Main beam structure of wind turbine blade

Abstract

The main beam structure of the wind turbine blade comprises a blade body and a plurality of vibration isolation unit bodies, a cavity is formed in the blade body and used for improving strength and installing other components, the multiple vibration isolation unit bodies are arranged in the cavity and extend in the length direction of the blade body, and the vibration isolation unit bodies are arranged in the cavity. The multiple vibration isolation unit bodies are arranged in an array mode in the transverse direction and the vertical direction of the section of the blade body, every two adjacent vibration isolation unit bodies are connected to form an I-shaped main beam, and the two ends of each I-shaped main beam are connected with the two sides of the cavity correspondingly. Through the I-shaped main beam formed by the multiple vibration isolation unit bodies and extending of the I-shaped main beam in the length direction of the blade body, the supporting effect on the blade body can be improved, and under the action of the vibration isolation unit bodies, a photonic crystal band gap can be formed to achieve the vibration isolation effect; and low-frequency vibration of the tip end of the blade body is prevented from being transmitted to the root of the blade body to damage the blade body.

Description

Technical Field

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

[0002] Wind turbines, also often referred to as wind turbines, are devices that convert wind energy into electrical energy. The rotor blades are the core components of wind turbines that convert wind energy into mechanical energy. The reliability of the rotor blades plays a vital role in the safe operation of wind turbines. Due to the unpredictable wind speed and direction, the working environment of wind turbines is very complex. The wind rotor is exposed to a series of complex loads such as aerodynamic loads, centrifugal loads, and gravity loads for a long time. The tower has its own natural frequency, and there will also be vibration frequencies when the generator is working. If the frequency of the blade resonates with any of these frequencies, fatigue damage will occur. One of the main factors for blade damage is blade resonance, which will aggravate the fatigue of the blade material and reduce its effective service life. In severe cases, it may even directly cause blade damage and breakage. The load on the fuselage or blades will be amplified due to the resonance phenomenon, and the fuselage or blades will vibrate severely, affecting their power generation efficiency, and in severe cases, they will be damaged.

[0003] When a wind turbine is in operation, the tip of the wind turbine blade will generate low-frequency vibrations under the action of external wind force, and the low-frequency vibrations will be transmitted to the root of the wind turbine blade. However, the wind turbine blades in the prior art cannot effectively block the transmission of low-frequency vibrations at the tip of the wind turbine blade, thereby reducing the durability and stability of the wind turbine blades.

[0004] In view of this, the existing technology still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a main beam structure for 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 blades, thereby reducing the durability and stability of the wind turbine blades.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows: A main beam structure of a wind turbine blade, comprising: A blade body having a cavity inside; A plurality of vibration isolation units are arranged in the cavity; each of the vibration isolation units extends along the length direction of the blade body, and the plurality of vibration isolation units are arranged in a transverse and vertical array along the cross section of the blade body, and two adjacent vibration isolation units are connected to each other to form an I-shaped main beam, and the two ends of the I-shaped main beam are respectively connected to the two sides of the cavity.

[0007] According to the above technical means, the I-shaped main beam formed by multiple vibration isolation units 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, thereby preventing the low-frequency vibration of the tip of the blade body from being transmitted to the root of the blade body and causing damage to the blade body.

[0008] Furthermore, the vibration isolation unit comprises: Two U-shaped plates; the two side walls of the U-shaped plates are arranged obliquely, 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 a recessed portion is formed on both sides of the vibration isolation unit body; The two connecting plates are respectively arranged at the two connecting places of the two U-shaped plates.

[0009] Through the above technical means, two U-shaped plates are arranged relatively and connected to each other to form a structure with a Poisson's ratio, and recessed portions are formed at both ends to facilitate the contraction and expansion of the vibration isolation unit body. At the same time, two laterally adjacent vibration isolation unit bodies can be connected through the connecting plate.

[0010] Furthermore, two U-shaped plates corresponding to two vertically adjacent vibration isolation units are connected to each other, and two connecting plates corresponding to two laterally adjacent vibration isolation units are connected to each other.

[0011] Through the above technical means, by connecting the two U-shaped plates corresponding to the two vertically adjacent vibration isolation units, and connecting the connecting plates corresponding to the two laterally adjacent vibration isolation units, an I-shaped main beam can be formed to facilitate installation.

[0012] Furthermore, the accommodating cavity of the vibration isolation unit body and the gaps between adjacent vibration isolation unit bodies are filled with degradable thermosetting material.

