Radial adjustable brush type sealing structure with thermal response adjusting function

Abstract

The invention relates to the technical field of rotary mechanical sealing, in particular to a radial adjustable brush type sealing structure with a thermal response adjusting function, which comprises a plurality of arc-shaped sealing structures, and the end surfaces of the plurality of arc-shaped sealing structures are connected to form an annular brush type sealing structure; the arc-shaped sealing structure comprises an arc-shaped sealing case, an elastic supporting assembly and an axial limiting assembly. When the rotor radially jumps or the temperature changes, the arc-shaped sealing block can adaptively move in the guide limiting assembly to adaptively adjust the sealing gap between the brush wire bundle and the rotor, so that the sealing performance is improved, and the service life of the brush wires is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of rotary mechanical seals, and in particular to a radially adjustable brush seal structure with a thermal response adjustment function. Background Art

[0002] Brush seals are widely used in high-temperature, high-speed rotating equipment such as aircraft engines, gas turbines, and compressors due to their low friction loss, stable sealing performance, and compact structure. However, during operation, rotors can experience nonlinear runout due to thermal expansion, machining errors, or load disturbances. This can cause fluctuations in the clearance between the brush filaments and the rotor surface, leading to abnormal localized contact pressure, increased wear, and even seal failure.

[0003] Currently, most common brush seals are fixed, rigid structures that cannot adapt to dynamic changes in rotor operating conditions, especially under conditions of severe temperature fluctuations, where the seal gap changes uncontrollably. Furthermore, the brush bundles are typically arranged at an angle, making it difficult for traditional coaxial seal segments to accommodate full-directional runout, resulting in reduced sealing performance.

[0004] Therefore, it is necessary to provide a radially adjustable brush seal structure with a thermal response adjustment function to solve the above problems. Summary of the Invention

[0005] In order to solve the problems of brush wire wear and reduced leakage performance caused by radial vibration of the rotor in the current common brush seals, especially the uncontrollable change of the sealing gap under conditions of drastic temperature fluctuations, the present invention provides a radially adjustable brush seal structure with a thermal response adjustment function to solve the existing problems.

[0006] The radially adjustable brush seal structure with thermal response adjustment function of the present invention adopts the following technical solutions, including: Multiple arc-shaped sealing structures, end surfaces of the multiple arc-shaped sealing structures are connected to form an annular brush-type sealing structure; The arc sealing structure includes: The inner arc surface of the arc-shaped sealing casing is slidably connected to the arc-shaped sealing block through a guide and limit assembly; the guide and limit assembly is used to limit the movement of the arc-shaped sealing block in the radial direction and the position of the movement when the arc-shaped sealing block is subjected to force; An elastic support assembly, which is used for resetting the arc-shaped sealing block and supports the arc-shaped sealing block after resetting so that a first movable gap is formed between the outer arc surface of the arc-shaped sealing block and the inner arc surface of the arc-shaped sealing casing; An arc-shaped brush fixing block, which is arranged on the inner ring of the arc-shaped sealing block; and an axial limiting assembly for limiting the axial movement of the arc-shaped sealing block; Among them, the ends of the arc sealing blocks of two adjacent arc sealing structures in the annular brush sealing structure and the ends of the arc sealing casings of two adjacent arc sealing structures are axially staggered and connected, and a second movable gap is left between the end faces of the arc sealing blocks of two adjacent arc sealing structures.

[0007] According to a further technical solution of the present invention, the guide limit assembly includes: A plurality of guide posts are evenly distributed on the outer arc surface of the arc-shaped sealing block, and a first limiting protrusion is provided on the side surface of the free end of the guide post; and a plurality of guide grooves, which are evenly distributed on the inner arc surface of the arc-shaped sealing casing, and a second limiting protrusion is provided on the side wall of the guide groove facing the arc-shaped sealing block; The guide column is radially slidably arranged in the corresponding guide groove, and the first limiting protrusion and the second limiting protrusion form a limit for the moving position of the arc-shaped sealing block in the radial direction.

