A labyrinth seal and a seal

Abstract

Provided is a labyrinth sealing structure, comprising an airflow channel and a plurality of pre-swirl vanes, a gas collection port of the airflow channel is arranged on an axial outer sidewall of a circumferential labyrinth ring facing a first space and / or a second space, and an outlet is arranged on an outer peripheral surface of the circumferential labyrinth ring; the plurality of pre-swirl vanes are arranged on a circumferential side of the circumferential labyrinth ring, and the outlet is located between adjacent pre-swirl vanes; wherein the airflow channel is used to introduce a tooth bottom airflow in the first space or / and the second space, and to guide the tooth bottom airflow to be discharged through the outlet after ascending radially to form a tooth top airflow; and the pre-swirl vanes are used to supercharge the tooth top airflow and to guide the tooth top airflow to change direction, so that the tooth top airflow is sprayed towards a first airflow flow direction to block the first airflow. The structure has a better sealing effect. Also provided is a sealing structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aero-engine sealing, in particular to the field of bearing cavity sealing between engine rotor and stator. BACKGROUND

[0002] With the development of aviation industry, the requirements for the maneuverability, reliability and economy of the aircraft are getting higher and higher, so it is urgent to improve the components of the aero-engine to ensure the high performance requirements of the engine. Low fuel consumption, high thrust-to-weight ratio, reliability and durability are the development trend of modern aero-gas turbine engines, but the internal temperature and pressure ratio of the engine are gradually increasing, which makes the leakage of the internal flow coefficient more and more serious, and the performance of the sealing directly affects the working performance of the aero-engine such as fuel performance consumption rate, flight cost and thrust-to-weight ratio. In order to reduce the leakage loss and improve the overall performance of the engine, it is particularly important to improve the original sealing device at many positions.

[0003] Researches at home and abroad show that half of the performance improvement of future aero-engines will depend on the improvement of sealing technology and the reduction of leakage. Therefore, the demand for high-performance sealing structure is becoming more and more urgent, and the improvement and development of new sealing device have important practical value for reducing fuel consumption and improving engine efficiency.

[0004] In order to ensure the sealing of the gas path between the rotor and the stator, the most widely used sealing structure in the active engine is the sealing gill structure, which is a non-contact dynamic sealing that increases the flow resistance by sudden expansion and sudden contraction of the channel to limit the fluid leakage. The main function of the bearing cavity lubricating oil seal is to effectively isolate the bearing cavity of the rotor system of the engine from the airflow environment of the engine, protect the bearing and lubricating oil from the airflow flow path, and prevent the leakage of lubricating oil. Therefore, in order to avoid the occurrence of reverse pressure difference at the sealing place and the leakage of lubricating oil from the sealing through-flow gap, the air pressure outside the bearing cavity is increased, but this will also lead to the increase of air leakage and the increase of lubricating oil consumption, and even the leakage of high-temperature and high-pressure gas into the bearing cavity will increase the risk of burning and coking of lubricating oil in the bearing cavity.

[0005] Therefore, it is necessary to provide a gill sealing structure to further improve the sealing performance. SUMMARY

[0006] An object of the present application is to provide a gill sealing structure which can strengthen the sealing effect of the tooth top and effectively block the leakage of gas.

[0007] To achieve the above-mentioned purpose, the labyrinth sealing structure is arranged on the rotor member, and is used for blocking the flow of the first airflow between the first space and the second space. The labyrinth sealing structure comprises a plurality of circumferential labyrinth rings, a gas flow channel and a plurality of pre-swirl vanes. The gas inlet of the gas flow channel is arranged on the axial outer wall of the circumferential labyrinth ring facing the first space and / or the second space, and the outlet is arranged on the outer circumferential surface of the circumferential labyrinth ring. The plurality of pre-swirl vanes are arranged on the circumferential side of the circumferential labyrinth ring, and the outlet is located between adjacent pre-swirl vanes. The gas flow channel is used for introducing the tooth bottom airflow in the first space and / or the second space, and guiding the tooth bottom airflow to rise radially and then be discharged through the outlet to form a tooth top airflow. The pre-swirl vanes are used for pressurizing the tooth top airflow and guiding the tooth top airflow to change direction, so that the tooth top airflow is sprayed towards the flow direction of the first airflow to block the first airflow.