[0013] According to the above-mentioned technical means, through the use of degradable thermosetting materials, not only can the contact area and friction between components be increased, making their connection more firm and reducing loosening and displacement due to vibration or external force during use, but also the risk of structural damage caused by excessive local stress can be reduced, thereby extending the service life of the structure, just like adding a "protective layer" to the gap to buffer and share stress.

[0014] Furthermore, the degradable thermosetting material is any one of epoxy resin, phenolic resin, epoxy acrylate and polyester resin.

[0015] According to the above technical means, a variety of degradable thermosetting materials are provided for selection to facilitate selection for different usage scenarios.

[0016] Furthermore, a mounting hole is provided through the blade body, and the two ends of the I-shaped main beam are respectively located in the two mounting holes, and the side wall of the I-shaped main beam is connected to the side wall of the mounting hole. A skin is provided on the outer side of the blade body to cover the mounting hole.

[0017] According to the above technical means, mounting holes are provided to facilitate the installation and fixation of the I-shaped main beam, while also preventing the I-shaped main beam from being offset relative to the blade body; at the same time, a skin is provided to protect the I-shaped main beam.

[0018] Furthermore, the top and bottom of the I-shaped main beam are both curved.

[0019] According to the above technical means, the top and bottom of the I-shaped main beam are both set as arc-shaped surfaces to facilitate matching with the outer surface of the blade body.

[0020] Furthermore, the inner top wall and the inner bottom wall of the cavity are provided with grooves, and the two ends of the I-shaped main beam are respectively arranged in the two grooves, and the two ends of the I-shaped main beam are respectively connected to the side walls of the cavity.

[0021] Based on 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 setting the I-shaped main beam in the two grooves, which can not only ensure the integrity of the windward and leeward sides of the blade body, but also effectively limit the I-shaped main beam.

[0022] Furthermore, the material of the vibration isolation unit body is any one of renewable materials, naturally degradable materials, fiber-reinforced resin composite materials and 3D printing materials.

[0023] 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.

[0024] Furthermore, two I-shaped main beams are arranged inside the cavity.

[0025] According to the above technical means, two parallel I-shaped main beams are arranged in the cavity, which can effectively improve the blocking effect of the blade body on low-frequency vibration, and at the same time improve the stability of the blade body.

[0026] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the interior of the blade body is provided with a cavity for increasing strength and installing other components. A plurality of vibration isolation units are arranged inside the cavity. The vibration isolation units extend along the length direction of the blade body to increase the contact area between the vibration isolation units and the inner wall of the cavity and improve the supporting force. The plurality of vibration isolation units are arranged in a transverse and vertical array along the cross section of the blade body. Two adjacent vibration isolation units 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 the two 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. The I-shaped main beam formed by the plurality of vibration isolation units and the extension of the I-shaped main beam 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 units, thereby preventing the low-frequency vibration at the tip of the blade body from being transmitted to the root of the blade body and causing damage to the blade body. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the vibration isolation unit of the present invention.

[0029] Figure 3 It is a schematic diagram of the double I-shaped main beam structure of the present invention.

[0030] Figure 4 It is a schematic diagram of the I-shaped main beam and cavity structure of the present invention.

[0031] The numbers in the figure indicate: 1, blade body; 11, cavity; 2, vibration isolation unit; 21, I-shaped main beam; 22, U-shaped plate; 23, connecting plate; 24, accommodating cavity. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and 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.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions 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 only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, 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, unless otherwise specified, "multiple" means two or more.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Modal analysis is a common 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. Based on the research results of the inherent vibration characteristics, it can effectively avoid resonance caused by external excitation and natural frequency, and prevent the damage of mechanical structures.

[0036] At present, many systematic studies have been made on the natural frequency and modal vibration shape 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 weight of the structure. However, the above modal analysis method only improves the shape, thickness or material of the blades, and there are very few structures that increase the vibration resistance of the blade structure. With long-term use, especially in complex environments, wind turbine blades are likely to resonate with the external environment. Although improvements have been made to the structure of the blades, after long-term use, the blades will still be damaged to a certain extent.