[0008] According to a further technical solution of the present invention, the elastic reset assembly includes: An elastic sheet is provided on the outer arc surface of the arc-shaped sealing block between every two adjacent guide pillars, one end of the elastic sheet is connected to the outer arc surface of the arc-shaped sealing block, and the other end of the elastic sheet is in contact with the inner arc surface of the arc-shaped sealing casing; And a tension spring, which is arranged in a mounting groove opened on the guide column, one end of which is connected to the bottom surface of the mounting groove, and the other end of which is connected to the bottom surface of the guide groove on the inner arc surface of the arc-shaped sealing casing.

[0009] According to a further technical solution of the present invention, the elastic sheet is made of shape memory alloy material.

[0010] A further technical solution of the present invention is that the shape of the elastic sheet is Ω-shaped, U-shaped, semi-arc-shaped, wavy or crescent-shaped with a curved surface, wherein the curved surface of the elastic sheet contacts the inner curved surface of the arc-shaped sealing casing, and the side facing away from the curved surface of the elastic sheet has two free ends, one of which is connected to the outer curved surface of the arc-shaped sealing block, and the other free end is connected to the outer curved surface of the arc-shaped sealing block in a circumferential sliding manner along the outer curved surface.

[0011] According to a further technical solution of the present invention, an accommodating groove for accommodating the elastic sheet is formed on the inner arc surface of the arc-shaped sealing casing, wherein the bottom surface of the accommodating groove contacts the curved surface of the elastic sheet.

[0012] According to a further technical solution of the present invention, the ends of two adjacent arc-shaped sealing casings in the annular brush sealing structure are staggered and butt-jointed along the axial direction and fixed by screws to form an annular casing; the ends of adjacent arc-shaped sealing blocks in the annular brush sealing structure are staggered and butt-jointed.

[0013] According to a further technical solution of the present invention, the axial limiting assembly includes: a limiting ring assembly, which is arranged on the axial side surface of the arc-shaped sealing casing and the arc-shaped brush fixing block.

[0014] A further technical solution of the present invention is that the limiting ring assembly includes: two axial fixing rings, which are arranged on the axial side of the annular brush sealing structure, wherein the axial fixing rings are connected to the axial side surfaces corresponding to the arc-shaped sealing casing and the arc-shaped brush fixing block, and the axial surfaces of the axial fixing rings and the arc-shaped sealing block are in contact.

[0015] The beneficial effects of the present invention are: 1. By dividing the annular sealing structure into multiple arc-shaped sealing structures and providing a guide limit assembly and an elastic support assembly between the arc-shaped sealing casing and the arc-shaped sealing block of the arc-shaped sealing structure, when the rotor undergoes radial runout or temperature changes, the arc-shaped sealing block can adaptively move in the guide limit assembly to adjust the sealing gap between the brush bundle and the rotor, thereby improving the sealing performance and brush life.

[0016] 2. By dividing the arc-shaped sealing structure into multiple sections, the arc-shaped brush fixing blocks are arranged alternately, that is, the brush bundles are arranged alternately to achieve omnidirectional jumping, thereby providing sealing ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic structural diagram of a radially adjustable brush seal structure with a thermal response adjustment function according to the present invention; Figure 2 for Figure 1 A schematic diagram of the structure after removing the first axial fixing ring and the second axial fixing ring; Figure 3 for Figure 2 Structural schematic diagram of a single arc-shaped sealing structure; Figure 4 for Figure 2 Schematic diagram of the connection between two adjacent arc-shaped sealing structures; Figure 5 for Figure 1 Schematic diagram of the connection between two adjacent arc-shaped sealing structures; Figure 6 for Figure 5 A top view of Figure 7Schematic diagram of the structure of the elastic sheet in an embodiment of the present invention using a composite multi-temperature zone response spring sheet.

