A brush seal wiper plate and welding method

Abstract

The application belongs to the technical field of sealing, and particularly relates to a brush seal row wire core plate and a welding method. In view of the problems of complicated row wire process, small metallurgical bonding range and limited brush wire density of the existing brush seal, an ultra-thin circular ring row wire core plate made of nickel-based high-temperature alloy is adopted, an edge with a 45-degree angle with the radial direction is punched, a groove is formed between the edges to accommodate the brush wire, a single layer of core plate carries a layer of brush wire ring, and the multiple layers of core plates can be axially stacked and clamped between the annular front plate and the back plate. An electron beam is vertically injected from the upper surface of the back plate, and is welded along the annular track to form a brush seal structure. Compared with the prior art, the application provides a simplified row wire method and a welding method for improving the metallurgical bonding range of the brush wire and the back plate, ensures that the brush wire is not easy to fall off, enhances the stability and sealing effect of the structure, and is suitable for the sealing manufacturing of power devices such as an aero-engine and a gas turbine.

Description

Technical Field

[0001] This invention belongs to the field of sealing technology, specifically a brush seal wire core plate and welding method. Background Technology

[0002] Brush seals are a type of contact-type dynamic sealing technology with excellent sealing performance developed in recent years. Their leakage rate is 10%–20% lower than that of traditional non-contact labyrinth seals, and they increase rotor stability. They are currently widely used in high-end power plants, such as aero-engines and gas turbines. A brush seal consists of high-performance metal wires and supporting front and back plates. The brush wires are tightly arranged to form a brush ring. The end of the brush wire bundle closest to the shaft is a free end, contacting the shaft surface, while the end closest to the outer circumference of the brush ring is a fixed end. The brush wire bundle is typically welded to the front and back plates using a vacuum electron beam. However, the arrangement of the brush wires and the subsequent welding process present a series of challenges and usually require specialized equipment and cumbersome procedures. First, to adapt to the rotor's rotation direction and reduce wear, the brush wires need to be neatly arranged and at a certain radial angle, which is difficult to achieve with metal wires possessing a certain degree of rigidity. Secondly, during the welding process, the electron beam is usually injected radially from the outer circumference. In this way, it is difficult to fix the brush filaments, and the metallurgical bonding range between the brush filaments and the backing plate is small, which easily leads to phenomena such as brush filament misalignment, bending, and detachment. In addition, since the width of the molten pool in electron beam welding is limited, the thickness of the brush filament bundle should not be too high, which restricts the density of the brush filaments in the circumferential direction.

[0003] The patent with publication number CN102922121A proposes a vacuum electron beam welding method for a brush-type sealing ring assembly. It uses a tooling to clamp the brush filaments and the back plate, and injects the electron beam for welding from the outer circumference radially. The filament arrangement relies entirely on the special tooling, which is cumbersome. After the tooling is removed, the brush filaments are not continuously positioned, and they are prone to displacement during the welding process. The electron beam is injected from the radial outer circle, and the metallurgical bonding surface between the brush filaments and the back plate is a radial surface, which has a small bonding range and makes the brush filaments easy to fall off.

[0004] The patent with publication number CN121608085A proposes a wire-laying clamp and its wire-laying device for the wire winding and laying process of brush seals. This clamp is a process auxiliary tooling and needs to be removed after the wire laying is completed. It does not constitute a component of the sealing product and cannot continuously position the brush filaments during welding and use. It can only lay a single layer of brush filaments and does not have the capacity for multi-layer stacking and bearing, and cannot improve the brush filament density of a single-stage seal.

[0005] The patent with publication number CN114991883A proposes a radial multi-layer brush-type sealing structure, which uses U-shaped brushes with inner and outer radial layers and is fixed with an intermediate clamping plate. The layering direction is radial, and an intermediate clamping plate and multiple sets of groove plates are required. The overall structure is complex and the axial dimension is large. The brushes are U-shaped with fixed ends, and the arrangement process is complex. It is impossible to achieve multi-layer stacking by simply laying them flat.