[0037] In view of the shortcomings of the prior art, this embodiment provides a main beam structure of a wind turbine blade, which can be specifically referred to as follows: As attached Figure 1 and attached Figure 2As shown, a main beam structure of a wind turbine blade includes a blade body 1 and a plurality of vibration isolation units 2. A cavity 11 is arranged inside the blade body 1. The arrangement 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 part of the circuit of the lightning protection system, sensors for monitoring the state of the blade body 1 (such as strain, temperature, etc.), etc., and it is also convenient for maintaining the blade body 1; a plurality of vibration isolation units 2 are arranged inside the cavity 11, each of which extends along the length direction of the blade body 1 and is in the shape of a long strip. The plurality of vibration isolation units 2 extend along the length direction of the blade body 1 and are in the shape of a long strip. The cross-section of the blade body 1 is arranged in a transverse and vertical array, and two adjacent vibration isolation units 2 are connected to each other to form an I-shaped main beam 21; the vertical 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 multiple vibration isolation units 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 can play a vibration isolation role under the action of the vibration isolation unit 2, thereby preventing the low-frequency vibration of the tip of the blade body 1 from being transmitted to the root of the blade body 1 and causing damage to the blade body 1.

[0038] The vibration isolation unit 2 also has a negative Poisson's ratio characteristic. Through the periodic arrangement of the vibration isolation unit 2 with the negative Poisson's ratio effect, a phononic crystal band gap is formed, which has an isolating effect on the low-frequency vibration generated by the tip of the blade body 1, blocking its transmission to the root of the blade body 1 (the connection between the blade body 1 and the wind turbine shaft), forming a 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 force-bearing part of the blade body 1.

[0039] Negative Poisson's ratio structures have attracted widespread attention due to their many novel and unique properties, such as tensile piezoresistance, porosity / permeability variability with strain, etc. At the same time, compared with ordinary structures, many mechanical properties of negative Poisson's ratio structures have been enhanced. Negative Poisson's ratio is a scale-independent property. Whether at the macroscopic, microscopic or mesoscopic level, the negative Poisson's ratio effect can be achieved, with excellent anti-fatigue, vibration and noise reduction, energy absorption and other characteristics. It is precisely because of the excellent properties of negative Poisson's ratio structures and the scales they cover that they are widely used.

[0040] The vibration isolation unit 2 and the combined I-shaped main beam 21 in the present application realize that the large-scale wind turbine structure has vibration isolation and anti-fatigue functions. This low-frequency vibration isolation and damage-resistant negative Poisson's ratio beam structure changes the elastic modulus, Poisson's ratio and density of the structure in spatial position through the spatial arrangement and change of the vibration isolation unit 2. The size of the overall structure of the blade body 1 can be calculated according to the buffering and shock absorption requirements, so as to obtain the size, arrangement method and number of vibration isolation units 2 required for each row and column of the vibration isolation unit 2, which effectively improves the resonance phenomenon of the existing blade body 1.

[0041] In one embodiment of the present application, as shown in the attached Figure 2 As shown, 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 entire U-shaped plate 22 is arranged in an isosceles trapezoidal shape. One side of the U-shaped plate 22 has an opening, and the openings of the two U-shaped plates 22 correspond to each other. The two ends of the two U-shaped plates 22 correspond to each other and are connected to each other to enclose a accommodating cavity 24 with an opening. Since the two side walls of the U-shaped plate 22 are inclined, recessed portions are formed on both sides of the vibration isolation unit 2. Through the action of the recessed portions, the vibration isolation unit 2 can have the characteristics of contraction and expansion; and a connecting plate 23 is respectively arranged at the connection of the two U-shaped plates 22, and the connecting plate 23 is used to connect with the adjacent vibration isolation unit 2 to improve the stability of the I-shaped main beam 21.

[0042] Through the combined arrangement of the two U-shaped plates 22, the vibration isolation unit 2 can have a negative Poisson's ratio effect. By connecting the two adjacent vibration isolation unit bodies 2 through the bottom plate of the U-shaped plate 22 and through the connecting plate 23, 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, blocking 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.

[0043] As attached Figure 4 As shown, the connecting plate 23 and the U-shaped plate 22 are both extended along the length direction of the blade body 1, and 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 a spaced 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, it can be transmitted to the adjacent vibration isolation unit 2 through the connecting plate 23, so as to achieve the effect of dispersing and reducing the force.

[0044] In this embodiment, the two U-shaped plates 22 corresponding to the two vertically adjacent vibration isolation units 2 are connected to each other, and the two corresponding U-shaped plates 22 facing each other are flat, which can be connected by welding, sintering or bonding, so as to improve the vertical stability of the I-shaped main beam 21, while also ensuring that the force can be dispersed in the vertical direction; the two connecting plates 23 corresponding to the two laterally adjacent vibration isolation units 2 are connected to each other, so that the laterally adjacent vibration isolation units 2 are connected, providing the I-shaped main beam 21 with stability in its laterally direction.

