Grate tooth brush type composite sealing device with self-adaptability and high sealing performance and mounting method

Abstract

The invention discloses a labyrinth brush type composite sealing device with self-adaptability and high sealing performance and an installation method. The labyrinth brush type composite sealing device comprises a labyrinth disc, and a tooth cavity is formed between every two adjacent labyrinth teeth on the labyrinth disc; a plurality of sealing cavities are formed in an inner ring of the mounting seat, the inner ring of the mounting seat is opposite to one side of the labyrinth on the labyrinth disc, and the sealing cavities correspond to the labyrinth in a one-to-one mode; mounting grooves are formed in the mounting seat between every two adjacent sealing cavities, the multiple mounting grooves correspond to the multiple tooth cavities in a one-to-one mode, metal sealing rings are arranged in the mounting grooves, and brush rings are arranged between the tooth cavities and the metal sealing rings; the airflow dissipation and friction effects are enhanced, the ventilation effect is weakened, and the overall sealing performance of the structure is improved.

Description

Technical Field

[0001] The present invention relates to the field of gas sealing in aero-engines and gas turbines, and in particular to a labyrinth brush composite sealing device with self-adaptability and high sealing performance and an installation method thereof. Background Art

[0002] When an aero-engine and a gas turbine are operating, due to the influence of factors such as centrifugal force, deformation caused by temperature change, lack of concentricity, aerodynamic load, and vibration on the rotor component, sufficient clearance must be left between the rotor and the stator to avoid rubbing or damage between the rotor and the stator. The existence of the clearance will inevitably lead to gas leakage, resulting in a reduction in the working performance of the aero-engine and the gas turbine. Research shows that when the leakage of the unit is reduced by 1%, the thrust of a general aero-engine will increase by 1%, the energy consumption rate will decrease by 0.1%, the thrust of an advanced aero-engine will increase by 0.8%, and the energy consumption rate will decrease by 0.5%. It can be seen that the sealing device has a crucial impact on the engine performance.

[0003] The commonly used sealing devices in engines can be divided into contact seals and non-contact seals according to whether the rotor and the stator are in contact. The former mainly includes piston rings, leather cups, floating rings, graphite, finger seals, and brush seals, etc., and the latter mainly includes labyrinth, spiral groove, gas film, and hydrodynamic seals, etc.

[0004] Among them, the labyrinth seal has the advantages of simple structure and easy maintenance, so its application in engines is very extensive. However, its insufficient sealing performance and the inability to tolerate rubbing between the rotor and the stator limit its application in advanced aero-engines.

[0005] The leakage of the brush seal is only 10% - 20% of that of the labyrinth seal. The special structure of the brush bundle can well cope with the problems of rotor radial runout and deformation caused by centrifugal force and temperature. Its disadvantages are that there are problems such as brush wire wear and heat generation due to friction. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a labyrinth brush composite sealing device with self-adaptability and high sealing performance and an installation method thereof.

[0007] The present invention is achieved through the following technical solutions.

[0008] A labyrinth brush composite sealing device with self-adaptability and high sealing performance provided by the present invention includes a labyrinth disc, and tooth cavities are formed between two adjacent labyrinth teeth on the labyrinth disc;

[0009] It further includes a mounting seat, and a plurality of sealing cavities are arranged inside the mounting seat in a ring shape. The inner ring of the mounting seat is arranged opposite to one side of the labyrinth teeth on the labyrinth disc, and the plurality of sealing cavities respectively correspond to the plurality of labyrinth teeth one by one;

[0010] The mounting base is provided with mounting grooves between adjacent two sealing cavities, and the multiple mounting grooves correspond to the multiple tooth cavities one by one. A metal sealing ring is arranged in each mounting groove, and a brush ring is arranged between the tooth cavity and the metal sealing ring.

[0011] Preferably, the metal sealing ring is arranged in a W shape, an O shape, a C shape or an Ω shape.

[0012] Preferably, a honeycomb ring is arranged in the sealing cavity, and there is a clearance fit between the honeycomb ring and the top of the labyrinth teeth.

[0013] Preferably, the mounting base, the metal sealing ring and the brush ring are all composed of four equal arc segments.