[0006] The patent with publication number CN121535379A proposes a method for welding heterogeneous materials in a brush-type sealing structure. A groove is opened on the inner side of the back plate to fill the brush filaments. An electron beam is applied vertically to the contact area for welding. The groove is directly machined on the thick-walled back plate body, which has high processing costs and can only accommodate a single layer of brush filaments, making it impossible to achieve multi-layer stacking. There is no independent filament core plate component, and the positioning of the brush filament angle depends entirely on the groove of the back plate, resulting in poor product design flexibility.

[0007] The patent with publication number CN103883363A proposes a non-contact brush seal and its manufacturing method. It uses a wire arrangement tool with positioning groove to achieve a 45° brush filament arrangement and uses laser welding. The wire arrangement tool is a detachable structure and needs to be removed after wire arrangement, which is a complicated process. It only uses a single-layer brush filament structure, which limits the improvement of sealing performance.

[0008] The patent with publication number CN201314245Y proposes a wire arrangement machine for a brush sealing device. It achieves 45° angle positioning of the brush filaments through a partition, but can only achieve manual arrangement of a single layer of brush filaments. This results in low efficiency, poor precision, and cannot solve the problems of brush filament welding failure and insufficient density.

[0009] Therefore, based on the aforementioned problems, it is necessary to design a brush-sealed wire core plate and a welding method. Summary of the Invention

[0010] To address the problems of complex wire arrangement process, poor welding quality, and limited filament density in existing brush seals, the present invention aims to provide a wire arrangement core plate and welding method for brush seals, which simplifies the wire arrangement process and improves the reliability and sealing performance of the welded parts.

[0011] The technical solution of the present invention is as follows:

[0012] A brush-type sealing wire core plate, wherein the wire core plate is made of nickel-based high-temperature alloy ultra-thin sheet material processed into a ring shape, and ridges are punched on the core plate at intervals by a mold. The included angle between the ridges and the radial direction of the core plate is 45°. Grooves are formed between the ridges to accommodate and position the brush filament bundles. The brush filament bundles are laid flat in the grooves to form a single layer of brush filament rings.

[0013] The brush-sealed wire core plate has a thickness of 0.08–0.15 mm and an edge height of 0.3–0.4 mm.

[0014] The thickness of the brush-sealed wire guide plate is less than 0.1 mm.

[0015] The brush-sealed core plate has brush filaments with a diameter of 0.135 mm laid flat in the groove.

[0016] A brush-type sealing welding method using the aforementioned wire guide core plate includes the following steps:

[0017] Step 1: Evenly spread the bristle bundle in the groove of the bristle core plate to form a single-layer bristle ring, and place the bristle ring on the front plate.

[0018] Step 2: Based on the maximum melting depth of the electron beam, the core plate carrying the brush filaments is axially stacked in multiple layers to form a multi-layer brush filament ring structure.

[0019] Step 3: Cover the top of the brush bristle ring with a back plate, and clamp all the brush bristle bundles and the bristle core plate by axial constraint between the front plate and the back plate.

[0020] Step four: An electron beam is injected from the upper surface of the back plate. The electron beam moves along a circular trajectory and eventually returns to the starting point, completing the welding and forming a brush-type sealing structure.

[0021] In the brush-type sealing welding method, in step two, the number of stacked brush filament rings is 3 to 6 layers, and the brush filament density along the circumferential direction is 70 to 130 filaments / mm.

[0022] The brush-type sealing welding method described above uses AISI 410 stainless steel for both the front and back plates, with smooth surfaces.

[0023] In the brush-type sealing welding method, in step three, the annular back plate and front plate are symmetrically arranged on both sides of the brush bristle ring. The brush bristle bundle is clamped by the axial alignment of the front plate and the back plate to form an axially stacked structure of the front plate, multi-layer brush bristle ring, and back plate.

