Self-adaptive compensation structure of shape memory material, sealing device and compensation method thereof

Abstract

The invention provides a self-adaptive compensation structure of a shape memory material, a sealing device and a compensation method thereof, the compensation structure is a compensation ring of a zero Poisson's ratio thin-wall annular structure, and the compensation ring is located between a sealing piece and a base; the compensation ring is made of a shape memory polymer; the compensation ring is provided with a plurality of structural layers, each structural layer is formed by annularly connecting a plurality of unit cells, each unit cell comprises a frame unit and a connecting unit, the frame units form a closed-loop inner cavity, the connecting units are used for connecting the adjacent unit cells, and each frame unit is a frame body with the hollow middle and is in the shape of four symmetrical petals. A gap allowing deformation is formed between every two adjacent unit cells; and after the compensation ring is excited, the curvature of each petal in the compensation ring unit cell is changed, so that the height of the compensation ring is changed. According to the invention, adaptive compensation can be realized.

Description

Technical Field

[0001] The present invention relates to the field of sealing structures or memory materials, and in particular to an adaptive compensation structure of a shape memory material, a sealing device and a compensation method thereof. Background Art

[0002] Compensation loops are widely used in industrial control systems. Their primary function is to compensate for various nonlinearities, uncertainties, and time-varying factors in the system, thereby improving control accuracy and stability. During industrial production, systems often experience varying degrees of performance degradation due to factors such as equipment wear and environmental changes, necessitating adjustment and optimization through compensation loops.

[0003] Compensation rings are key components in mechanical seals. Often installed together with the seal, they utilize elastic elements (such as springs and O-rings) to automatically compensate for wear on the seal end faces, thereby improving the seal's performance and extending the life of the device. Harsh operating conditions place stringent demands on compensation rings. Traditional compensation rings, due to their simple structure, often suffer from insufficient strength, inability to actively compensate, poor dynamic adjustment capabilities, and non-reusability. Therefore, developing a low-cost, simple-to-process, high-strength compensation ring capable of dynamic adaptive adjustment is crucial for the field of mechanical seals.

[0004] Traditional compensation rings are mainly made of elastic parts such as rubber, such as a radial soft end face shaft seal using an elastic compensation ring disclosed in CN220706413U. This structure has good sealing performance, but the rubber-based compensation ring has the problem of irreversible elastic attenuation. For example, a throat clamp with an elastic compensation ring disclosed in CN201720653121U solves the problems of insufficient tightness of the connection between the traditional hoop shell and the hoop band, insufficient tension resistance, etc., but the material matrix is single, the supporting structure is weak, and it is easy to deform under high pressure. There are also some that use other compensation elements to achieve compensation functions, such as a rubber ring sealed bypass pressure balancing sleeve compensator disclosed in CN104061398A. A sealing cavity is formed by a rubber ring sealing assembly, and the compression of the internal sealing cavity is used to achieve pipeline thermal deformation compensation. However, it only relies on the physical compression of the sealing filler, and no dynamic adjustment structure is designed. It cannot adaptively compensate for the expansion of the filler gap caused by long-term wear. In the field of sealing, compensation rings that can automatically compensate are often used. For example, a sealing ring assembly with automatic compensation function disclosed in CN202110820673A. When the sealing ring body is worn, the elastic compensation part will extend the sealing ring body outward to automatically compensate for the wear of the sealing ring body, thereby prolonging the sealing failure. However, there are problems of structural redundancy and response delay. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention provides an adaptive compensation structure, sealing device, and compensation method using shape memory materials. The compensation structure comprises a compensation ring with a zero Poisson's ratio, a thin-walled annular structure, and is made of a shape memory polymer. When the elastic member is severely worn and unable to seal with the locking member, a heat medium is introduced through a fluid medium to provide stimulation. Upon stimulation, the curvature of each petal in the structural layer changes, altering the height of the compensation ring to re-seal the elastic member and the locking member, thereby achieving adaptive compensation. Cooling by introducing a cold medium through the fluid medium stabilizes the compensation ring's shape after compensation.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] An adaptive compensation structure of a shape memory material, wherein the compensation structure is a compensation ring with a zero Poisson's ratio thin-walled ring structure, and the compensation ring is located between a seal and a base; the material of the compensation ring is a shape memory polymer;