[0019] In the figure: 1. Arc-shaped sealing structure; 2. Arc-shaped sealing casing; 3. Tension spring; 4. Fixing screw; 5. Elastic sheet; 6. Arc-shaped sealing block; 7. Arc-shaped brush fixing block; 8. Guide column; 9. First axial fixing ring; 10. Second axial fixing ring; 21. Second limiting protrusion; 51. Guide slot; 61. Limiting column; 81. First limiting protrusion; 82. Mounting slot. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] An embodiment of a radially adjustable brush seal structure with a thermal response adjustment function of the present invention is as follows: Figure 1 and Figure 2 As shown, it includes: a plurality of arc-shaped sealing structures 1, the end faces of the plurality of arc-shaped sealing structures 1 are connected to form an annular brush-type sealing structure, wherein, as Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown, the arc-shaped sealing structure 1 includes: an arc-shaped sealing casing 2, an elastic support assembly and an axial limit assembly. The inner arc surface of the arc-shaped sealing casing 2 is slidably connected to the arc-shaped sealing block 6 through a guide limiter; the guide limiter assembly is used to limit the movement of the arc-shaped sealing block 6 in the radial direction and the position of the movement when the arc-shaped sealing block 6 is subjected to force; the elastic support assembly is used to reset the arc-shaped sealing block 6, and after resetting, the arc-shaped sealing block 6 is supported so that a first movable gap is formed between the outer arc surface of the arc-shaped sealing block 6 and the inner arc surface of the arc-shaped sealing casing 2; the inner ring of the arc-shaped sealing block 6 is provided with an arc-shaped brush fixing block 7, and the axial limiter assembly is used to limit the axial movement of the arc-shaped sealing block 6; wherein, as Figure 3 As shown, the ends of the arc-shaped sealing blocks 6 of two adjacent arc-shaped sealing structures 1 in the annular brush seal structure and the ends of the arc-shaped sealing casings 2 of two adjacent arc-shaped sealing structures 1 are staggered and connected along the axial direction, and a second movable gap is left between the end surfaces of the arc-shaped sealing blocks 6 of the two adjacent arc-shaped sealing structures 1; it should be noted that, as Figure 1 As shown, in this embodiment, the corresponding angle of the arc surface of the arc-shaped sealing block 6 is 60°, that is, the end surfaces of the six arc-shaped sealing blocks 6 are staggered and spliced ​​to form a complete annular sealing member.

[0022] For example, Figure 2 and Figure 3 As shown, in a specific embodiment, the guide limit assembly includes: two guide posts 8 and guide grooves arranged in a one-to-one correspondence, the two guide posts 8 are evenly distributed on the outer arc surface of the arc-shaped sealing block 6, and a first limit protrusion 81 is provided on the side of the free end of the guide post 8; the two guide grooves are evenly distributed on the inner arc surface of the arc-shaped sealing casing 2, and a second limit protrusion 21 is provided on the side wall of the guide groove facing the arc-shaped sealing block 6; wherein, the guide post 8 is radially slidably arranged in the corresponding guide groove, and the first limit protrusion 81 and the second limit protrusion 21 form a limit for the radial movement position of the arc-shaped sealing block 6, that is, when the rotor undergoes radial runout or temperature changes, the arc-shaped sealing block 6 is forced to move radially under the guide limit of the guide limit assembly. At this time, due to the restriction of the first limit protrusion 81 and the second limit protrusion 21, the arc-shaped sealing block 6 can only move a certain distance in the radial direction.