[0014] Preferably, the multiple labyrinth teeth and the multiple brush rings are arranged in an alternating manner in sequence.

[0015] Preferably, a wear-resistant coating is arranged on the inner wall of the tooth cavity.

[0016] Preferably, the number of labyrinth teeth on the labyrinth disc is 4.

[0017] Preferably, the brush ring is composed of a brush bundle, a front baffle and a rear baffle. The front baffle and the rear baffle are respectively fixedly arranged on both sides of the brush bundle. The width of the front baffle is smaller than that of the rear baffle, and the width of the rear baffle is smaller than that of the brush bundle.

[0018] On the other hand, the present invention also provides an installation method for a labyrinth brush type composite sealing device with self - adaptability and high sealing performance, including the following steps:

[0019] S1: Connect the labyrinth disc with the rotating part, and then jointly mount the labyrinth disc and the rotating part on the engine rotating shaft.

[0020] S2: First, respectively install each arc segment in each metal sealing ring into the corresponding mounting groove, and then respectively install each arc segment in each brush ring into the corresponding mounting groove, so that the brush ring and the metal sealing ring in the same mounting groove are in contact, and at this time, the metal sealing ring is not extruded by external force.

[0021] S3: Then, respectively fix each arc segment in each honeycomb ring on the inner wall surface of the corresponding sealing cavity by brazing, so that there is a clearance fit between the opposite labyrinth tooth tops and the honeycomb ring.

[0022] S4: Connect any two arc segments on each mounting base through the ear blocks of the bolt - connected outer ring to form a semi - circular arc - shaped mounting base.

[0023] S5: Jointly assemble the semi - circular arc - shaped mounting bases on the inner casing of the flow passage. The inner ring of the mounting base is oppositely installed with the labyrinth teeth side of the labyrinth disc, so that the end of the brush ring far away from the mounting groove is in contact with the bottom of the tooth cavity.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. Insert a brush ring between the labyrinth disc tooth cavity and the mounting seat, which enhances the air flow dissipation and friction effect, weakens the ventilation effect, and improves the overall sealing performance of the structure.

[0026] 2. When the labyrinth disc undergoes radial morphological changes due to factors such as centrifugal force, temperature, and working conditions, the brush ring and the metal sealing ring can be compressed and extended radially in the mounting groove, reducing the heat generation and wear caused by the friction of the brush filaments, improving the service life of the brush ring. The metal sealing ring ensures that the free ends of the brush bundles are always in contact with the tooth cavity wall surface in various forms of the labyrinth disc, guaranteeing the sealing performance.

[0027] 3. By setting the metal sealing ring in the shape of W, O, C, or Ω, the metal sealing ring has a certain deformation ability and a certain buffering effect, and thus has an adaptive ability to the radial runout and deformation of the labyrinth disc.

[0028] 4. Due to the presence of the honeycomb ring, when designing the tip clearance of the labyrinth seal, the tip clearance can be further reduced. While ensuring the sealing performance of the composite sealing device, the problem of damage to the labyrinth caused by rubbing is effectively reduced. Description of the Drawings

[0029] Figure 1 is the structural schematic diagram of the present invention;

[0030] Figure 2 is the specific structural schematic diagram of the present invention;

[0031] Figure 3 is the enlarged schematic diagram of part A in the present invention;

[0032] Figure 4 is the sealing principle diagram of the labyrinth seal in the present invention;

[0033] Figure 5 is the partial assembly structural schematic diagram of the present invention;

[0034] Figure 6 is the partial assembly structural schematic diagram of the present invention mainly used to show the labyrinth disc and the mounting seat;

[0035] Figure 7 is the structural schematic diagram of the present invention mainly used to show the brush ring;

[0036] In the figure: 1 - outer casing of the flow channel; 2 - inner casing of the flow channel; 3 - rotating part; 4 - labyrinth brush type composite device; 41 - mounting seat; 42 - honeycomb ring; 43 - metal sealing ring; 44 - brush ring; 4401 - brush bundle; 4402 - front baffle; 4403 - rear baffle; 45 - labyrinth disc; 46 - sealing cavity; 47 - mounting groove; 48 - labyrinth teeth; 49 - tooth cavity; 410 - wear-resistant coating. Detailed implementation mode