[0008] In one or more embodiments, the structure further comprises a plurality of pressurizing plates arranged around each gas inlet to form a gas collecting lug. The pressurizing plate has a certain curvature, so that the gas collecting lug forms an arc-shaped flow channel for sucking the tooth bottom airflow.

[0009] In one or more embodiments, the curvature of the pressurizing plate is arranged in the same direction as the rotation direction.

[0010] In one or more embodiments, the circumferential side of the circumferential labyrinth ring comprises an annular gas collecting cavity, and the pre-swirl vanes are arranged in the annular gas collecting cavity. Adjacent pre-swirl vanes and the annular gas collecting cavity jointly define a flow space of the tooth top airflow.

[0011] In one or more embodiments, the gas flow channel is tapered in the radial direction.

[0012] Another purpose of the present application is to provide a sealing structure comprising a rotor member and a stator member. The rotor member comprises the above-mentioned labyrinth sealing structure.

[0013] In one or more embodiments, the stator member comprises a sealing ring, and the sealing ring forms a gap with the circumferential labyrinth ring.

[0014] In one or more embodiments, the inner circumferential surface of the sealing ring is a honeycomb structure or a coating structure.

[0015] The above-mentioned labyrinth sealing structure can effectively block the flow of the first airflow by setting the airflow passage to suck the airflow at the tooth bottom, and by setting the pre-rotation blade on the circumferential labyrinth ring to compress the airflow at the tooth bottom to increase the pressure and change the direction to form the airflow at the tooth top, which is sprayed towards the flow direction of the first airflow, and the two airflow streams impacting each other can form a turbulent flow at the tooth top, further blocking the flow of the subsequent first airflow, thereby effectively blocking the airflow flow between the first space and the second space, and the airflow compressed by the pre-rotation blade forms a high-pressure area at the tooth top, thereby blocking the airflow flow on both sides of the labyrinth, thereby forming a better sealing effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other features, properties, and advantages of the present application will become more apparent by referring to the following description in conjunction with the accompanying drawings, in which:

[0017] Figure 1 is a schematic diagram of an aero-engine bearing cavity.

[0018] Figure 2 is a three-dimensional cutaway schematic diagram of an embodiment of a sealing labyrinth.

[0019] Figure 3 is a sectional view of an embodiment of a sealing labyrinth.

[0020] Figure 4 is a sectional view along the direction of A-A in Figure 3 .

[0021] SYMBOL EXPLANATION

[0022] 1, bearing cavity

[0023] 2, conventional sealing structure

[0024] 3, first bearing

[0025] 4, second bearing

[0026] 5, rotor member

[0027] 6, stator member

[0028] 10, bearing outer cavity

[0029] 11, bearing inner cavity

[0030] 12, compressed gas

[0031] 13, oil-gas airflow

[0032] 15, first airflow

[0033] 30, gas collection port

[0034] 31, airflow passage

[0035] 32. pre-swirl vane

[0036] 33. annular plenum

[0037] 36. outlet

[0038] 37. plenum plate

[0039] 50. circumferential labyrinth ring

[0040] 51. first circumferential labyrinth ring

[0041] 52. second circumferential labyrinth ring

[0042] 53. third circumferential labyrinth ring

[0043] 60. direction of rotation

[0044] 61. seal ring

[0045] 73. tooth bottom airflow

[0046] 74. tooth top airflow

[0047] 100. first space

[0048] 200. second space DETAILED DESCRIPTION

[0049] The present application is further described in connection with the following specific embodiments and the accompanying drawings, in which more details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, that the present application can be practiced in a variety of ways without departing from the spirit and scope of the present application as set forth in the claims. Reference will now be made in detail to specific embodiments of the application.

[0050] It is to be understood that these and other drawings, which follow, are merely examples and are therefore to be regarded as being illustrative rather than a limitation on the scope of the application as set forth in the claims.

[0051] Referring to Figure 1 illustrated, the bearing cavity 1 formed between the rotating and stationary stators in an aeroengine is typically sealed using air and a conventional seal 2 to ensure that the oil used to lubricate and cool the first 3 and second 4 bearings does not leak.

