A main beam structure of a wind turbine blade

Abstract

The present invention discloses a main beam structure of a wind turbine blade, which includes a blade body and a plurality of vibration isolation unit bodies. The inside of the blade body has a cavity for increasing strength and installing other components. A plurality of vibration isolation unit bodies are arranged inside the cavity. The vibration isolation unit bodies extend along the length direction of the blade body, and the plurality of vibration isolation unit bodies are arranged in a transverse and vertical array along the cross-section of the blade body. Adjacent two vibration isolation unit bodies are connected to each other to form an I-shaped main beam, and both ends of the I-shaped main beam are respectively connected to both sides of the cavity; through the I-shaped main beam formed by the plurality of vibration isolation unit bodies and the I-shaped main beam extending along the length direction of the blade body, not only can the supporting effect on the blade body be increased, but also under the action of the vibration isolation unit bodies, a phononic crystal band gap can be formed to play a vibration isolation role, avoiding the transmission of low-frequency vibration at the tip of the blade body to the root of the blade body and causing damage to the blade body.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blades, and particularly to a main beam structure of a wind turbine blade. Background Art

[0002] A wind turbine, also often referred to as a wind power generator, is a device that converts wind energy into electrical energy; the wind turbine blade is the core component for the wind turbine to convert wind energy into mechanical energy, and the reliability of the wind turbine blade plays a crucial role in the safe operation of the wind turbine. Due to the erratic changes in wind speed and direction, the working environment of the wind turbine is very complex. The wind wheel is long-term exposed to a series of complex loads such as aerodynamic loads, centrifugal loads, and gravitational loads. The tower has its own natural frequency, and there will also be vibration frequencies during the operation of the generator. If the frequency of the blade resonates with any of these frequencies, it will cause fatigue damage. One of the main factors for blade failure is blade resonance. This phenomenon will exacerbate the fatigue of the blade material, reduce its effective service life, and even directly cause blade damage and fracture in severe cases. The loads on the fuselage or blade will be amplified due to the resonance phenomenon, and the fuselage or blade will experience severe jitter, affecting its power generation efficiency and even causing damage in severe cases.

[0003] During the operation of the wind turbine, the tip of the wind turbine blade will generate low-frequency vibrations under the action of external wind forces. The low-frequency vibrations will be transmitted to the root of the wind turbine blade, and the existing wind turbine blades in the prior art cannot effectively block the transmission of the low-frequency vibrations at the tip of the wind turbine blade, thus reducing the durability and stability of the wind turbine blade.

[0004] In view of this, the prior art still needs to be improved and developed. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a main beam structure of a wind turbine blade, aiming to solve the problem that the existing wind turbine blades cannot effectively block the transmission of low-frequency vibrations generated at the tip of the wind turbine blade, thereby reducing the durability and stability of the wind turbine blade.

[0006] The technical solution adopted by the present invention to solve the technical problems is as follows:

[0007] A main beam structure of a wind turbine blade, comprising:

[0008] A blade body, which has a cavity inside;

[0009] A plurality of vibration isolation unit bodies, arranged in the cavity; each of the vibration isolation unit bodies extends along the length direction of the blade body, and the plurality of vibration isolation unit bodies are arranged in a transverse and vertical array along the cross-section of the blade body. Adjacent two of the vibration isolation unit bodies are connected to each other to form an I-shaped main beam, and both ends of the I-shaped main beam are respectively connected to both sides of the cavity.

[0010] According to the above technical means, the I-shaped main beam formed by multiple vibration isolation unit bodies, and the I-shaped main beam extending along the length direction of the blade body can not only increase the supporting effect on the blade body, but also play a vibration isolation role under the action of the vibration isolation unit bodies, avoiding the transmission of low-frequency vibration at the tip of the blade body to the root of the blade body and causing damage to the blade body.

[0011] Furthermore, the vibration isolation unit body includes:

[0012] Two U-shaped plates; the two side walls of the U-shaped plate are arranged obliquely, and the two ends of the two U-shaped plates correspond to each other and are connected to each other to enclose a receiving cavity with an opening, and recessed parts are formed on both sides of the vibration isolation unit body;

[0013] Two connecting plates are respectively arranged at the two connection parts of the two U-shaped plates.