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0039] Embodiment 1

[0040] Referring to Figure 1 , in the mainstream passage area of the gas turbine engine, a flow passage outer casing 1, a flow passage inner casing 2 and a rotating member 3 are installed. The engine rotating shaft passes through the mainstream passage area of the gas turbine engine, and the rotating member 3 is fixedly installed on the engine rotating shaft. Among them, the flow passage outer casing 1 and the flow passage inner casing 2 are stationary members, and the labyrinth brush composite device 4 is jointly installed on the engine rotating shaft and the flow passage inner casing 2 to achieve the seal between the engine rotating shaft and the stationary member.

[0041] In this embodiment, referring to Figure 2 and Figure 4 , the labyrinth brush composite device 4 includes a labyrinth disk 45. The labyrinth disk 45 is connected to the rotating member 3, and at the same time, the labyrinth disk 45 and the rotating member 3 are jointly installed on the engine rotating shaft. Between two adjacent labyrinths 48 on the labyrinth disk 45, a tooth cavity 49 is formed. The inner bottom surface of the tooth cavity 49 is set as a concave arc surface, which reduces the pressure difference of the air flow to a certain extent;

[0042] It also includes a mounting seat 41. The outer side of the mounting seat 41 is fixedly installed on the flow passage inner casing 2. A plurality of sealing cavities 46 are arranged inside the mounting seat 41 in a ring shape. The sealing cavities 46 and the labyrinths 48 are arranged opposite to each other, and the plurality of sealing cavities 46 respectively correspond to the plurality of labyrinths 48 one by one; A honeycomb ring 42 is arranged in the sealing cavity 46. The honeycomb ring 42 and the top of the labyrinth 48 are in clearance fit, so that a labyrinth seal is formed between the wall surfaces of the labyrinth 48 and the honeycomb ring 42, further reducing the gap between the top of the labyrinth 48 and the sealing cavity 46, which helps to strengthen the sealing performance of the labyrinth seal, and can also protect the labyrinth 48, and as much as possible avoid damage to the labyrinth 48 during the mutual rubbing process, and strengthen the stability of the structure.

[0043] Referring to Figure 1 , Figure 5 and Figure 6, the mounting base 41 is equally divided into four arc segments, and at the same time each honeycomb ring 42 is also equally divided into four arc segments, which are respectively fixed in the sealing cavity 46 by brazing, facilitating the installation of the mounting base 41 onto the labyrinth disc 45 and facilitating assembly and disassembly.

[0044] In this embodiment, referring to Figure 2 and Figure 3 , the mounting base 41 is provided with mounting grooves 47 between two adjacent sealing cavities 46. The multiple mounting grooves 47 correspond to the multiple tooth cavities 49 one by one. A metal sealing ring 43 is arranged in the mounting groove 47. The metal sealing ring 43 is arranged in a W shape, so that the metal sealing ring 43 has a certain deformation force. A brush ring 44 is arranged between the tooth cavity 49 and the metal sealing ring 43. One end of the brush ring 44 is inserted into the mounting groove 47 and contacts the metal sealing ring 43, and the other end abuts against the bottom of the tooth cavity 49, so that the brush ring 44 has an interference fit with the inner wall of the tooth cavity 49. The inner wall of the tooth cavity 49 is provided with a wear-resistant coating 410, which helps to reduce the wear of the brush ring 44 placed in the tooth cavity 49.

[0045] In this embodiment, referring to Figure 2 , Figure 3 and Figure 7 , the brush ring 44 can be made of non-metallic brush wire materials, such as aramid fiber wires, quartz glass fiber wires, carbon fiber wires. The brush ring 44 can also be made of metal brush wires, such as cobalt alloy and nickel alloy; the brush ring 44 is composed of a brush bundle 4401, a front baffle 4402 and a rear baffle 4403. The front baffle 4402 and the rear baffle 4403 are respectively fixedly arranged on both sides of the brush bundle 4401. The width of the front baffle 4402 is smaller than the width of the rear baffle 4403, and the width of the rear baffle 4403 is smaller than the width of the brush bundle 4401, which are all convenient for enhancing the sealing performance of the brush ring 44 between the labyrinth disc 45 and the mounting base 41.