[0023] For example, Figure 2 As shown, in a specific embodiment, the elastic reset component includes: an elastic sheet 5 and a tension spring 3, the elastic sheet 5 is arranged on the outer arc surface of the arc-shaped sealing block 6 between every two adjacent guide columns 8, one end of the elastic sheet 5 is connected to the outer arc surface of the arc-shaped sealing block 6, and the other end of the elastic sheet 5 is in contact with the inner arc surface of the arc-shaped sealing casing 2; the tension spring 3 is arranged in the installation groove 82 opened on the guide column 8, one end of the tension spring 3 is connected to the inner bottom surface of the installation groove 82, and the other end of the tension spring 3 is connected to the groove bottom surface of the guide groove on the inner arc surface of the arc-shaped sealing casing 2; specifically, the elastic reset component includes: an elastic sheet 5 and a tension spring 3, wherein the elastic sheet 5 is arranged on the outer arc surface of the arc-shaped sealing block 6 between every two adjacent guide columns 8, one end of the elastic sheet 5 is connected to the outer arc surface of the arc-shaped sealing block 6, and the other end of the elastic sheet 5 is in contact with the inner arc surface of the arc-shaped sealing casing 2; The sheet 5 is made of shape memory alloy material, and the shape of the elastic sheet 5 is Ω-shaped, U-shaped, semi-arc-shaped, wavy or crescent-shaped with a curved surface, wherein the curved surface of the elastic sheet 5 contacts the inner curved surface of the arc-shaped sealing casing 2, and has two free ends on the side away from the curved surface of the elastic sheet 5, and one of the free ends is connected to the outer curved surface of the arc-shaped sealing block 5, and the other free end is connected to the outer curved surface of the arc-shaped sealing block 5 in a circumferential sliding manner; the inner curved surface of the arc-shaped sealing casing 2 is provided with a receiving groove for accommodating the elastic sheet 5, wherein the bottom surface of the receiving groove contacts the curved surface of the elastic sheet 5; specifically, as Figure 2As shown, in this embodiment, the shape of the elastic piece 5 is an Ω-type with a curved surface. The free end of the Ω-shaped elastic piece 5 on the side away from the arc surface is two connecting ears, one of which is fixed by a fixing screw 4 and the outer arc surface of the arc-shaped sealing block 6, and a guide slot 51 is provided on the other connecting ear, and a limit column 61 is provided on the outer arc surface of the arc-shaped sealing block 6, and the limit column 61 is slidably connected to the guide slot 51. It should be noted that the tension spring 3 is initially in a pre-tensioned state. In this embodiment, two tension springs 3 are provided on both sides of the Ω-shaped elastic piece 5 to provide a return traction force and cooperate with the Ω-shaped elastic piece 5 to achieve bidirectional adjustment of the arc-shaped sealing block 6. When the rotor undergoes radial runout or temperature changes, the arc-shaped sealing block 6 is forced to move radially under the guide limit of the guide limit assembly. The Ω-shaped elastic piece 5 is forced to deform under the limit of the guide structure composed of the guide slot 51 and the limit column 61 on its connecting ear; and in order to adapt to temperature changes under multiple working conditions, the elastic piece 5 adopts a composite multi-temperature zone response spring piece, such as Figure 7 As shown, the Ω-shaped elastic plate 5 in this embodiment is divided into three functional zones along the circumference. The central zone is made of material 1: nickel-titanium shape memory alloy. After solution and aging treatment, its phase transition temperature range is 70°C–78°C for austenite start and 78°C–85°C for austenite finish. When the ambient temperature rises to 80°C, the phase transition is completed, resulting in a small stroke and enabling fine-tuning of the preload. The side zones are made of material 2: nickel-titanium-hafnium high-temperature shape memory alloy. Its phase transition temperature range is 135°C–145°C for austenite start and 145°C–160°C for austenite finish. When the temperature rises to 150°C, the phase transition is completed, resulting in a large stroke and enabling high-temperature compensation. This composite multi-temperature-responsive spring exhibits differentiated recovery mechanical behavior in different temperature zones, enabling adaptive response and continuous adjustment to both high- and low-temperature operating conditions. That is, in this embodiment, the Ω-shaped elastic sheet 5 is in an elastic state before reaching the activation temperature. The Ω-shaped elastic sheet 5 is used to buffer the offset of the arc-shaped brush filament fixing block 7 caused by rotor vibration, thereby reducing the impact load between the brush filament bundle on the arc-shaped brush filament fixing block 7 and the rotor, and avoiding damage to the bristles of the brush filament bundle. When the temperature rises above the austenite transformation temperature of the memory alloy corresponding to the Ω-shaped elastic sheet 5, the bending amplitude of the Ω-shaped elastic sheet 5 decreases, driving the arc-shaped sealing block 6 to move radially outward under the traction of the tension spring 3; when the temperature drops to the martensite transformation temperature range of the memory alloy corresponding to the Ω-shaped elastic sheet 5, the Ω-shaped elastic sheet 5 returns to its initial arched shape and, by pressing the arc-shaped sealing block 6, returns the arc-shaped sealing block 6 to its initial sealing gap position, thus achieving closed-loop control of thermal response regulation.