[0014] By the above technical means, by arranging the two U-shaped plates opposite to each other and connecting them to each other, a structure with a Poisson's ratio can be formed, and recessed parts are formed at both ends thereof to facilitate the contraction and expansion of the vibration isolation unit body. At the same time, through the connecting plates, two adjacent vibration isolation unit bodies in the transverse direction can be connected.

[0015] Furthermore, the two U-shaped plates corresponding to two vertically adjacent vibration isolation unit bodies are connected to each other, and the two connecting plates corresponding to two horizontally adjacent vibration isolation unit bodies are connected to each other.

[0016] By the above technical means, by connecting the two U-shaped plates corresponding to two vertically adjacent vibration isolation unit bodies to each other, and connecting the connecting plates corresponding to two horizontally adjacent vibration isolation unit bodies to each other, an I-shaped main beam can be formed for convenient installation.

[0017] Furthermore, a degradable thermosetting material is filled in the receiving cavity of the vibration isolation unit body and the gaps between adjacent multiple vibration isolation unit bodies.

[0018] According to the above technical means, through the degradable thermosetting material, not only can the contact area and friction force between components be increased to make their connection more firm, reducing the loosening and displacement during use due to vibration or external force, but also the risk of structural damage caused by excessive local stress can be reduced, and the service life of the structure can be prolonged, just like adding a "protective layer" for buffering and sharing stress at the gap.

[0019] Furthermore, the degradable thermosetting material is any one of epoxy resin, phenolic resin, epoxy acrylate and polyester resin.

[0020] According to the above technical means, a variety of degradable thermosetting materials are provided for selection to facilitate selection for different usage scenarios.

[0021] Further, mounting holes are penetrated through the blade body. Two ends of the I-shaped main beam are respectively located in the two mounting holes. The side wall of the I-shaped main beam is connected to the side wall of the mounting hole. A skin is arranged on the outer side of the blade body to block the mounting holes.

[0022] According to the above technical means, by arranging the mounting holes, it is convenient for the installation and fixation of the I-shaped main beam, and at the same time, the I-shaped main beam is prevented from shifting relative to the blade body; meanwhile, the skin is arranged to protect the I-shaped main beam.

[0023] Further, both the top and the bottom of the I-shaped main beam are arc-shaped surfaces.

[0024] According to the above technical means, by setting both the top and the bottom of the I-shaped main beam as arc-shaped surfaces, it is convenient to cooperate with the outer surface of the blade body.

[0025] Further, grooves are arranged on the inner top wall and the inner bottom wall of the cavity. Two ends of the I-shaped main beam are respectively arranged in the two grooves. Two ends of the I-shaped main beam are respectively connected to the side wall of the cavity.

[0026] According to the above technical means, the present application provides another installation method. By opening grooves on the inner top wall and the inner bottom wall of the cavity and arranging the I-shaped main beam in the two grooves, not only the integrity of the windward side and the leeward side of the blade body can be ensured, but also the I-shaped main beam can be effectively limited.

[0027] Further, the material of the vibration isolation unit body is any one of renewable materials, natural degradable materials, fiber-reinforced resin composite materials, and 3D printing materials.

[0028] According to the above technical means, the present application provides a variety of materials for the vibration isolation unit body to be selected to meet the material selection of the vibration isolation unit body under different conditions.

[0029] Further, two I-shaped main beams are arranged inside the cavity.

