rotor, and the sealing stator is The inner side of the rotor is provided with a sealing protection layer, the outer side of the sealing rotor is provided with a number of sealing grate teeth, and the surface of the sealing protection layer is at a distance corresponding to the interval formed by two adjacent sealing grate teeth. At least one position is provided with a groove, and the depth of the groove is smaller than the thickness of the sealing protection layer. 2 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the width of the groove is smaller than the interval formed by two adjacent sealing grate teeth. 3 . 3. The grate sealing structure for aero-engine bearing cavity according to claim 2, wherein the groove comprises a first groove and a second groove, the first groove and the The second grooves are respectively arranged at both ends of the grate sealing structure along the axial direction. 4 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the grooves are distributed intermittently and/or continuously along the circumference of the surface of the sealing protection layer. 5 . 5. The grate sealing structure for aero-engine bearing chambers according to claim 4, wherein the grooves are intermittently distributed into four sections along 90 degrees, and the circumferential angle of each section of the grooves is Between 50 and 70 degrees. 6 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the cross-sectional shape of the groove along the axial direction of the bearing cavity is a semicircle. 7 . 7 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the cross-sectional shape of the groove along the axial direction of the bearing cavity is a rectangle. 8 . 8 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the sealing protective layer is a honeycomb structure or an easy-to-wear coating. 9 . 9 . The grate sealing structure for aero-engine bearing cavity according to claim 1 , wherein the sealing grate has a gradually decreasing cross-sectional area from the root to the top of the sealing grate, and The top width is close to 0. 10. An aero-engine comprising a compressor, a combustion chamber and a turbine, the compressor and/or the turbine comprising a plurality of bearing cavities, characterized in that at least one of the bearing cavities has a bearing cavity as claimed in claim 1 . The grate sealing structure described in any one of -9.

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