[0024] For example, in a specific embodiment, the ends of two adjacent arc-shaped sealing casings 2 in the annular brush sealing structure are staggered and docked along the axial direction and fixed by screws to form an annular casing; the ends of adjacent arc-shaped sealing blocks 6 in the annular brush sealing structure are staggered and docked, and a second movable gap is left between the docking end faces of the two adjacent arc-shaped sealing blocks 6, that is, when the rotor undergoes radial runout or temperature changes, the arc-shaped sealing block 6 is forced to move radially under the guide limit of the guide limit assembly, and the second movable gap is a movable gap to ensure the radial outward movement of the two adjacent arc-shaped sealing blocks 6.

[0025] For example, in a specific embodiment, the axial limiting assembly includes: a limiting ring assembly, which is arranged on the axial side of the arc-shaped sealing casing 2 and the arc-shaped brush fixing block 7. Specifically, Figure 4 、 Figure 5 and Figure 6 As shown, the limiting ring assembly includes: two axial fixing rings, namely a first axial fixing ring 9 and a second axial fixing ring 10. The first axial fixing ring 9 is arranged on the upstream axial side of the annular brush seal structure, and the second axial fixing ring 10 is arranged on the downstream axial side of the annular brush seal structure. The axial fixing rings are connected to the corresponding axial side surfaces of the arc-shaped sealing casing 2 and the arc-shaped brush fixing block 7, and the axial fixing rings are in contact with the axial surface of the arc-shaped sealing block 6. It should be noted that the limiting ring assembly is used to integrally limit the displacement of the arc-shaped sealing block 6 in the axial direction, prevent the sealing failure of the arc-shaped sealing block 6, and reduce leakage.

[0026] 1. Working principle of radially adjustable brush seal structure: During aircraft engine operation, when the rotor experiences radial runout (e.g., due to manufacturing errors, uneven thermal expansion, or load disturbances), the rotor runout can cause localized changes in the contact gap between the brush bundle and the rotor. At this point, the Ω-shaped elastic sheet 5, located between the arcuate sealing block 6 and the arcuate sealing casing 2 on the outer arcuate surface of the arcuate brush fixing block 7 of the brush bundle, maintains good elastic properties in its low-temperature, unactivated state (i.e., low temperatures ≤ 70°C, corresponding to the alloy's martensite-to-austenite transition temperature As≈75±5°C and the complete martensite-to-austenite transition temperature Af≈80±5°C). It exhibits only good elasticity and does not undergo shape memory recovery deformation. When the temperature rises to a high-temperature activated state (e.g., temperature T ≥ 85°C, corresponding to the complete martensite-to-austenite transition temperature Af≈80±5°C), the elastic sheet undergoes shape memory recovery deformation, driving adaptive adjustment of the sealing gap. (Of course, different materials have different martensite and austenite temperatures. Specifically, the material parameters can be determined according to the actual working conditions.) The Ω-shaped elastic sheet 5 can produce a compliant response to the arc-shaped sealing block 6, that is, it can produce a compliant response to the arc-shaped brush fixing block 7 to form a type of compliant buffer mechanism. Specifically, when the brush bundle of the arc-shaped brush fixing block 7 is moved outward by the rotor, it pushes the arc-shaped sealing block 6 (or other sealing ring) to produce a small (0.1mm~0.5mm) radial displacement. At this time, the Ω-shaped elastic sheet 5 undergoes reversible deformation. The Ω-shaped elastic sheet 5 provides non-rigid support and buffering, effectively preventing the brush bundle from failing or breaking due to vibration and extrusion, thereby improving the reliability of the brush seal structure and the life of the brush. It is worth noting that the brush bundle is usually installed at a certain inclination angle (such as 40°). Therefore, in the traditional structure, when the brush seal sections are arranged symmetrically along the same axial plane, they cannot fully adapt to omnidirectional vibration. To this end, this embodiment adopts an axially staggered arrangement of the arc-shaped sealing blocks 6, so that the arc-shaped brush fixing blocks 7 on the arc-shaped sealing blocks 6 are also staggered, that is, two adjacent arc-shaped sealing blocks 6 are staggered by a certain distance in the axial direction (axial offset), but retain a partial radial overlapping area, ensuring better compliance while maintaining sealing coverage, forming a "staggered multi-zone composite sealing structure". In addition, in order to limit the axial movement of the sealing ring, this embodiment inserts the end faces of two adjacent arc-shaped sealing blocks 6, that is, Figure 3 As shown, the end face of one arc-shaped sealing block 6 is plug-in, and the end face of the other arc-shaped sealing block 6 is a plug-in block. The plug-in block is inserted into the plug-in groove to form a concave limit groove structure to prevent the arc-shaped sealing block 6 from moving axially; two axial fixing rings axially constrain the arc-shaped sealing block 6 to avoid axial misalignment and further reduce the leakage channel; two adjacent arc-shaped sealing casings 2 are assembled by screw fastening to ensure the rigidity and integrity of the overall structure.

