Brush seal with graphite shoe structure and method of making

Abstract

The application discloses a brush seal with a graphite booting structure and a manufacturing method thereof, and the manufacturing method comprises the following steps: preparing a basic brush seal and a tool clamp, and fixing the basic brush seal in the tool clamp; fixing the tool clamp with the assembled basic brush seal on a speed-adjustable rotary table, and adjusting the working speed; then, spraying the nickel-coated graphite powder, which is heated to be melted, into the spraying cavity by using a flame spraying gun, so that the graphite booting structure is formed at the end of the brush bundle, wherein the spraying surface of the nickel-coated graphite is cooled by using a wind cooling device during the spraying process; performing finishing processing on the graphite booting structure at the end of the brush bundle; and disassembling the tool clamp to obtain the brush seal with the graphite booting structure. The manufacturing method of the brush seal with the graphite booting structure is convenient to implement, the manufactured brush seal has high reliability, high wear resistance and long service life.

Description

Technical Field

[0001] This invention belongs to the field of brush seals between rotating shafts, and specifically provides a brush seal with a graphite boot structure and its manufacturing method. Background Technology

[0002] Brush seals offer superior sealing performance compared to traditional comb-type non-contact seals. They also exhibit greater adaptability to rotor radial runout compared to graphite seals. Therefore, brush seals meet the sealing requirements for areas between rotating shafts. However, when a basic brush seal is applied to these areas, the brush filaments tend to expand radially outward under the centrifugal force of the high-speed rotor. This can lead to reduced overall sealing performance (when the brush filaments are installed on an outer rotor), increased brush filament wear, and a shortened service life of the brush seal. To address these issues, existing technologies have proposed a boot-type brush seal structure, fixing a brush filament fixing boot to the free end of the brush filament bundle. However, fixing the brush filament bundle and the brush filament fixing boot presents the following technical problems: First, existing technologies do not disclose non-metallic brush filament fixing boots or effective methods for fixing them to the brush filaments. If a metallic material is chosen for the brush filament fixing boot, fixing the brush filament bundle and the brush filament fixing boot by welding is difficult, resulting in low reliability between the welded brush filament bundle and the brush filament fixing boot. Furthermore, the metallic brush filament fixing boot has poor friction and wear resistance.

[0003] Therefore, proposing a brush seal with a graphite boot structure and its manufacturing method to facilitate the fixing of the brush filament bundle and the brush filament fixing boot, improve the connection reliability between the brush filament bundle and the brush filament fixing boot, and improve the friction and wear resistance of the brush filament fixing boot have become urgent problems to be solved. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide a brush seal with a graphite boot structure and its manufacturing method, so as to solve the problems of high difficulty in fixing the existing brush filament bundle and brush filament fixing boot, low connection reliability, and poor friction and wear resistance.

[0005] This invention provides a method for manufacturing a brush seal with a graphite bootstyling structure, comprising:

[0006] Prepare a basic brush seal and a tooling fixture, and fix the basic brush seal within the tooling fixture. The basic brush seal includes a connecting ring, a front baffle, a rear baffle, and a bristle bundle. The front baffle, bristle bundle, and rear baffle are sequentially connected to the connecting ring along its axial direction. The tooling fixture includes a fixture body and a spray baffle. The fixture body is a split structure and forms a ring when joined. A placement groove for the basic brush seal is provided in the middle of the fixture body. The spray baffle includes a front spray baffle that mates with the front baffle and a rear spray baffle that mates with the rear baffle. Both the front and rear spray baffles are split structures and are bolted to the fixture body. The front and rear spray baffles limit and fix the basic brush seal within the fixture body and form a spray cavity at the free end of the bristle bundle.

[0007] The tooling fixture with the assembled basic brush seal is fixed on the speed-regulating turntable and the speed-regulating turntable is adjusted to the working speed. Then, the nickel-coated graphite powder heated to molten is sprayed into the spraying chamber using a flame spray gun, so that the molten nickel-coated graphite powder is deposited layer by layer in the gaps and surface of the brush filament bundle, forming a graphite boot structure at the end of the brush filament bundle. During the spraying process, the nickel-coated graphite sprayed surface is cooled by an air-cooling device.