[0024] In the brush-type sealing welding method, in step four, the electron beam is vertically injected into the outer circular area of ​​the upper surface of the back plate corresponding to the fixed end of the brush filament, and the moving trajectory is a ring concentric with the filament core plate.

[0025] The design concept of this invention is:

[0026] This invention simplifies the wire arrangement process and improves the reliability of welded parts by designing a novel wire arrangement core plate. The core plate is made of an ultra-thin nickel-based high-temperature alloy, forming a circular ring shape. Ridges are stamped at appropriate intervals using a die, with the ridges forming a 45° angle with the radial direction. Grooves are formed between the ridges to facilitate the arrangement of the brush filament bundles. The brush filament bundles are evenly laid out in the grooves of the core plate to form brush filament rings. These rings are placed on a front plate, and multiple layers can be stacked to increase the brush filament density. A back plate is then placed on top, and the brush filament bundles are clamped and constrained by the back plate and the front plate. An electron beam is injected into the upper surface of the back plate for welding, forming a brush-type sealing structure.

[0027] This application transforms the filament positioning function from a detachable tooling into a product component. It uses annular core plates with 45° inclined grooves stamped from ultra-thin nickel-based high-temperature alloy sheets. The grooves can directly constrain the arrangement angle and position of the brush filaments, allowing for flat arrangement without the need for dedicated filament arrangement equipment. This core plate also serves as a layered base, enabling the axial stacking of multiple layers of brush filament rings. Combined with the clamping structure of the front plate and back plate, the brush filament density is significantly increased within a single-stage sealed cavity. Correspondingly, annular electron beam welding technology, which is vertically injected from the upper surface of the back plate, is used to fully fuse the fixed ends of the back plate and multi-layer core plates with the ends of the brush filaments, fundamentally increasing the metallurgical bonding range and improving welding strength and structural reliability.

[0028] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0029] 1. This invention simplifies the bristle arrangement process by incorporating a specific bristle core plate. The core plate's built-in groove structure achieves angular positioning and uniform bristle distribution, eliminating the need for specialized bristle arrangement equipment and complex tooling. This reduces process difficulty and manufacturing costs. Furthermore, it allows for the stacking of bristle rings, increasing bristle density and reducing the space occupied by the front and back plates, further enhancing the sealing effect. Simultaneously, it allows the electron beam to penetrate from the surface, increasing the metallurgical bonding range between the bristles and the back plate, making the bristles less prone to detachment.

[0030] 2. The present invention significantly improves the density of brush filaments, and can achieve axial stacking of 3 to 6 layers of brush filaments according to the electron beam melting depth. The density of brush filaments along the circumferential direction can reach 70 to 130 filaments / mm, which enhances the sealing effect in a limited space.

[0031] 3. The welding reliability of this invention is significantly enhanced. The electron beam enters vertically from the surface of the back plate, and the metallurgical bonding range between the brush filaments and the back plate and core plate is larger. The brush filaments are less likely to deviate, bend or fall off, and the structural stability is improved.

[0032] 4. The present invention has a compact structure and occupies little space. The ultra-thin core plate hardly occupies any additional axial space. Compared with the traditional multi-stage sealing and radial multi-layer structure, it greatly reduces the axial dimension and reduces the space occupied by the front plate and back plate. Attached Figure Description

[0033] To more clearly illustrate the technical solution provided by the present invention, the accompanying drawings will be briefly described below.

[0034] Figure 1 This is a schematic diagram of the overall wire-laying core plate in this invention.

[0035] Figure 2 This is a schematic diagram of the brush filaments arranged on the core board in this invention.

[0036] Figure 3 This is a schematic diagram of the stacking and welding of brush filament rings in this invention.

[0037] Figure 4 This is a schematic diagram of the brush seal structure of the present invention.