[0008] The compensation ring has a multi-layer structural layer, each structural layer is composed of multiple unit cells connected in a ring shape, the unit cell includes a frame unit and a connecting unit, the frame unit forms a closed-loop inner cavity, the connecting unit is used to connect adjacent unit cells, the frame unit is a frame with a hollow middle, and is in the shape of four symmetrical petals; there is a gap between adjacent unit cells that allows deformation; when the compensation ring is excited, the curvature of each petal in the compensation ring unit cell changes, thereby changing the height of the compensation ring.

[0009] Furthermore, the frame unit is a thin-walled curved surface, and the frame units between different cells are connected by connecting units. The connecting units are placed at the four vertices of the frame unit. The four petals of the frame unit have the same curvature. After the compensation ring is excited, the compression deformation of the frame unit is not less than 30%.

[0010] Furthermore, the upper and lower surfaces of the compensation ring are provided with thin-walled layers, and the thickness of the thin-walled layers is 1-2 mm.

[0011] A sealing device comprising the adaptive compensation structure of the shape memory material, a locking member, an elastic member and a base;

[0012] The elastic member is installed on the base; the locking member compresses the elastic member so that the elastic member and the locking member are sealed and fitted together; a compensation ring is installed between the elastic member and the base; a through hole for circulating fluid medium is provided in the middle of the base; the compensation ring is stimulated by the change of the fluid medium temperature, causing the compensation ring to deform.

[0013] Furthermore, when the fluid medium is input into the hot medium to stimulate the compensation ring, the hot medium stimulates the compensation ring to heat up and soften and triggers the shape memory effect, causing the curvature of each petal in the compensation ring to change, thereby changing the height of the compensation ring; when the fluid medium is input into the cold medium to stimulate the compensation ring, the cold medium stimulates the compensation ring to change from a rubber state to a glass state, fixing the shape memory state of the compensation ring.

[0014] Furthermore, the compensation ring is subjected to external force and cooled in a rubber state, and then changes into a compressed state; the compensation ring in the compressed state is mounted on the base.

[0015] A compensation method for a sealing device comprises the following steps:

[0016] The compensation ring is heated to a glass transition temperature to soften the material of the compensation ring, and a longitudinal external force is applied to the compensation ring to change the curvature of the petals of the frame unit of each unit cell of the compensation ring, thereby deforming the compensation ring from an initial height h1 to a compressed height h2; while maintaining the compressed height h2 unchanged, the temperature is lowered until the material hardens, and the compressed compensation ring is installed in the base;

[0017] When the seal between the elastic part and the locking part fails, the fluid medium inputs a hot medium to provide excitation, and the compensation ring material softens and becomes rubbery through heat conduction heating. The petal curvature of the frame unit changes, and the compensation ring changes from the compression height h2 to the compensation height h3, so that the locking part and the elastic part contact and seal. The fluid medium inputs a cold medium, causing the compensation ring to change from the rubber state to the glass state, fixing the shape memory state; the compensation height h3 is between h2 and h1.

[0018] The beneficial effects of the present invention are:

[0019] 1. The adaptive compensation structure of the shape memory material described in the present invention comprises a compensation ring having a multi-layer structural layer, each structural layer being formed by a plurality of unit cells connected in a ring shape, wherein the unit cells include a frame unit and a connection unit, the frame unit forming a closed-loop inner cavity, the connection unit being used to connect adjacent unit cells, the frame unit being a frame with a hollow center, and being in the shape of four symmetrical petals; gaps exist between adjacent unit cells that allow deformation; when the compensation ring is stimulated, the curvature of each petal in the compensation ring unit cell changes, thereby changing the height of the compensation ring; the compensation ring of the present invention achieves low-cost and rapid iteration.