[0030] According to the above technical means, by arranging two parallel I-shaped main beams in the cavity, the blocking effect of the blade body on low-frequency vibration can be effectively improved, and at the same time, the stability of the blade body can also be improved.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] In the present invention, the interior of the blade body has a cavity for increasing strength and installing other components. A plurality of vibration isolation unit bodies are arranged inside the cavity. The vibration isolation unit bodies extend along the length direction of the blade body to increase the contact area between the vibration isolation unit bodies and the inner wall of the cavity, thereby improving the supporting force. The plurality of vibration isolation unit bodies are arranged in a transverse and vertical array along the cross-section of the blade body. Adjacent two vibration isolation unit bodies are connected to each other to form an I-shaped main beam. The two ends of the I-shaped main beam are respectively connected to both sides of the cavity. The structure of the I-shaped main beam can form a phononic crystal band gap, which has an isolation effect on the low-frequency vibration generated at the tip of the blade body and blocks its transmission to the root of the blade body. Through the I-shaped main beam formed by a plurality of vibration isolation unit bodies and the extension of the I-shaped main beam along the length direction of the blade body, not only can the supporting effect on the blade body be increased, but also under the action of the vibration isolation unit bodies, a vibration isolation effect can be achieved, avoiding the transmission of the low-frequency vibration at the tip of the blade body to the root of the blade body and causing damage to the blade body. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0034] Figure 2 It is a schematic diagram of the structure of the vibration isolation unit body of the present invention.

[0035] Figure 3 It is a schematic diagram of the double I-shaped main beam structure of the present invention.

[0036] Figure 4 It is a schematic diagram of the structure of the I-shaped main beam and the cavity of the present invention.

[0037] The numeral markings in the figure are represented as: 1, blade body; 11, cavity; 2, vibration isolation unit body; 21, I-shaped main beam; 22, U-shaped plate; 23, connecting plate; 24, accommodation cavity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to make the objectives, technical solutions and effects of the present invention clearer and more definite, the following further describes the present invention in detail with reference to the accompanying drawings and by way of examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 should not be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0040] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Modal analysis is a commonly used method for studying the dynamic characteristics of modern structures and is also an important application of system identification methods in the field of engineering vibration. According to the research results of the natural vibration characteristics, resonance caused by the same external excitation and natural vibration frequency can be effectively avoided, and the damage of mechanical structures can be prevented.

[0042] Currently, many systematic studies have been conducted on the natural frequencies and modal vibration modes of wind turbines at home and abroad; through modal analysis, the weak links and vibration characteristics of the structure can be understood, providing a basis for the structural optimization of wind turbines, such as adjusting the shape, thickness, material, etc. of the blades, or improving the strength and stiffness of the structure, or reducing the structural weight; however, the above-mentioned modal analysis methods only improve the shape, thickness, or material of the blades, and very few structures for increasing reinforcement and anti-vibration are added to the blade structure. With long-term use, especially in complex environments, the wind turbine blades are very likely to resonate with the external environment. Although the structure of the blades has been improved, after long-term use, it will still cause certain damage to the blades.

[0043] In view of the deficiencies of the prior art, the present embodiment provides a main beam structure of a wind turbine blade, which is specifically as follows:

[0044] As shown in the atta Figure 1 and attaFigure 2 As shown in the figure, a main beam structure of a wind turbine blade includes a blade body 1 and a plurality of vibration isolation unit bodies 2. A cavity 11 is provided inside the blade body 1. The setting of the cavity 11 can not only increase the strength of the blade body 1, but also be used to place electronic components, such as some circuits of the lightning protection system, sensors for monitoring the state (such as strain, temperature, etc.) of the blade body 1, etc. At the same time, it is also convenient for maintaining the blade body 1; a plurality of vibration isolation unit bodies 2 are provided inside the cavity 11. Each vibration isolation unit body 2 extends along the length direction of the blade body 1 and is in a strip shape. The plurality of vibration isolation unit bodies 2 are arranged in a transverse and vertical array along the cross section of the blade body 1, and adjacent two vibration isolation unit bodies 2 are connected to each other to form an I-shaped main beam 21; the vertical two ends of the I-shaped main beam 21 are respectively connected to the upper and lower sides of the cavity 11. The I-shaped main beam 21 formed by the plurality of vibration isolation unit bodies 2 and the I-shaped main beam 21 extending along the length direction of the blade body 1 can not only increase the supporting effect on the blade body 1, but also play a vibration isolation role under the action of the vibration isolation unit bodies 2, avoiding the transmission of low-frequency vibration at the tip of the blade body 1 to the root of the blade body 1 and causing damage to the blade body 1.