[0038] In the diagram: 1-Wire core plate; 2-Edge; 3-Groove; 4-Brush bristles; 5-Front plate; 6-Back plate; 7-Electron beam injection direction; 8-Electron beam movement trajectory. Detailed Implementation

[0039] In practical implementation, this invention proposes a brush-sealed wire-laying core plate, the specific structure of which is as follows:

[0040] (1) The wire core plate is made into a circular shape and is made of nickel-based high-temperature alloy ultra-thin material;

[0041] (2) A ridge at a 45° angle to the radial direction is punched out on the wire core plate using a die;

[0042] (3) Grooves are formed between the edges to accommodate and arrange the bristle bundles.

[0043] A single wire guide core plate and the brush filament bundles inside its groove together form a brush filament ring assembly. Multiple brush filament ring assemblies are stacked axially and clamped between a circular front plate and a circular back plate. After electron beam welding, a complete brush seal is formed. The wire guide core plate, as an internal component of the brush seal structure, remains inside the product after welding.

[0044] The welding method of the wire guide core plate includes the following steps:

[0045] (1) Prepare the front plate and the back plate, both of which are made of AISI 410 stainless steel and polish the surface smooth; spread the brush bristles evenly in the groove of the bristle core plate to form a single layer of brush bristle rings, and place the brush bristle rings on the front plate.

[0046] (2) Based on the maximum melting depth of the electron beam, multiple layers of wire core plates carrying brush filaments are stacked sequentially along the axial direction. The number of stacked layers is 3 to 6, and the brush filament density along the circumferential direction after stacking can reach 70 to 130 filaments / mm.

[0047] (3) A back plate is placed on top of the uppermost brush ring. The front plate and the back plate are aligned axially to constrain and clamp all the brush bundles and the brush core plate.

[0048] (4) Vacuum electron beam welding process is adopted. The electron beam is injected vertically from the upper surface of the back plate, and the injection position corresponds to the outer circle area of ​​the brush wire fixing end. The electron beam moves along a circular trajectory concentric with the wire core plate and eventually returns to the starting point to ensure welding quality, so that the outer circle of the back plate and each layer of wire core plate is fully fused with the brush wire fixing end to form a complete brush sealing structure.

[0049] like Figure 1As shown, the wire core plate 1 is an ultra-thin nickel-based high-temperature alloy with a thickness of 0.08 to 0.15 mm. It is processed into a ring shape, with the outer diameter being smaller than the outer diameter of the back plate or front plate and the inner diameter being larger than the inner diameter of the back plate or front plate. Ribs 2 with a height of 0.3 to 0.4 mm are stamped out at appropriate intervals using a mold. The angle between the ribs 2 and the radial direction is 45°. Grooves 3 are formed between adjacent ribs.

[0050] like Figure 2 As shown, the brush bristles 4 are cobalt-based high-temperature alloy filaments with a diameter of about 0.135 mm. The brush bristle bundle is evenly and densely laid in the groove 3 of the bristle core plate 1 to form a layer of brush bristle ring.

[0051] In this invention, the wire core plate 1 is a ring-shaped solid thin plate made of nickel-based high-temperature alloy, with ridges 2 and grooves 3 stamped on it. Using the wire core plate 1 as a carrier, the brush ring is a functional sealing layer formed by arranging cobalt-based high-temperature alloy brush filaments flatly in the grooves 3 of a single wire core plate 1, and is positioned by relying on the wire core plate 1. A single wire core plate 1 and the brush filaments inside its grooves 3 together constitute a brush ring assembly. Multiple sets of brush ring assemblies are stacked axially and clamped between the ring-shaped front plate 5 and the ring-shaped back plate 6, and formed into a brush-type sealing product by electron beam welding.

[0052] like Figure 3 As shown, the front plate 5 and the back plate 6 are made of AISI 410 stainless steel with a smooth surface. The brush ring is placed on the front plate. Depending on the maximum melting depth of the electron beam, 3 to 6 layers can be stacked. The brush density along the circumferential direction can reach 70 to 130 brushes / mm. The last layer is the back plate. The annular back plate 6 and the front plate 5 are symmetrically arranged on both sides of the brush ring. The brush bundle is clamped by the axial alignment of the front plate 5 and the back plate 6 to form an axially stacked structure of the front plate 5, multiple brush ring assemblies, and the back plate 6. The electron beam injection direction 7 is perpendicular to the outside of the back plate 6. The electron beam is injected perpendicularly into the back plate 6 for welding.