[0020] 2. The sealing device described in the present invention uses a fluid medium to trigger the shape memory effect to achieve compensation, can actively respond to stimuli, and has dynamic adaptive compensation capabilities, breaking through the passive limitations of traditional static structures.

[0021] 3. The sealing device of the present invention utilizes temperature changes to stimulate the deformation of the compensation ring, has a wide range of applications, and avoids installation problems such as size mismatch. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the sealing device of the present invention.

[0024] Figure 2 This is a three-dimensional diagram of the compensation ring described in the present invention.

[0025] Figure 3 Schematic diagram of the structure of the compensation ring unit cell described in the present invention.

[0026] Figure 4 This is a simulation diagram of the compensation ring before and after compression described in the present invention.

[0027] Figure 5 This is a compensation flow chart of the compensation loop of the present invention;

[0028] Figure 6 Schematic diagram of the valve seat sealing structure.

[0029] In the picture:

[0030] 1-fluid medium; 2-locking part; 3-elastic part; 4-compensating ring; 5-base; 6-thin-wall layer; 7-structural layer; 8-frame unit; 9-connecting unit; 10-closed-loop inner cavity. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0034] like Figure 2 、 Figure 3 and Figure 4 As shown, the adaptive compensation structure of the shape memory material described in the present invention is a compensation ring 4 with a zero Poisson's ratio thin-walled annular structure, and the compensation ring 4 is located between the seal and the base; the material of the compensation ring 4 is a shape memory polymer; the matrix material of the compensation ring 4 is a shape memory polymer, including polyurethane acrylate PUA, isobornyl acrylate IBOA and 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester TPO-L, with mass fractions of 55wt%, 42wt% and 3wt% respectively, which are synthesized and then the compensation ring 4 is printed by stereolithography, that is, the compensation ring 4 is a thermally responsive 4D printed component.

[0035] like Figure 3 and Figure 4As shown, the compensation ring 4 has a multi-layer structure 7, each of which is formed by a plurality of unit cells connected in a ring shape. The unit cells include frame units 8 and connecting units 9. The frame units 8 form a closed-loop inner cavity 10, and the connecting units 9 are used to connect adjacent unit cells. The frame units 8 are hollowed-out frames shaped like four symmetrical petals. There are gaps between adjacent unit cells that allow for deformation. When the compensation ring 4 is excited, the curvature of each petal in the unit cells of the compensation ring 4 changes, thereby changing the height of the compensation ring 4. The compensation ring 4 has thin-walled layers 6 on the upper and lower surfaces, with a thickness of 1-2 mm.

[0036] The frame unit 8 is a thin-walled curved surface. Different unit cells of the frame unit 8 are connected by connecting units 9. The connecting units 9 are placed at the four vertices of the frame unit 8. The four petals of the frame unit 8 have the same curvature. After the compensation ring 4 is excited, the compression deformation of the frame unit 8 is not less than 30%.

[0037] Example 1

[0038] like Figure 1 and Figure 6 As shown, the sealing device of the present invention comprises the adaptive compensation structure of the shape memory material, a locking member 2, an elastic member 3, and a base 5. The base 5 has a groove for accommodating the elastic member 3 and the compensation ring 4, with the compensation ring 4 positioned inside. The elastic member 3 is made of PTFE (polytetrafluoroethylene) and has excellent elasticity. The locking member 2 is mounted on the outside of the elastic member 3. The locking member 2 is used to compress the elastic member 3, ensuring a sealing fit between the elastic member 3 and the locking member 2, forming an effective seal. The elastic member 3 and the base 5 are annular structures, and the locking member 2 has structural shapes including, but not limited to, annular and spherical shapes. A central through-hole is provided for the circulation of a fluid medium 1. In this embodiment, the base 5 is a ball valve seat, and the locking member 2 is a sphere with a through-hole. Under the action of a preload force, the elastic member 3 is compressed, ensuring a sealing fit between the elastic member 3 and the locking member 2, forming an effective seal. The elastic member 3 is made of polytetrafluoroethylene, which has excellent elasticity. The contact surface is configured as a curved surface, which ensures a better sealing fit with the locking member, preventing leakage of the fluid medium.