[0008] The graphite boots-like structure at the tip of the brush filament bundle is precision machined;

[0009] Disassemble the tooling fixture to obtain a brush seal with a graphite boot structure.

[0010] Further preferably, the bottom of the placement groove of the clamp body is provided with a limiting groove that cooperates with the connecting ring.

[0011] In a further preferred embodiment, the front spraying baffle and the rear spraying baffle are respectively provided with limiting edges that cooperate with the front baffle and the rear baffle on the side close to the inner wall of the placement groove.

[0012] Further preferably, the front spraying baffle and the rear spraying baffle are provided with stepped structures on their opposite sides.

[0013] Further preferably, the nickel-coated graphite powder has a particle size of 0.010-0.005 mm, a bristle diameter of 0.07-0.10 mm, and a bristle gap of 0.007-0.010 mm.

[0014] The present invention also provides a brush seal with a graphite bootstyling structure, which is manufactured using the above-described method for manufacturing a brush seal with a graphite bootstyling structure.

[0015] The method for manufacturing a brush seal with a graphite booted structure provided by this invention is easy to operate. Molten nickel-coated graphite powder is sprayed onto the ends of the brush filament bundle using a flame spraying process and then cooled. This allows for the deposition of nickel-coated graphite powder in the gaps and on the surface of the brush filament bundle, thereby forming a graphite booted structure at the ends of the metal brush filaments. This method implants the metal brush filaments into the non-metallic booted structure in the form of hair follicles, improving the reliability between the free ends of the metal brush filament bundle and the non-metallic booted structure, and preventing separation and detachment. Furthermore, the graphite booted structure can further improve the wear resistance of the brush seal and extend its service life. When the brush seal with the graphite booted structure manufactured using this method is installed in a brush seal between rotating shafts, it can effectively suppress the outward expansion of the brush filaments due to centrifugal effect. Attached Figure Description

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0017] Figure 1 A schematic diagram of a 3 / 4 ring structure of a brush seal with a graphite boot structure provided by the present invention;

[0018] Figure 2 A schematic diagram of a 3 / 4 ring structure of another brush seal with a graphite boot structure provided by the present invention;

[0019] Figure 3 This is a cross-sectional view of a basic brush seal.

[0020] Figure 4 This is an assembly drawing of a basic brush seal and tooling fixture.

[0021] Figure 5 A cross-sectional view of the brush seal with graphite boots structure provided by the present invention. Detailed Implementation

[0022] The present invention will be further explained below with reference to specific implementation schemes, but this explanation does not limit the scope of the invention.

[0023] To address the problems existing in the prior art, the present invention provides a method for manufacturing a brush seal with a graphite boot structure, comprising:

[0024] S1: Prepare a basic brush seal and a tooling fixture, and fix the basic brush seal into the tooling fixture, wherein, as shown... Figure 3 As shown, the basic brush seal includes a connecting ring 1, a front baffle 2, a rear baffle 3, and a bristle bundle 4. The front baffle 2, the bristle bundle 4, and the rear baffle 3 are sequentially connected to the connecting ring 1 along its axial direction. Figure 4As shown, the tooling fixture includes a fixture body 6 and a spraying baffle 5. The fixture body 6 is a split structure and forms an overall ring after docking. The middle part of the fixture body 6 is provided with a placement groove that cooperates with the basic type brush seal. The spraying baffle 5 includes a front spraying baffle that cooperates with the front baffle 2 and a rear spraying baffle that cooperates with the rear baffle 3. Both the front spraying baffle and the rear spraying baffle are split structures and are connected to the fixture body 6 by bolts. The front spraying baffle and the rear spraying baffle limit and fix the basic type brush seal in the fixture body 6 and form a spraying cavity at the free end of the brush filament bundle 4.