[0045] The vibration isolation unit body 2 also has the property of negative Poisson's ratio. Through the periodic arrangement of the vibration isolation unit bodies 2 with negative Poisson's ratio effect, a phononic crystal band gap is formed, which has an isolation effect on the low-frequency vibration generated at the tip of the blade body 1 and blocks its transmission to the root of the blade body 1 (the connection between the blade body 1 and the wind turbine rotating shaft), forming vibration isolation protection for the structure of the blade body 1 and improving the durability and stability of the structure of the blade body 1. Compared with the prior art, the present invention has the ability to improve the anti-vibration and anti-damage capabilities of the main stress part of the blade body 1.

[0046] The negative Poisson's ratio structure has received extensive attention due to its many novel and unique properties, such as tensile piezoresistive properties, porosity / permeability variability with strain, etc.; at the same time, compared with ordinary structures, many mechanical properties of the negative Poisson's ratio structure have been enhanced. Negative Poisson's ratio is a property independent of scale. Whether at the macroscopic, microscopic or mesoscopic level, the negative Poisson's ratio effect can be realized, and it has excellent anti-fatigue, vibration reduction and noise reduction, energy absorption and other properties. It is precisely due to the excellent properties of the negative Poisson's ratio structure and the scale it covers that it has a wide range of applications.

[0047] In the present application, the vibration isolation unit 2 and the combined I-shaped main beam 21 enable the large-scale power generation wind turbine structure to have vibration isolation and anti-fatigue functions. Through the arrangement and variation of the vibration isolation unit 2 in space, the elastic modulus, Poisson's ratio, density, etc. of the structure change in spatial position. The size of the overall structure of the blade body 1 can be calculated according to the buffer and shock absorption requirements, so as to obtain the size, arrangement mode of the vibration isolation unit 2 and the number of vibration isolation units 2 required for each row and column, effectively improving the resonance phenomenon of the existing blade body 1.

[0048] In one embodiment of the present application, as shown in the attached Figure 2 figure, the vibration isolation unit 2 includes two U-shaped plates 22 and two connecting plates 23. The two side walls of the U-shaped plate 22 are arranged obliquely, that is, the overall U-shaped plate 22 is arranged in an isosceles trapezoid shape. One side of the U-shaped plate 22 has an opening. The openings of the two U-shaped plates 22 correspond to each other, and the two ends of the two U-shaped plates 22 correspond to each other and are connected to enclose an accommodating cavity 24 with an opening. Since the two side walls of the U-shaped plate 22 are inclined, recessed parts are formed on both sides of the vibration isolation unit 2. Through the action of the recessed parts, the vibration isolation unit 2 can have the characteristics of contraction and expansion; and a connecting plate 23 is arranged at the connection of the two U-shaped plates 22, and the connecting plate 23 is used to connect with adjacent vibration isolation units 2 to improve the stability of the I-shaped main beam 21.

[0049] Through the combined setting of the two U-shaped plates 22, the vibration isolation unit 2 can have a negative Poisson's ratio effect. By connecting adjacent two vibration isolation units 2 through the bottom plate of the U-shaped plate 22 and through the connecting plate 23, a phononic crystal band gap is formed to isolate the low-frequency vibration generated at the tip of the blade body 1 and block its transmission to the root of the blade body 1, forming vibration isolation protection for the structure of the blade body 1 and improving the durability and stability of the structure of the blade body 1.

[0050] As shown in the attached Figure 4 figure, wherein both the connecting plate 23 and the U-shaped plate 22 extend along the length direction of the blade body 1. Two laterally adjacent vibration isolation units 2 are connected by two corresponding connecting plates 23, so that the two laterally adjacent vibration isolation units 2 form a whole, and the U-shaped plates 22 of the two laterally adjacent vibration isolation units 2 are in an interval state to provide a relatively deformable space; through the action of the connecting plate 23, when one of the vibration isolation units 2 is subjected to a force, the force can be transmitted to the adjacent vibration isolation unit 2 through the connecting plate 23 to achieve the function of dispersing and reducing the force.