[0039] The compensation ring is a thin-walled annular structure with a zero Poisson's ratio. The outer diameter, inner diameter and height of the compensation ring are 200mm, 165mm and 65mm respectively. It is composed of a structural layer 7 and a thin-walled layer 6. The thickness of the thin-walled layer 6 is 1-2mm. The structural layer 7 is formed by a plurality of unit cells connected in a ring shape. The unit cell includes a frame unit 8 and a connecting unit 9. The frame unit 8 forms a closed-loop inner cavity 10. The frame unit 8 is a frame with a hollow middle and is in the shape of four symmetrical petals. The frame units 8 between different unit cells are connected by connecting units 9, and the connecting units 9 are placed at the four vertices of the frame unit 8. The four petals of the frame unit 8 have the same curvature. When the compression deformation of the compensation ring 4 is within 40%, as shown in FIG. Figure 4 As shown, the deformation of the frame unit 8 presents a zero Poisson's ratio, and the compensation ring as a whole presents a zero Poisson's ratio structure.

[0040] When the fluid 1 is fed into the compensation ring 4 as a hot medium, it heats up and softens, triggering a shape memory effect. This causes the curvature of each petal in the compensation ring 4 to change, thereby altering the ring's height. When the fluid 1 is fed into the compensation ring 4 as a cold medium, the cold medium stimulates the ring 4 to transition from a rubbery state to a glassy state, fixing the ring's shape memory state. After cooling under external force in the rubbery state, the compensation ring 4 transitions to a compressed state. The compressed compensation ring 4 is then mounted on the base 5.

[0041] The base material of the compensation ring 4 is a shape memory polymer, including polyurethane acrylate PUA, isobornyl acrylate IBOA and 2,4,6-trimethylbenzoylphenylphosphonate TPO-L, with mass fractions of 55wt%, 42wt% and 3wt% respectively. The compensation ring 4 is synthesized and then printed by stereolithography.

[0042] like Figure 5 As shown, the compensation method of the sealing device of the present invention specifically includes the following steps:

[0043] Before installation, the compensation ring 4 is heated in a water bath at 50-70°C to soften the material and transform it from a glassy state to a rubbery state. The compensation ring 4 is compressed by mechanical loading to deform it from an initial height h1 to a compressed height h2. Mechanical loading external force is used to keep the compressed height h2 unchanged. The material is cooled by cold water until it hardens and transforms from a rubbery state to a glassy state, and then assembled into the compensation system.

[0044] During use, the ball valve rotates frequently to control the opening and closing of the valve, causing friction and wear between the elastic member 3 and the ball of the locking member 2. When the elastic member 3 wears to a certain extent, the seal fails and leakage occurs. At this time, the fluid medium 1 is introduced into the compensation ring 4 at 80-90°C. The fluid medium 1 heats the compensation ring 4 through heat conduction, transforming it from a glassy state to a rubbery state. This triggers the shape memory effect, causing the petal curvature to change. The compensation ring 4 changes from a compressed height h2 to a compensation height h3, and the locking member 2 ball and the elastic member 3 re-engage and seal. At this time, the fluid medium 1 is replaced by a room temperature liquid, which cools the compensation ring 4 through heat conduction, transforming it from a rubbery state to a glassy state, fixing its shape. The compensation height h3 is between h2 and h1, indicating adaptive performance.