[0053] like Figure 4 As shown, the electron beam is vertically injected from the outer circular area of ​​the upper surface of the back plate 6 and welded along the electron beam movement trajectory 8. The electron beam movement trajectory 8 is an annular weld concentric with the wire guide core plate 1, corresponding to the brush wire fixing end area, realizing the metallurgical bonding of the back plate, the wire guide core plate and the brush wire end to form a brush-type sealing structure. The wire guide core plate 1, as a component of the brush-type sealing structure, is retained inside the product after welding, and has the functions of wire positioning, layered load bearing and welding reinforcement.

[0054] The present invention will be further described in detail below through embodiments.

[0055] Example 1

[0056] In this embodiment, the wire guide core plate is made of a 0.09mm thick nickel-based high-temperature alloy sheet, machined into a ring shape. Edges with a height of 0.36mm are stamped out using a die, with an angle of 45° between the edges and the radial direction. Grooves are formed between adjacent edges, with the groove width suitable for cobalt-based high-temperature alloy brush filaments with a diameter of 0.135mm. Both the front and back plates are made of AISI 410 stainless steel, with surfaces polished to a smooth, oxide-free finish.

[0057] The welding preparation process is as follows: Cobalt-based high-temperature alloy brush filament bundles are evenly laid in the grooves of the wire-laying core plate to form a single-layer brush filament ring, which is then placed on the front plate. Three layers are axially stacked, resulting in three sets of brush filament ring assemblies. After stacking, the brush filament density along the circumferential direction is 70-90 filaments / mm. A back plate is placed over the top layer of brush filament rings, and all assemblies are axially clamped between the front plate and the back plate. Vacuum electron beam welding is used, with the electron beam perpendicularly entering from the outer circumference of the upper surface of the back plate, moving along a circular trajectory concentric with the core plate, and returning to the starting point. After welding, a brush-type sealing structure is obtained. This embodiment features a simple wire-laying process, accurate brush filament positioning, and firmly fixed brush filaments after welding, making it suitable for applications with moderate sealing requirements.

[0058] Example 2

[0059] In this embodiment, the wire guide core plate is made of a 0.1mm thick nickel-based high-temperature alloy sheet, machined into a ring shape. Edges with a height of 0.3mm are stamped out using a die, with the angle between the edges and the radial direction being 45°. Grooves are formed between adjacent edges, with the groove width suitable for cobalt-based high-temperature alloy brush filaments with a diameter of 0.135mm. Both the front and back plates are made of AISI 410 stainless steel, with surfaces polished to a smooth, oxide-free finish.

[0060] The welding preparation process is as follows: Cobalt-based high-temperature alloy brush filament bundles are evenly laid in the grooves of the wire core plate to form a single-layer brush filament ring, which is then placed on the front plate. Four layers are axially stacked, resulting in four sets of brush filament ring assemblies. After stacking, the brush filament density along the circumferential direction is 90–110 filaments / mm. A back plate is placed over the top layer of brush filament rings, and all assemblies are axially clamped between the front plate and the back plate. Vacuum electron beam welding is used, with the electron beam perpendicularly entering from the outer circumference of the upper surface of the back plate, moving along a circular trajectory concentric with the core plate, and returning to the starting point. After welding, a brush-type sealing structure is obtained. This embodiment achieves higher brush filament density within a compact axial space, resulting in excellent sealing performance and high weld strength, making it suitable for power unit operating conditions with high sealing requirements.

[0061] Example 3

[0062] In this embodiment, the wire guide core plate is made of a 0.08mm thick nickel-based high-temperature alloy sheet, machined into a ring shape. Edges with a height of 0.4mm are stamped out using a die, with the angle between the edges and the radial direction being 45°. Grooves are formed between adjacent edges, with the groove width suitable for cobalt-based high-temperature alloy brush filaments with a diameter of 0.135mm. Both the front and back plates are made of AISI 410 stainless steel, with surfaces polished to a smooth, oxide-free finish.