[0051] In this embodiment, the two U-shaped plates 22 corresponding to two vertically adjacent vibration isolation unit bodies 2 are connected to each other, and the opposite sides of the corresponding two U-shaped plates 22 are both flat surfaces, and they can be connected by welding, sintering or bonding, so as to improve the vertical stability of the I-shaped main beam 21, and at the same time ensure that the acting force can be dispersed vertically; the two connecting plates 23 corresponding to two horizontally adjacent vibration isolation unit bodies 2 are connected to each other, so that the vibration isolation unit bodies 2 in the horizontal direction are connected, providing the stability of the I-shaped main beam 21 in its horizontal direction.

[0052] In this embodiment, the vertical direction of the I-shaped main beam 21 is the up-and-down direction of the cross-section of the blade body 1, and the horizontal direction of the I-shaped main beam 21 is the left-and-right direction of the cross-section of the blade body 1.

[0053] In this embodiment, the accommodating cavity 24 of the vibration isolation unit body 2 and the gaps between adjacent multiple vibration isolation unit bodies 2 are filled with a degradable thermosetting material; in the I-shaped main beam 21 composed of multiple vibration isolation unit bodies 2, the degradable thermosetting material filled in the internal gaps is equivalent to a kind of "glue" or "filler", which can better connect the components together. After the material is cured, it can fill the gap space, increase the contact area and friction between the components, make their connection more firm, and reduce the situation of loosening and displacement during use due to vibration or external force; when the I-shaped main beam 21 is subjected to external force, the gap is often the weak link where stress concentration occurs. After filling with the degradable thermosetting material, it can participate in the process of force transmission and dispersion, disperse the stress originally concentrated at the edge of the gap to a larger filling material area and the structural components connected thereto, reduce the risk of structural damage caused by excessive local stress, and extend the service life of the structure, just like adding a "protective layer" for buffering and sharing stress at the gap.

[0054] In this embodiment, the degradable thermosetting materials can be arranged at intervals, that is, there is an accommodating cavity 24 of a vibration isolation unit body 2 or a gap formed by multiple vibration isolation unit bodies 2 between two vertically adjacent degradable thermosetting materials. By the way of interval arrangement, the transmission of low-frequency vibration can be further blocked.

[0055] Furthermore, the degradable thermosetting material can also be filled on the outer surface of the I-shaped main beam 21 through a mold to facilitate the sealing effect after the connection between the I-shaped main beam 21 and the blade body 1.

[0056] Furthermore, the degradable thermosetting material is any one of epoxy resin, phenolic resin, epoxy acrylate and polyester resin.

[0057] In this embodiment, the degradable thermosetting material can also be replaced with a degradable thermoplastic material for convenient recycling. The degradable thermoplastic material can be PBS (polybutylene succinate) or plastic, etc.

[0058] In this embodiment, mounting holes are provided through the blade body 1, and both ends of the I-shaped main beam 21 are respectively located in the two mounting holes. The side wall of the I-shaped main beam 21 is connected to the side wall of the mounting hole, so that the I-shaped main beam 21 is connected to the blade body 1.

[0059] The blade body 1 includes a windward surface and a leeward surface. The external wind acts on the windward surface. Under the action of the windward surface, the blade body 1 is driven to rotate, and the mounting holes penetrate the windward surface and the leeward surface; the windward surface and the leeward surface are generally arc-shaped surfaces, and arc surfaces can also be provided at the top and bottom of the I-shaped main beam 21, so as to cooperate with the windward surface and the leeward surface, and avoid forming bumps or grooves on the windward surface and the leeward surface, so that the external wind acts on the protruding or sunken I-shaped main beam 21, resulting in the disorder of the force condition on the windward surface, uneven distribution of the external force on the blade body 1, and affecting the service life of the blade body 1.