[0027] 2. Principle of adaptive adjustment of radial clearance by thermal response mechanism: During the operation of the aero-engine, as the rotational speed of the aero-engine increases or the working condition continues to load, the temperature of the rotor surface gradually rises, and a significant radial thermal expansion effect is generated. At this time, if the sealing gap cannot be adjusted in real time, excessive contact or even interference between the brush wire and the rotor surface will be caused, which will lead to rapid wear, fracture or even failure of the brush wire, and seriously affect the sealing life and the safety of the whole machine. In view of the above problems, the Ω-shaped elastic sheet 5 made of a shape memory alloy material with a thermal response capability is arranged between the outer arc surface of each arc-shaped sealing block 6 and the inner arc surface of the corresponding arc-shaped sealing casing 2. When the temperature rises, the Ω-shaped elastic sheet 5 is activated by heat and gradually recovers to its “memory shape”, that is, the bending amplitude gradually decreases, and the whole presents a “lying down” state, the middle arch part descends and pushes the arc-shaped brush wire fixing block 7 to move radially outward. However, since the Ω-shaped elastic sheet 5 is unidirectional deformation and one end is fixed, the restoring force has directionality and limitation, therefore, two tension springs 3 are also designed between the outer arc surface of each arc-shaped sealing block 6 and the inner arc surface of the corresponding arc-shaped sealing casing 2 in the embodiment. The two tension springs 3 are in a pre-tension state in the initial state, that is, there is a certain internal tension. When the Ω-shaped elastic sheet 5 “lies down” due to temperature rise, it actively deforms to release part of the support force, at the same time, it releases space for the tension spring 3, and the tension spring 3 drives the arc-shaped brush wire fixing block 7 and the single arc-shaped sealing block 6 to move radially outward by means of its restoring force, so as to actively enlarge the gap between the brush wire bundle and the rotor surface, and effectively avoid the risk of interference and wear under high temperature working condition. After the aero-engine cools down, the temperature returns to below the normal temperature state, and the shape memory alloy material of the Ω-shaped elastic sheet 5 gradually recovers to the original deformation state, that is, it recovers from the “lying shape” to the original Ω shape, the middle arch rises upward, and applies a reverse thrust to the tension spring 3 and the arc-shaped sealing block 6. At this time, under the action of the rigid restoring force of the Ω-shaped elastic sheet 5, the arc-shaped sealing block 6 ring moves radially back to the initial fitting position, and recovers to the sealing contact state under the low temperature state.