[0052] During the operation of the engine, the oil in the bearing inner cavity 11 usually exists in the form of oil gas, the bearing outer cavity 10 will introduce a certain pressure compressed gas 12 into the bearing inner cavity 11, the compressed gas 12 tries to block the oil gas flow 13 from leaking into the bearing inner cavity 11, so as to establish the pressure of the bearing inner cavity 11. In order to improve the sealing effect of the compressed gas 12 on the oil gas flow 13, or even reduce the amount of the compressed gas 12, a labyrinth sealing structure is usually designed between the rotor 5 and the stator 6.

[0053] Figures 2 to 4 The labyrinth sealing structure disclosed in the present application can avoid the flow between air and oil gas, and improve the sealing effect.

[0054] It should be noted that the following description uses the words “first”, “second”, etc. to limit the parts, which is only for the convenience of distinguishing the corresponding parts. If there is no further declaration, the above words do not have special meanings, and do not mean primary and secondary, so it cannot be understood as a limitation on the protection scope of the present application.

[0055] Figure 2 The labyrinth sealing structure shown is arranged on the rotor 5, and is used to block the flow of the first gas flow 15 between the first space 100 and the second space 200. The first space 100 and the second space 200 can be Figure 1 The bearing outer cavity 10 referred to in the middle will introduce the compressed gas 12 into the bearing inner cavity 11, or other two cavities that need to be sealed.

[0056] The first gas flow 15 can be the compressed gas 12 introduced from the bearing outer cavity 10 into the bearing inner cavity 11, or the oil gas flow 13 leaked from the bearing inner cavity 11 into the bearing outer cavity 10.

[0057] The labyrinth sealing structure is used to block the exchange between the gas flows between the bearing outer cavity 10 and the bearing inner cavity 11, avoid the compressed gas 12 entering the bearing inner cavity 11 to cause large oil consumption and combustion coking risk, and also used to block the oil gas flow 13 from leaking into the bearing outer cavity 10, so as to avoid the influence of the oil gas on the gas flow environment of the engine.

[0058] The labyrinth sealing structure includes a plurality of circumferential labyrinth rings 50, and also includes a gas flow passage 31 and a plurality of pre-swirl vanes 32. The gas collecting port 30 of the gas flow passage 31 is arranged on the axial outer side wall of the circumferential labyrinth ring 50 facing the first space 100 and / or the second space 200, and the outlet 36 is arranged on the outer peripheral surface of the circumferential labyrinth ring 50. The plurality of pre-swirl vanes 32 are arranged on the circumferential side of the circumferential labyrinth ring 50, and the outlet 36 is located between adjacent pre-swirl vanes 32.

[0059] The airflow passage 31 is used to introduce the tooth bottom airflow 73 in the first space 100 or / and the second space 200, and direct the tooth bottom airflow 73 to rise radially and then be discharged through the outlet 36 to form the tooth top airflow 74. The pre-rotation vane 32 is used to increase the pressure of the tooth top airflow 74, and direct the tooth top airflow 74 to change direction so as to be sprayed towards the flow direction of the first airflow 15 to block the first airflow 15.

[0060] Figure 2 And Figure 3 The embodiment shown in

[0061] Continuing to refer to Figure 3 And 4 There is a tooth bottom airflow 73 near the first circumferential labyrinth 51 in the first space 100 or / and the second space 200, which is sucked into the airflow passage 31 by the gas collecting port 30.

[0062] Since the airflow passage 31 extends radially, the tooth bottom airflow 73 can rise radially in the tooth height direction and be finally discharged through the outlet 36 on the circumferential side of the first circumferential labyrinth 51. At this time, the tooth bottom airflow 73 has become the tooth top airflow 74.

[0063] The tooth top airflow 74 is compressed by the pre-rotation vane 32 and then sprayed from the tooth tip with a certain pre-rotation angle to block the axial flow of the first airflow 15. The impinging tooth top airflow 74 and the first airflow 15 form a turbulent flow at the tooth top, which further blocks the flow of the subsequent first airflow, thereby effectively blocking the airflow between the first space 100 and the second space 200 and forming a better sealing effect.