[0060] In this embodiment, Figure 1 the vibration isolation unit body 2 in [[]] has a relatively large volume, and effective arc-shaped surfaces cannot be formed at the top and bottom of the I-shaped main beam 21. In the design, the volume of the vibration isolation unit body 2 can be reduced, so that more vibration isolation unit bodies 2 can be arranged vertically and horizontally on the I-shaped main beam 21 to form an irregular arc-shaped surface at the top and bottom of the I-shaped main beam 21, and then covered with a degradable thermosetting material to form an arc-shaped surface corresponding to the windward surface and the leeward surface.

[0061] Specifically, multiple rows of vibration isolation unit bodies 2 can be arranged horizontally at the top of the I-shaped main beam 21, and the multiple rows of vibration isolation unit bodies 2 are arranged vertically in a stacked manner. At the place where an arc-shaped surface needs to be formed, the vertical vibration isolation unit bodies 2 can be correspondingly reduced, so as to form a height difference at the top of the I-shaped main beam 21 to facilitate the formation of an arc-shaped surface; the left and right side walls of the mounting hole can be connected to the connecting plates 23 of multiple vibration isolation unit bodies 2, and the other two side walls of the mounting hole can be directly connected to the side walls of the U-shaped plates 22 of multiple vibration isolation unit bodies 2.

[0062] The mounting hole and the vibration isolation unit body 2 can be connected by welding, bonding, sintering or nesting.

[0063] Furthermore, a skin is provided on the outside of the blade body 1. The skin is used to block the mounting holes and also provides a protective effect for the I-shaped main beam 21, avoiding the direct action of the external wind on the I-shaped main beam 21 and causing a certain impact on the I-shaped main beam 21.

[0064] Through the function of the installation holes, the I-shaped main beam 21 can be embedded in the blade body 1, and then connected by means of welding, bonding, sintering or nesting; when the blade body 1 vibrates, the connection by the embedding method can ensure that the I-shaped main beam 21 does not displace relative to the blade body 1, and the I-shaped main beam 21 is stably fixed on the blade body 1, further increasing the stability between the I-shaped main beam 21 and the blade body 1.

[0065] In this embodiment, grooves may be provided on the inner top wall and the inner bottom wall of the cavity 11. The two ends of the I-shaped main beam 21 are respectively arranged in the two grooves, and the two ends of the I-shaped main beam 21 are respectively connected to the side walls of the cavity 11; the two grooves do not penetrate the side wall of the blade body 1, thus ensuring the integrity of the windward surface and the leeward surface of the blade body 1, reducing the modification of the overall structure of the blade body 1, and through the cooperation of the groove and the I-shaped main beam 21, the groove can also limit the lateral direction of the I-shaped main beam 21, so that when the blade body 1 vibrates or sways, the I-shaped main beam 21 does not displace relative to the blade body 1.

[0066] By providing grooves on the inner top wall and the inner bottom wall of the cavity 11, not only can the integrity of the windward surface and the leeward surface of the blade body 1 be ensured, but also the I-shaped main beam 21 can be effectively limited.

[0067] The two opposite sides of the two grooves are respectively abutted against the top wall and the bottom wall of the I-shaped main beam 21. At the same time, through the action of welding, bonding or sintering, the top wall and the bottom wall of the I-shaped main beam 21 are both connected to the blade body 1, further increasing the connection area between the I-shaped main beam 21 and the blade body 1 and improving the stability between the two; when the top wall and the bottom wall of the I-shaped main beam 21 are both connected to the side walls of the groove, it can also provide a supporting force for the windward surface of the blade body 1 to make up for the defect of providing a groove on the inner side of the windward surface.

[0068] In the prior art, the structure of the blade body 1 of a wind turbine is generally slightly curved or spiral, so as to facilitate the external wind to act on the windward surface of the blade body 1 and flow along a specific direction of the windward surface, thereby driving the blade body 1 to rotate. However, such a design will also cause the acting force of the external wind on the surface of the blade body 1 to incline in the spiral direction, resulting in uneven stress on the surface of the blade body 1.