[0046] In this embodiment, a brush seal is formed among the metal sealing ring 43, the brush ring 44 and the tooth cavity 49, which increases the turbulence of the air flow in the tooth cavity 49, enhances the friction effect and the tooth cavity dissipation effect. At the same time, the high-speed jet passing through the tip clearance of the labyrinth teeth 48 is directly blocked by the brush ring 44, thereby weakening the air permeability effect of the labyrinth seal, and the sealing performance of the whole structure is greatly improved.

[0047] In this embodiment, the metal sealing ring 43 and the brush ring 44 are both equally divided into four arc segments, and are respectively and sequentially installed on the mounting base 41 of each arc segment, which is convenient for installing the whole metal sealing ring 43 and the whole brush ring 44 onto the mounting base 41. By setting the metal sealing ring 43 in a W shape, the brush ring 44 has mobility in the radial direction, and there is also a certain buffer space for the brush ring 44, which can enhance its stability while ensuring the sealing performance of the structure and extend the service life.

[0048] In this embodiment, since the ability of the labyrinth seal to withstand the upstream and downstream pressure differences is much greater than that of the brush seal, a plurality of labyrinth teeth 48 and a plurality of brush rings 44 are arranged in an alternating manner. Specifically, the number of labyrinth teeth on the labyrinth disc 45 is 4, and the number of stages of the brush ring 44 is 3, so that a layer of labyrinth seal is provided behind each layer of brush seal, thereby enhancing the pressure-bearing capacity of each layer of brush seal, enhancing the pressure-bearing capacity of the overall brush seal, and further strengthening the stability of the overall structure.

[0049] Working principle of this embodiment: When the labyrinth disc 45 rotates, relative movement occurs between the labyrinth disc 45 and the mounting seat 41. When the brush ring 44 is under the action of the upstream and downstream pressure differences, it will tilt axially towards the direction with a lower pressure drop. Due to the structural characteristics of the bottom wall surface of the tooth cavity 49, the brush ring 44 will receive a radially outward force. At the same time, when the labyrinth disc 45 undergoes radial runout or deformation, the brush ring 44 will also receive a radially outward force, and the brush ring 44 will be squeezed between the tooth cavity 49 and the mounting groove 47, causing the brush ring 44 to squeeze the metal seal ring 43. Due to the certain resilience of the metal seal ring 43, the contact pressure between the brush ring 44 and the inner wall of the tooth cavity 49 is buffered and reduced to a certain extent, enhancing the sealing performance of the brush seal and extending the service life of the brush ring 44; furthermore, the labyrinth seal formed by the combination of the labyrinth teeth 48 and the honeycomb ring 42 ensures the sealing performance while enhancing the pressure-bearing capacity of the overall structure. The staggered arrangement of multiple layers of labyrinth seals and multiple layers of brush seals enhances the gas flow dissipation effect and friction effect of the overall structure, weakens the ventilation effect, and further improves the sealing effect of this structure.

[0050] The preferred embodiment of the present invention also provides an installation method for a labyrinth-brush composite sealing device with self-adaptability and high sealing performance, including the following steps:

[0051] S1: Connect the labyrinth disc 45 to the rotating part 3, and then jointly install the labyrinth disc 45 and the rotating part 3 on the engine rotating shaft.

[0052] S2: First, install each arc segment in each metal seal ring 43 into the corresponding mounting groove 47 respectively, and then install each arc segment in each brush ring 44 into the corresponding mounting groove 47 respectively, so that the brush ring 44 and the metal seal ring 43 in the same mounting groove 47 are in contact, and at this time, the metal seal ring 43 is not extruded by external forces.

[0053] S3: Then, fix each arc segment in each honeycomb ring 42 to the inner wall surface of the corresponding sealing cavity 46 by brazing, so that the tips of the opposite labyrinth teeth 48 are in clearance fit with the honeycomb ring 42.

[0054] S4: Connect any two arc segments on each mounting seat 41 through the ear blocks of the bolt connection outer ring to form a semi-circular mounting seat 41.