[0025] As an improvement to the technical solution, the bottom of the placement groove of the fixture body 6 is provided with a limiting groove (such as...) that cooperates with the connecting ring 1. Figure 4 As shown), it is used to limit the axial movement of the basic type brush seal.

[0026] As an improvement to the technical solution, the front spraying baffle and the rear spraying baffle are respectively provided with limiting edges (not shown in the figure) that cooperate with the front baffle 2 and the rear baffle 3 on the side close to the inner wall of the placement groove, which are used to limit the axial movement of the basic type brush seal.

[0027] After the spraying baffle 5 and the fixture body 6 are fixedly connected by bolts, the basic type brush seal is limited and fixed inside the tooling fixture.

[0028] To ensure that the graphite boot-like structure formed after spraying axially wraps around the ends of the brush filament bundle, as an improvement to the technical solution, stepped structures (such as...) are provided on opposite sides of the front and rear spraying baffles. Figure 4 (As shown).

[0029] S2: Fix the tooling fixture with the assembled basic brush seal on the speed-regulating turntable and adjust the speed-regulating turntable to the working speed. Then, use a flame spray gun to spray the heated and molten nickel-coated graphite powder into the spraying chamber, so that the molten nickel-coated graphite powder is deposited layer by layer in the gaps and on the surface of the brush filament bundle 4, forming a graphite boot structure 7 at the end of the brush filament bundle 4. During the spraying process, the nickel-coated graphite sprayed surface is cooled by an air-cooling device.

[0030] Nickel-coated graphite powders are composite powders consisting of graphite particles as the core and coated with metallic nickel. They possess excellent lubrication and corrosion resistance. They are produced using a wet hydrogen reduction process, where nickel is uniformly deposited onto the surface of graphite particles from a nickel sulfate ammonia complex solution. They can be used to manufacture high-temperature self-lubricating materials, low-friction materials, and for preparing wear-resistant coatings through spraying processes.

[0031] As an improvement to the technical solution, the nickel-coated graphite powder has a particle size of 0.010-0.005mm, a bristle diameter of 0.07-0.10mm, and a bristle gap of 0.007-0.010mm. The diameter of the nickel-coated graphite powder meets the requirement of filling the gap inside the bristles. When the nickel-coated graphite powder melts at high temperature, it can completely immerse itself in the bristle gap, implanting the bristles into the formed graphite boot structure in the form of hair follicles.

[0032] The flame spray gun, acting as a heat source, utilizes oxygen and acetylene as combustion-supporting and combustible gases. During the spraying process, nickel-coated graphite powder is delivered to the axial direction of the central combustion stream of the flame spray gun via a powder feeder. The nickel-coated graphite powder melts after being heated in the flame and then adheres to the flame spray velocity, depositing on the gaps between the brush filaments and on the surface. Through layer-by-layer deposition, a graphite boot-like structure is eventually formed.

[0033] During the spraying process, the nickel-coated graphite surface is cooled by air-cooling equipment to reduce the initial stress within the final nickel-coated graphite coating. The flame temperature of the flame spray gun can reach 3700℃, and at the moment of combustion, the temperature of the nickel-coated graphite particles can reach 700℃. The air-cooling equipment uses compressed air pipes to cool the nickel-coated graphite surface. The rotation of the turntable causes the brush tips of the brush seal to rotate at high speed. This high-speed airflow forces convection heat transfer, causing the temperature of the nickel-coated graphite surface to drop instantly. During the nickel-coated graphite spraying process, the temperature of the cooled surface can be controlled below 200℃.

[0034] S3: Perform fine machining on the graphite boots-like structure 7 at the end of the filament bundle 4;

[0035] Among them, fine machining can be achieved through CNC machine tools to improve the surface fineness of graphite boots and enhance the friction and wear resistance of the boots structure.

[0036] S4: Disassemble the tooling fixture to obtain a brush seal with a graphite boot structure, such as Figure 1 , Figure 2 , Figure 5 As shown.