[0069] In the present application, the I-shaped main beam 21 can be arranged in a spiral shape along the length direction of the blade body 1, and the spiral direction can be opposite to the spiral direction of the blade body 1. By the spirally arranged I-shaped main beam 21 abutting against the inner wall of the cavity 11, the acting force of the external wind can be applied to the I-shaped main beam 21, and then dispersed and transmitted by the I-shaped main beam 21 to the back side of the blade body 1, reducing the direct acting force of the external wind on the windward side of the blade body 1.

[0070] In this embodiment, the material of the vibration isolation unit body 2 is any one of renewable materials, naturally degradable materials, fiber-reinforced resin composite materials, and 3D printing materials, such as wood, carbon fiber-reinforced resin composite materials, and glass fiber-reinforced resin composite materials.

[0071] In this embodiment, as shown in the attached Figure 3 figure, two I-shaped main beams 21 can be arranged inside the cavity 11. The two I-shaped main beams 21 are installed in the same way as the blade body 1, and the two I-shaped main beams 21 are arranged in parallel, which can further enhance the blocking of the low-frequency vibration at the tip of the blade body 1 and enhance the strength and stability of the blade body 1.

[0072] In this embodiment, the shape of the vibration isolation unit body 2 includes concave shape, concave star-shaped angle shape, chiral shape, and other polygons that can contract and expand.

[0073] After considering the specification and practicing the solutions disclosed herein, those skilled in the art will readily conceive of other embodiments of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in this solution. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the claims.

Claims

1. A main beam structure of a wind turbine blade, characterized in that, Comprising: A blade body having a cavity inside; A plurality of vibration isolation unit bodies disposed in the cavity; Each of the vibration isolation unit bodies extends along the length direction of the blade body, and the plurality of vibration isolation unit bodies are arranged in an array in the transverse and vertical directions of the cross section of the blade body. Adjacent two of the vibration isolation unit bodies are connected to each other to form an I-shaped main beam, and two ends of the I-shaped main beam are respectively connected to two sides of the cavity; The vibration isolation unit body includes: Two U-shaped plates; two side walls of the U-shaped plate are arranged obliquely, and two ends of the two U-shaped plates correspond to each other and are connected to each other to enclose a receiving cavity with an opening and form recessed portions on two sides of the vibration isolation unit body; Two connecting plates respectively disposed at two connection portions of the two U-shaped plates.

2. The main beam structure of a wind turbine blade according to claim 1, characterized in that Two U-shaped plates corresponding to two vertically adjacent vibration isolation unit bodies are connected to each other, and two connecting plates corresponding to two horizontally adjacent vibration isolation unit bodies are connected to each other.

3. The main beam structure of a wind turbine blade according to claim 2, characterized in that, The receiving cavity of the vibration isolation unit body and the gaps between adjacent plurality of the vibration isolation unit bodies are filled with a biodegradable thermosetting material.

4. The main beam structure of a wind turbine blade according to claim 3, characterized in that, The biodegradable thermosetting material is any one of epoxy resin, phenolic resin, epoxy acrylate and polyester resin.

5. The main beam structure of a wind turbine blade according to claim 1, characterized in that, Mounting holes are penetrated through the blade body, two ends of the I-shaped main beam are respectively located in the two mounting holes, the side wall of the I-shaped main beam is connected to the side wall of the mounting hole, and a skin is arranged on the outer side of the blade body to block the mounting holes.

6. The main beam structure of a wind turbine blade according to claim 5, characterized in that The top and bottom of the I-shaped main beam are both arc-shaped.

7. The main beam structure of a wind turbine blade according to claim 1, characterized in that, Grooves are provided on the inner top wall and the inner bottom wall of the cavity, two ends of the I-shaped main beam are respectively disposed in the two grooves, and two ends of the I-shaped main beam are respectively connected to the side walls of the cavity.

8. The main beam structure of a wind turbine blade according to claim 1, characterized in that, The material of the vibration isolation unit body is any one of renewable materials, natural degradable materials, fiber reinforced resin composite materials and 3D printing materials.

9. The main beam structure of a wind turbine blade according to claim 1, characterized in that, Two I-shaped main beams are arranged inside the cavity.

Images