[0028] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A radially adjustable brush seal structure with thermal response adjustment function, characterized in that: include: Multiple arc-shaped sealing structures, end surfaces of the multiple arc-shaped sealing structures are connected to form an annular brush-type sealing structure; The arc sealing structure includes: The inner arc surface of the arc-shaped sealing casing is slidably connected to the arc-shaped sealing block through a guide and limit assembly; the guide and limit assembly is used to limit the movement of the arc-shaped sealing block in the radial direction and the position of the movement when the arc-shaped sealing block is subjected to force; An elastic support assembly, which is used for resetting the arc-shaped sealing block and supports the arc-shaped sealing block after resetting so that a first movable gap is formed between the outer arc surface of the arc-shaped sealing block and the inner arc surface of the arc-shaped sealing casing; An arc-shaped brush fixing block, which is arranged on the inner ring of the arc-shaped sealing block; and an axial limiting assembly for limiting the axial movement of the arc-shaped sealing block; Among them, the ends of the arc sealing blocks of two adjacent arc sealing structures in the annular brush sealing structure and the ends of the arc sealing casings of two adjacent arc sealing structures are axially staggered and connected, and a second movable gap is left between the end faces of the arc sealing blocks of two adjacent arc sealing structures.

2. A radially adjustable brush seal structure with thermal response adjustment function according to claim 1, characterized in that: The guide limit assembly includes: A plurality of guide posts are evenly distributed on the outer arc surface of the arc-shaped sealing block, and a first limiting protrusion is provided on the side surface of the free end of the guide post; and a plurality of guide grooves, which are evenly distributed on the inner arc surface of the arc-shaped sealing casing, and a second limiting protrusion is provided on the side wall of the guide groove facing the arc-shaped sealing block; The guide column is radially slidably arranged in the corresponding guide groove, and the first limiting protrusion and the second limiting protrusion form a limit for the moving position of the arc-shaped sealing block in the radial direction.

3. The radially adjustable brush seal structure with thermal response adjustment function according to claim 2, characterized in that: The elastic reset assembly includes: An elastic sheet is provided on the outer arc surface of the arc-shaped sealing block between every two adjacent guide pillars, one end of the elastic sheet is connected to the outer arc surface of the arc-shaped sealing block, and the other end of the elastic sheet is in contact with the inner arc surface of the arc-shaped sealing casing; And a tension spring, which is arranged in a mounting groove opened on the guide column, one end of which is connected to the bottom surface of the mounting groove, and the other end of which is connected to the bottom surface of the guide groove on the inner arc surface of the arc-shaped sealing casing.

4. The radially adjustable brush seal structure with thermal response adjustment function according to claim 3, characterized in that: The elastic sheet is made of shape memory alloy material.

5. The radially adjustable brush seal structure with thermal response adjustment function according to claim 3, characterized in that: The elastic sheet is in the shape of an Ω-shaped, U-shaped, semi-arc-shaped, wavy or crescent-shaped sheet with a curved surface, wherein the curved surface of the elastic sheet contacts the inner curved surface of the arc-shaped sealing casing, and has two free ends on the side facing away from the curved surface of the elastic sheet, one of which is connected to the outer curved surface of the arc-shaped sealing block, and the other free end is connected to the outer curved surface of the arc-shaped sealing block in a circumferential sliding manner.

6. The radially adjustable brush seal structure with thermal response adjustment function according to claim 5, characterized in that: An accommodating groove for accommodating the elastic sheet is provided on the inner arc surface of the arc-shaped sealing casing, wherein the bottom surface of the accommodating groove contacts the curved surface of the elastic sheet.

7. The radially adjustable brush seal structure with thermal response adjustment function according to claim 1, characterized in that: The ends of two adjacent arc-shaped sealing casings in the annular brush seal structure are staggered and butt-jointed along the axial direction and fixed by screws to form an annular casing; the ends of adjacent arc-shaped sealing blocks in the annular brush seal structure are staggered and butt-jointed.

8. The radially adjustable brush seal structure with thermal response adjustment function according to claim 1, characterized in that: The axial limiting assembly comprises: a limiting ring assembly, which is arranged on the axial side surfaces of the arc-shaped sealing casing and the arc-shaped brush filament fixing block.

9. The radially adjustable brush seal structure with thermal response adjustment function according to claim 8, characterized in that: The limiting ring assembly includes: two axial fixing rings, which are arranged on the axial side of the annular brush seal structure, wherein the axial fixing rings are connected to the axial side surfaces corresponding to the arc-shaped sealing casing and the arc-shaped brush fixing block, and the axial surfaces of the axial fixing rings and the arc-shaped sealing block are in contact.

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