[0064] Meanwhile, the pre-rotation vane 32 compresses the tooth top airflow 74 to increase the pressure of the tooth top airflow 74, so that the pressure at the tooth top is higher than that on both sides, which further blocks the flow of the airflow on both sides.

[0065] In order to further obtain a better air suction effect, in an embodiment, the structure further comprises a plurality of booster plates 37 arranged around each gas collecting port 30 to form a gas collecting lug. The booster plate 37 has a certain curvature to form an arc-shaped flow channel for sucking the tooth bottom airflow 73.

[0066] In combination with Figure 2As shown, the arc of the booster plate 37 is arranged in the same direction as the rotation direction 60, and defines an arc-shaped flow channel. This structure can disturb the air flow distribution near the tooth bottom during rotation, increase the pressure on the arc surface side, and increase the suction effect of the air flow near the tooth bottom during rotation.

[0067] To obtain better sealing effect, the tooth tip air flow 74 at the outlet is carefully designed to form a strong air flow that effectively counteracts the first air flow 15 by means of the interference of the engine rotating shaft and the pre-rotation blade 32.

[0068] In an embodiment, the circumferential side of the circumferential gill ring 50 comprises an annular gas collecting cavity 33, and the pre-rotation blade 32 is arranged in the annular gas collecting cavity 33. Adjacent pre-rotation blades 32 and annular gas collecting cavities 33 jointly define the flow space of the tooth tip air flow 74.

[0069] In combination Figure 4 As shown, the annular gas collecting cavity 33 is located on the circumferential side of the circumferential gill ring 50, and the pre-rotation blade 32 is arranged in the annular gas collecting cavity 33. Preferably, the height of the pre-rotation blade 32 is the same as the depth of the annular gas collecting cavity 33.

[0070] The outlet 36 of the air flow channel 31 is arranged between the pre-rotation blades 32, and the flow space of the tooth tip air flow 74 is defined by the two adjacent pre-rotation blades 32 and the two side walls of the annular gas collecting cavity 33. The tooth tip air flow 74 is compressed and boosted in pressure at the flow space, and the flow direction is changed.

[0071] Specifically, the pre-rotation blade 32 is designed to change the direction of the tooth tip air flow 74, so that the tooth tip air flow 74 flows out along the circumferential tangent direction of the blade. For example, the tooth tip air flow 74 is discharged through the outlet 36 in the direction shown by V1. Under the action of the tangential velocity Vr of the engine rotating shaft, the original V1 velocity becomes V2. At this time, the tooth tip air flow 74 sprayed by the gill tooth tip is a high-speed air flow with V2 direction. This high-speed air flow will effectively block the flow of the axial first air flow 15, and form a turbulent flow near the tooth tip.

[0072] And affected by the tooth tip air flow 74, the pressure at the tooth tip will also be greater than the pressure on both sides of the first circumferential gill ring 51, forming a high-pressure area. The high-pressure area will further resist the mutual flow of the air flows on both sides, and in addition, the gas at the high-pressure area will naturally flow to the low-pressure areas on both sides, thereby forming an air flow opposite to the flow direction of the first air flow 15, further playing a sealing role.

[0073] In an embodiment, the air flow channel 31 is tapered in the radial direction, to further increase the flow rate of the tooth tip air flow discharged.

[0074] Therefore, the above-mentioned labyrinth sealing structure can effectively seal the airflow flow between the first space and the second space at each rotating speed stage, thereby reducing the demand for the bleed air quantity of the compressor, and the reduced bleed air quantity of the compressor can improve the overall performance of the engine, reduce the fuel consumption of the engine, increase the flight range of the aircraft under the same oil load, and reduce the turbine inlet temperature, thereby prolonging the service life of the turbine, prolonging the overhaul and scrap cycle of the engine, effectively reducing the cost, and reducing the bearing cavity lubricating oil consumption and blocking the high-temperature sealing gas and the oil gas in the oil cavity, thereby effectively improving the working performance of the bearing, ensuring effective lubrication and cooling. At the same time, blocking the high-temperature sealing gas and the oil gas in the oil cavity can prevent the high-temperature and high-pressure gas from leaking into the bearing cavity and causing the lubricating oil to burn and coke in the bearing cavity.