[0037] The method for manufacturing this brush seal with a graphite booted structure is convenient. Molten nickel-coated graphite powder is sprayed onto the ends of the brush filament bundle using a flame spraying process and then cooled. This allows for the deposition of nickel-coated graphite powder in the gaps and on the surface of the brush filament bundle, thereby forming a graphite booted structure at the ends of the metal brush filaments. This method embeds the metal brush filaments into the non-metallic booted structure in the form of hair follicles, improving the reliability between the free ends of the metal brush filament bundle and the non-metallic booted structure, preventing separation and detachment. Furthermore, the graphite booted structure further enhances the wear resistance of the brush seal and extends its service life. When the brush seal with the graphite booted structure manufactured using this method is installed in a brush seal between rotating shafts, it effectively suppresses the outward expansion of the brush filaments due to centrifugal effect.

[0038] The present invention also provides a brush seal with a graphite bootstyling structure, which is manufactured using the above-described method for manufacturing a brush seal with a graphite bootstyling structure.

[0039] The specific embodiments of the present invention are written in a progressive manner, emphasizing the differences between the various implementation schemes, and the similar parts can be referred to each other.

[0040] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for manufacturing a brush seal with a graphite boot structure, characterized in that, include: Prepare a basic brush seal and a tooling fixture, and fix the basic brush seal in the tooling fixture. The basic brush seal includes a connecting ring (1), a front baffle (2), a rear baffle (3), and a brush bristle bundle (4). The front baffle (2), the brush bristle bundle (4), and the rear baffle (3) are sequentially connected to the connecting ring (1) along the axial direction of the connecting ring (1). The tooling fixture includes a fixture body (6) and a spray baffle (5). The fixture body (6) is a split structure and forms a ring when joined together. The fixture body (6) has a placement groove in the middle that cooperates with the basic type brush seal. The spraying baffle (5) includes a front spraying baffle that cooperates with the front baffle (2) and a rear spraying baffle that cooperates with the rear baffle (3). The front spraying baffle and the rear spraying baffle are both split structures and are connected to the fixture body (6) by bolts. The front spraying baffle and the rear spraying baffle limit and fix the basic type brush seal in the fixture body (6) and form a spraying cavity at the free end of the brush bundle (4). Fix the tooling fixture with the assembled basic brush seal on the speed-regulating turntable and adjust the speed-regulating turntable to the working speed. Then, use a flame spray gun to spray the heated and molten nickel-coated graphite powder into the spraying cavity, so that the molten nickel-coated graphite powder is deposited layer by layer in the gaps and surface of the brush filament bundle (4), forming a graphite boot structure (7) at the end of the brush filament bundle (4). During the spraying process, the nickel-coated graphite sprayed surface is cooled by an air-cooling device. The graphite boots-like structure (7) at the end of the filament bundle (4) is finely processed; Disassemble the tooling fixture to obtain a brush seal with a graphite boot structure.

2. The method for manufacturing a brush seal with a graphite boot structure according to claim 1, characterized in that: The bottom of the placement slot of the fixture body (6) is provided with a limiting groove that cooperates with the connecting ring (1).

3. The method for manufacturing a brush seal with a graphite boot structure according to claim 1, characterized in that: The front spraying baffle and the rear spraying baffle are respectively provided with limiting edges that cooperate with the front baffle (2) and the rear baffle (3) on the side close to the inner wall of the placement groove.

4. The method for manufacturing a brush seal with a graphite boot structure according to claim 1, characterized in that: The front and rear spraying baffles are provided with stepped structures on opposite sides.

5. The method for manufacturing a brush seal with a graphite boot structure according to claim 1, characterized in that: The nickel-coated graphite powder has a particle size of 0.010-0.005 mm, a bristle diameter of 0.07-0.10 mm, and a bristle gap of 0.007-0.010 mm.

6. A brush seal with a graphite bootstyling structure, characterized in that: It is manufactured using the method for manufacturing a brush seal with a graphite boot structure as described in any one of claims 1 to 5.

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