[0045] In this embodiment, the vertical direction of the I-shaped main beam 21 is the up-down direction of the cross section of the blade body 1 , and the lateral direction of the I-shaped main beam 21 is the left-right direction of the cross section of the blade body 1 .

[0046] In this embodiment, the accommodating cavity 24 of the vibration isolation unit 2 and the gaps between the adjacent vibration isolation units 2 are filled with degradable thermosetting materials; in the I-shaped main beam 21 composed of multiple vibration isolation units 2, the degradable thermosetting materials filled in the gaps inside are 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 loosening and displacement caused by vibration or external force during use; when the I-shaped main beam 21 is subjected to external force, the gap is often a weak link where stress is concentrated. After filling with degradable thermosetting materials, it can participate in the force transmission and dispersion process, and disperse the stress originally concentrated at the edge of the gap to a larger filling material area and the structural components connected thereto, reducing the risk of structural damage caused by excessive local stress and extending the service life of the structure, just like adding a "protective layer" to the gap to buffer and share stress.

[0047] In this embodiment, the degradable thermosetting materials can be arranged at intervals, that is, there is a accommodating cavity 24 of a vibration isolation unit 2 or a gap formed by multiple vibration isolation unit bodies 2 between two vertically adjacent degradable thermosetting materials. By arranging them at intervals, the transmission of low-frequency vibrations can be further isolated.

[0048] Furthermore, the degradable thermosetting material may also be filled on the outer surface of the I-shaped main beam 21 through a mold to facilitate the sealing effect after the I-shaped main beam 21 is connected to the blade body 1.

[0049] Furthermore, the degradable thermosetting material is any one of epoxy resin, phenolic resin, epoxy acrylate and polyester resin.

[0050] In this embodiment, the degradable thermosetting material can also be replaced with a degradable thermoplastic material to facilitate recycling. The degradable thermoplastic material can be PBS (polybutylene succinate) or plastic, etc.

[0051] 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, and the side walls of the I-shaped main beam 21 are connected to the side walls of the mounting holes, so that the I-shaped main beam 21 is connected to the blade body 1 .

[0052] The blade body 1 includes a windward surface and a leeward surface. The external wind acts on the windward surface, and under the action of the windward surface, the blade body 1 is driven to rotate, and the mounting hole passes through the windward surface and the leeward surface; the windward surface and the leeward surface are generally arc-shaped surfaces, and the top and bottom of the I-shaped main beam 21 can also be provided with arc surfaces, so as to cooperate with the windward surface and the leeward surface, so as to avoid the formation of bumps or grooves on the windward surface and the leeward surface, so that the external wind acts on the protruding I-shaped main beam 21 or the recessed I-shaped main beam 21, thereby making the force condition of the windward surface disordered, resulting in uneven distribution of the force outside the blade body 1, affecting the service life of the blade body 1.

[0053] In this embodiment, Figure 1 The vibration isolation unit 2 is relatively large in size, and an effective arc surface 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 2 can be reduced, so that more vibration isolation units 2 can be arranged in the vertical and horizontal directions of the I-shaped main beam 21 to form irregular arc surfaces at the top and bottom of the I-shaped main beam 21, and then covered with degradable thermosetting materials to form arc surfaces corresponding to the windward side and the leeward side.

[0054] Specifically, a plurality of rows of vibration isolation units 2 may be arranged in the horizontal direction on the top of the I-shaped main beam 21, and the plurality of rows of vibration isolation units 2 may be vertically stacked. Where an arc surface needs to be formed, the vertical vibration isolation units 2 may be correspondingly reduced, thereby forming a height difference on the top of the I-shaped main beam 21 to facilitate the formation of an arc surface; the left and right side walls of the mounting hole may be connected to the connecting plates 23 of the plurality of vibration isolation units 2, and the other two side walls of the mounting hole may be directly connected to the side walls of the U-shaped plates 22 of the plurality of vibration isolation units 2.

[0055] The mounting hole and the vibration isolation unit body 2 can be connected by welding, bonding, sintering or nesting.