[0075] In combination with the above description of the labyrinth sealing structure, it can be understood that a sealing structure includes the stator 6 and the rotor 5, and the above-mentioned labyrinth sealing structure is used on the rotor 5.

[0076] The sealing ring 61 is arranged on the stator 6, and a gap is formed between the sealing ring 61 and the circumferential labyrinth ring 50. A gap exists between the tooth top of the labyrinth and the inner ring of the sealing ring 61, which can prevent the rotor and the stator from colliding and grinding, and can reduce the circulation of air in and out of the bearing cavity 1, thereby achieving the sealing effect.

[0077] In an embodiment, the inner circumferential surface of the sealing ring 61 is a honeycomb structure or a coating structure to enhance the sealing effect.

[0078] The above-mentioned sealing structure has a good sealing effect, which can effectively prevent the airflow in the first space and the second space from flowing into each other, reduce the fuel consumption of the engine, and improve the overall performance of the engine.

[0079] At the same time, specific words are used in the present application to describe the embodiments of the present application. As "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "one embodiment" or "one alternative embodiment" mentioned in different places in the specification does not necessarily mean the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0080] Similarly, it should be noted that, in order to simplify the description of the present application and to help understand one or more embodiments of the present application, sometimes multiple features are combined into one embodiment, figure or description thereof. However, this method of disclosure does not mean that the features required by the present application are more than those mentioned in the claims. In fact, the features of the embodiment are less than all the features of the above-mentioned single embodiment.

[0081] Although the present application is disclosed with reference to the preferred embodiments above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solutions of the present application, all fall within the protection scope defined by the claims of the present application.

Claims

1. A toothed sealing structure, disposed on a rotor component (5), for blocking the flow of a first airflow (15) between a first space (100) and a second space (200), comprising multiple rows of circumferential toothed rings (50), characterized in that, Also includes: An airflow channel (31) is provided with an air collection port (30) on the axial outer side wall of the circumferential toothed ring (50) facing the first space (100) and / or the second space (200), and an outlet (36) is provided on the outer circumferential surface of the circumferential toothed ring (50). Multiple pre-rotating blades (32) are disposed on the circumferential side of the circumferential toothed ring (50), and the outlet (36) is located between adjacent pre-rotating blades (32); The airflow channel (31) is used to introduce the tooth bottom airflow (73) in the first space (100) and / or the second space (200), and guide the tooth bottom airflow (73) to rise radially and then be discharged through the outlet (36) to form the tooth top airflow (74). The pre-rotating blade (32) is used to pressurize the tooth top airflow (74) and guide the tooth top airflow (74) to change direction, so that the tooth top airflow (74) is ejected in the direction of the flow of the first airflow (15) to block the first airflow (15).

2. The toothed sealing structure as described in claim 1, characterized in that, The structure also includes multiple pressure plates (37), which are respectively arranged around each of the air collection ports (30) to form air collection lugs. The pressure plates (37) have a certain curvature so that the air collection lugs form an arc-shaped flow channel for drawing the airflow (73) from the bottom of the tooth.

3. The toothed sealing structure as described in claim 2, characterized in that, The arc direction of the pressure plate (37) is set to be the same as the rotation direction.

4. The toothed sealing structure as described in claim 1, characterized in that, The circumferential side of the circumferential toothed ring (50) includes an annular air collection chamber (33), and the pre-rotating blade (32) is disposed in the annular air collection chamber (33). The adjacent pre-rotating blade (32) and the annular air collection chamber (33) together define the flow space of the airflow (74) at the tooth tip.

5. The toothed sealing structure as described in claim 1, characterized in that, The airflow channel (31) is gradually narrowed in the radial direction.

6. A sealing structure, comprising a stator and a rotor, characterized in that, The rotor component (5) includes a toothed sealing structure as described in any one of claims 1-5.

7. The sealing structure as described in claim 6, characterized in that, The stationary component (6) includes a sealing ring (61), which forms a gap with the circumferential toothed ring (50).

8. The sealing structure as described in claim 7, characterized in that, The inner circumferential surface of the sealing ring (61) is a honeycomb structure or a coating structure.

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