[0045] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0046] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An adaptive compensation structure of shape memory material, characterized in that: The compensation structure is a compensation ring (4) with a zero Poisson's ratio thin-walled annular structure, and the compensation ring (4) is located between the sealing element and the base; the material of the compensation ring (4) is a shape memory polymer; The compensation ring (4) has a multi-layer structural layer (7), each structural layer (7) is formed by connecting a plurality of unit cells in a ring shape, the unit cells include a frame unit (8) and a connection unit (9), the frame unit (8) forms a closed-loop inner cavity (10), the connection unit (9) is used to connect adjacent unit cells, the frame unit (8) is a frame body with a hollow middle, and is in the shape of four symmetrical petals; there is a gap between adjacent unit cells that allows deformation; when the compensation ring (4) is excited, the curvature of each petal in the unit cell of the compensation ring (4) changes, thereby changing the height of the compensation ring (4).

2. The adaptive compensation structure of shape memory material according to claim 1, characterized in that: The frame unit (8) is a thin-walled curved surface. Different unit cells of the frame unit (8) are connected by connecting units (9). The connecting units (9) are placed at the four vertices of the frame unit (8). The four petals of the frame unit (8) have the same curvature. After the compensation ring (4) is excited, the compression deformation of the frame unit (8) is not less than 30%.

3. The adaptive compensation structure of shape memory material according to claim 1, characterized in that: The upper and lower surfaces of the compensation ring (4) are provided with thin-walled layers (6), and the thickness of the thin-walled layer (6) is 1-2 mm.

4. A sealing device, characterized in that: An adaptive compensation structure comprising the shape memory material according to any one of claims 1 to 3, a locking member (2), an elastic member (3) and a base (5); The elastic member (3) is mounted on a base (5); the locking member (2) compresses the elastic member (3) so that the elastic member (3) and the locking member (2) are sealed and fitted together; a compensation ring (4) is mounted between the elastic member (3) and the base; a through hole for circulating a fluid medium (1) is provided in the middle of the base (5); the compensation ring (4) is excited by changes in the temperature of the fluid medium (1), causing the compensation ring (4) to deform.

5. The sealing device according to claim 4, characterized in that When the fluid medium (1) is input into the heat medium to stimulate the compensation ring (4), the heat medium stimulates the compensation ring (4) to heat up and soften, and triggers the shape memory effect, so that the curvature of each petal in the compensation ring (4) changes, thereby changing the height of the compensation ring; When the fluid medium (1) is input into the cold medium excitation compensation ring (4), the cold medium stimulates the compensation ring (4) to change from a rubber state to a glass state, thereby fixing the shape memory state of the compensation ring.

6. The sealing device according to claim 5, characterized in that The compensation ring (4) is subjected to external force and cooled in a rubber state, and then changes into a compressed state; the compensation ring (4) in the compressed state is mounted on a base (5).

7. A compensation method for a sealing device according to any one of claims 4 to 6, characterized in that: The steps include: The compensation ring (4) is heated to a glass transition temperature to soften the material of the compensation ring (4), and a longitudinal external force is applied to the compensation ring (4) to change the curvature of the petals of the frame unit (8) of each unit cell of the compensation ring (4), thereby deforming the compensation ring (4) from an initial height h1 to a compressed height h2; the compressed height h2 is kept constant, the temperature is lowered until the material hardens, and the compressed compensation ring (4) is installed in the base (5); When the seal between the elastic member (3) and the locking member (2) fails, the fluid medium (1) inputs a hot medium to provide excitation, and the material of the compensation ring (4) softens and becomes rubbery through heat conduction heating, the petal curvature of the frame unit (8) changes, and the compensation ring (4) changes from a compression height h2 to a compensation height h3, so that the locking member (2) and the elastic member (3) are in contact and sealed; the fluid medium (1) inputs a cold medium, so that the compensation ring (4) changes from a rubbery state to a glassy state, fixing the shape memory state; the compensation height h3 is between h2 and h1.

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