[0055] S5: Assemble the mounting seats 41 of the semi-circular arc segments together in the flow path inner casing 2. The inner rings of the mounting seats 41 are oppositely installed with one side of the labyrinth teeth 48 of the labyrinth disc 45, so that the end of the brush ring 44 away from the mounting groove 47 contacts the bottom of the tooth cavity 49.

[0056] Embodiment 2

[0057] Based on Embodiment 1, the metal sealing ring 43 can also be set as an O shape.

[0058] Embodiment 3

[0059] Based on Embodiment 1, the metal sealing ring 43 can also be set as a C shape.

[0060] Embodiment 4

[0061] Based on Embodiment 1, the metal sealing ring 43 can also be set as an Ω shape.

[0062] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A comb brush type composite sealing device with self-adaptability and high sealing performance, characterized in that: It comprises a comb tooth plate (45), wherein a tooth cavity (49) is formed between two adjacent comb teeth (48) on the comb tooth plate (45); It also includes a mounting seat (41), wherein the inner ring of the mounting seat (41) is provided with a plurality of sealing cavities (46), the inner ring of the mounting seat (41) is arranged opposite to one side of the comb teeth (48) on the comb tooth plate (45), and the plurality of sealing cavities (46) correspond one to one to the plurality of comb teeth (48); The mounting seat (41) is provided with a mounting groove (47) between two adjacent sealing cavities (46); the plurality of mounting grooves (47) correspond one to one with the plurality of tooth cavities (49); a metal sealing ring (43) is arranged in the mounting groove (47); and a brush ring (44) is arranged between the tooth cavity (49) and the metal sealing ring (43).

2. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The metal sealing ring (43) is configured to be in a W shape, an O shape, a C shape or an Ω shape.

3. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: A honeycomb ring (42) is arranged in the sealing cavity (46), and a clearance fit is provided between the honeycomb ring (42) and the tooth tops of the comb teeth (48).

4. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The mounting seat (41), the metal sealing ring (43) and the brush ring (44) are all composed of four equally divided circular arc segments.

5. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The plurality of comb teeth (48) and the plurality of brush rings (44) are arranged in a staggered manner.

6. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The inner wall of the bottom of the tooth cavity (49) is provided with a wear-resistant coating (410).

7. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The number of grate teeth on the grate tooth plate (45) is 4 teeth.

8. The comb-tooth brush type composite sealing device with self-adaptability and high sealing performance as claimed in claim 1, characterized in that: The brush ring (44) is composed of a brush bundle (4401), a front baffle (4402) and a rear baffle (4403); the front baffle (4402) and the rear baffle (4403) are respectively fixedly arranged on both sides of the brush bundle (4401); the width of the front baffle (4402) is smaller than the width of the rear baffle (4403), and the width of the rear baffle (4403) is smaller than the width of the brush bundle (4401).

9. The method for installing a comb-tooth brush type composite sealing device with self-adaptability and high sealing performance according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Connect the grate plate (45) to the rotating member (3), and then install the grate plate (45) and the rotating member (3) together on the rotating shaft of the engine; S2: First, each arc segment in each metal sealing ring (43) is installed into the corresponding installation groove (47), and then each arc segment in each brush ring (44) is installed into the corresponding installation groove (47), so that the brush ring (44) in the same installation groove (47) is in contact with the metal sealing ring (43), and at this time, the metal sealing ring (43) is not squeezed by external force; S3: fixing each arc segment in each honeycomb ring (42) to the inner wall surface of the corresponding sealing cavity (46) by brazing, so that the tooth tops of the opposite comb teeth (48) are in clearance fit with the honeycomb ring (42); S4: Connecting any two arc segments on each mounting seat (41) to the ear blocks of the outer ring by bolts to form a mounting seat (41) with a semi-circular arc segment; S5: The semicircular arc segment mounting seat (41) is assembled together on the inner casing (2) of the flow channel, and the inner ring of the mounting seat (41) is mounted opposite to one side of the comb teeth (48) of the comb tooth plate (45), so that the end of the brush ring (44) away from the mounting groove (47) contacts the bottom of the tooth cavity (49).

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