[0056] Furthermore, a skin is provided on the outer side of the blade body 1, and the skin is used to cover the mounting hole, and also provides protection for the I-shaped main beam 21, so as to prevent the external wind from directly acting on the I-shaped main beam 21 and causing a certain impact on the I-shaped main beam 21.

[0057] Through the function of the mounting hole, the I-shaped main beam 21 can be embedded in the blade body 1 and then connected by welding, bonding, sintering or nesting; when the blade body 1 vibrates, the I-shaped main beam 21 will not be displaced relative to the blade body 1 by connecting by embedding, 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.

[0058] In this embodiment, grooves may be provided on the inner top wall and the inner bottom wall of the cavity 11, and the two ends of the I-shaped main beam 21 are respectively provided 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 walls of the blade body 1, thereby ensuring the integrity of the windward and leeward sides of the blade body 1, reducing the changes to the overall structure of the blade body 1, and through the cooperation of the grooves and the I-shaped main beam 21, the grooves can also limit the lateral direction of the I-shaped main beam 21, so that when the blade body 1 vibrates or shakes, the I-shaped main beam 21 will not be displaced relative to the blade body 1.

[0059] By providing grooves on the inner top wall and the inner bottom wall of the cavity 11 , not only the integrity of the windward side and the leeward side of the blade body 1 can be ensured, but also the I-shaped main beam 21 can be effectively limited.

[0060] The corresponding 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, the top wall and the bottom wall of the I-shaped main beam 21 can be connected to the blade body 1 through welding, bonding or sintering, thereby 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 connected to the side walls of the groove, support force can also be provided for the windward surface of the blade body 1 to make up for the defect of opening the groove on the inner side of the windward surface.

[0061] 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 pushing the blade body 1 to rotate. However, such a design will also cause the force of the external wind on the surface of the blade body 1 to tilt in the spiral direction, thereby causing uneven force on the surface of the blade body 1.

[0062] 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. The spirally arranged I-shaped main beam 21 abuts against the inner wall of the cavity 11, so that the force of the external wind can act on the I-shaped main beam 21, and then be dispersed and transmitted to the back side of the blade body 1 by the I-shaped main beam 21, thereby reducing the direct effect of the external wind on the windward side of the blade body 1.

[0063] In this embodiment, the material of the vibration isolation unit 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.

[0064] In this embodiment, as shown in the attached Figure 3 As shown, two I-shaped main beams 21 may be provided inside the cavity 11. The two I-shaped main beams 21 are installed in the same manner as the blade body 1. The two I-shaped main beams 21 are arranged in parallel, which can further enhance the blocking of the low-frequency vibration of the tip of the blade body 1, as well as enhance the strength and stability of the blade body 1.

[0065] In this embodiment, the shapes of the vibration isolation unit body 2 include a concave shape, a concave star-shaped angle shape, a chiral shape, and other shapes that can be contracted and expanded.

[0066] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the schemes disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this scheme. The description and examples are to be regarded as exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

Claims

1. A main beam structure of a wind turbine blade, characterized in that: include: A blade body having a cavity inside; A plurality of vibration isolation units are arranged in the cavity; Each of the vibration isolation units extends along the length direction of the blade body, and a plurality of the vibration isolation units are arranged in a transverse and vertical array along the cross section of the blade body. Two adjacent vibration isolation units are connected to each other to form an I-shaped main beam, and the two ends of the I-shaped main beam are respectively connected to the two sides of the cavity.

2. The main beam structure of a wind turbine blade according to claim 1, characterized in that: The vibration isolation unit comprises: Two U-shaped plates; the two side walls of the U-shaped plates are arranged obliquely, 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 a recessed portion is formed on both sides of the vibration isolation unit body; Two connecting plates are respectively arranged at two connecting places of the two U-shaped plates.

3. The main beam structure of a wind turbine blade according to claim 2, characterized in that: The two U-shaped plates corresponding to the two vertically adjacent vibration isolation units are connected to each other, and the two connecting plates corresponding to the two laterally adjacent vibration isolation units are connected to each other.

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

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

6. The main beam structure of a wind turbine blade according to claim 1, characterized in that: The blade body is penetrated with mounting holes, the two ends of the I-shaped main beam are respectively located in the two mounting holes, the side walls of the I-shaped main beam are connected to the side walls of the mounting holes, and a skin is provided on the outer side of the blade body to cover the mounting holes.

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

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

9. 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, naturally degradable materials, fiber-reinforced resin composite materials and 3D printing materials.

10. 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.

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