[0063] The welding preparation process is as follows: Cobalt-based high-temperature alloy brush filament bundles are evenly laid in the grooves of the wire core plate to form a single-layer brush filament ring, which is then placed on the front plate. Six layers are axially stacked, resulting in six sets of brush filament ring assemblies. After stacking, the brush filament density along the circumferential direction is 110-130 filaments / mm. A back plate is placed over the top layer of brush filament rings, and all components are axially clamped between the front plate and the back plate. Vacuum electron beam welding is used, with the electron beam perpendicularly entering from the outer circumference of the upper surface of the back plate, moving along a circular trajectory concentric with the core plate, and returning to the starting point. After welding, a brush-type sealing structure is obtained. This embodiment has the highest brush filament density, the best sealing effect, and the ultra-thin core plate minimizes space occupation. The overall structure after welding is reliable and suitable for high-end power unit operating conditions with high sealing requirements.

[0064] The results show that, compared with the prior art, the present invention provides a simplified filament arrangement method and a welding method that improves the metallurgical bonding range between the brush filaments and the back plate, ensuring that the brush filaments are not easily detached and enhancing the stability and sealing effect of the structure.

[0065] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application, such as core board material, thickness, groove width, front plate and back plate materials, should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A brush-sealed wire-laying core plate, characterized in that, The core plate is made of nickel-based high-temperature alloy ultra-thin sheet material and processed into a ring shape. Ridges are punched out on the core plate at intervals by a mold. The angle between the ribs and the radial direction of the core plate is 45°. Grooves are formed between the ribs to accommodate and position the brush filament bundles. The brush filament bundles are laid flat in the grooves to form a single layer of brush filament rings.

2. The brush-sealed wire-laying core plate according to claim 1, characterized in that, The thickness of the wire core plate is 0.08 to 0.15 mm, and the height of the edge is 0.3 to 0.4 mm.

3. The brush-sealed wire core plate according to claim 2, characterized in that, The thickness of the wire core plate is less than 0.1 mm.

4. The brush-sealed wire-laying core plate according to claim 1, characterized in that, The brush filaments laid flat in the groove are cobalt-based high-temperature alloy filaments with a diameter of 0.135 mm.

5. A brush-type sealing welding method using the wire-laying core plate according to any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Evenly spread the bristle bundle in the groove of the bristle core plate to form a single-layer bristle ring, and place the bristle ring on the front plate. Step 2: Based on the maximum melting depth of the electron beam, the core plate carrying the brush filaments is axially stacked in multiple layers to form a multi-layer brush filament ring structure. Step 3: Cover the top of the brush bristle ring with a back plate, and clamp all the brush bristle bundles and the bristle core plate by axial constraint between the front plate and the back plate. Step four: An electron beam is injected from the upper surface of the back plate. The electron beam moves along a circular trajectory and eventually returns to the starting point, completing the welding and forming a brush-type sealing structure.

6. The brush seal welding method according to claim 5, characterized in that, In step two, the number of stacked bristle rings is 3 to 6, and the bristle density along the circumference is 70 to 130 bristles / mm.

7. The brush seal welding method according to claim 5, characterized in that, Both the front and back panels are made of AISI410 stainless steel with a smooth surface finish.

8. The brush seal welding method according to claim 5, characterized in that, In step three, the annular back plate and front plate are symmetrically arranged on both sides of the bristle ring. The bristle bundle is clamped by the axial alignment of the front plate and the back plate, forming an axially stacked structure of the front plate, multi-layer bristle ring, and back plate.

9. The brush seal welding method according to claim 5, characterized in that, In step four, the electron beam is perpendicularly injected into the outer circular area of ​​the upper surface of the back plate corresponding to the fixed end of the brush bristles, and its movement trajectory is a ring concentric with the bristle core plate.

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