Blade root assembly, blade and forming method of blade root assembly

Abstract

The invention discloses a blade root assembly, a blade and a forming method of the blade root assembly. The blade root assembly comprises a blade root body and an embedded connecting structure, the blade root body comprises an outer wall, an inner wall and a filler layer, and the filler layer is filled between the inner wall and the outer wall; the pre-embedded connecting structure is embedded in the filler layer and comprises a sleeve and winding layers arranged outside the sleeve, the winding layers comprise a first winding layer and a second winding layer, at least part of the first winding layer is located between the second winding layer and the sleeve, the second winding layer comprises first fibers, and the first fibers are arranged in the sleeve. The included angle between the extension direction of the first fibers and the axial direction of the sleeve is smaller than 90 degrees, and the additional second winding layer is arranged outside the first winding layer, so that the structural strength of the winding layer in the drawing direction of the sleeve is improved, the risk that the winding layer is broken under the action of external force is reduced, and the anti-pulling bearing capacity of the embedded connecting structure is enhanced; and the connection reliability of the embedded connection structure and the blade root body is improved.

Description

Technical Field

[0001] This application belongs to the field of wind power, and in particular relates to a method for forming a blade root assembly, a blade, and a blade root assembly. Background Technology

[0002] With the development of the wind power industry, wind turbine blades are becoming increasingly larger in size, length, and weight, leading to a corresponding increase in the load on the blade root connection. This places higher demands on the connection strength between the blade root and the hub. Currently, blade root connections are mainly achieved through pre-embedded connections.

[0003] The main failures of pre-embedded connection structures are bolt breakage and pull-out damage of the pre-embedded bolt sleeve. To address pull-out damage of the pre-embedded bolt sleeve, related technologies have provided several solutions. For example, in patent application CN115111249A (published September 27, 2022), entitled "A Pre-embedded Bolt Sleeve and a Wind Turbine Generator," the outer surface of the pre-embedded bolt sleeve was modified by designing multiple grooves of varying depths, and the pre-embedded bolt sleeve is wrapped with a fiberglass layer during use. In patent application CN114770984A (published July 22, 2022), entitled "A Bolt Sleeve for Wind Turbine Blade Root Connection and a Method for Improving its Pre-embedded Strength," the external thread of the bolt sleeve was also modified by machining a micro-groove structure, and the grooves are filled with wire harness winding material during use.

[0004] While the above solution strengthens the connection between the bolt sleeve and the wound wire harness, it neglects the inherent strength of the wound wire harness on the surface of the bolt sleeve. The connection strength and reliability of the pre-embedded connection structure still need to be improved. Summary of the Invention

[0005] This application provides a method for forming a blade root assembly, a blade, and a blade root assembly, which can improve the connection strength and reliability of the pre-embedded connection structure.

[0006] In a first aspect, this application provides a leaf root assembly, the leaf root body including an outer wall, an inner wall and a filler layer, the filler layer filling between the inner wall and the outer wall; a pre-embedded connection structure embedded in the filler layer, the pre-embedded connection structure including a sleeve and a winding layer disposed outside the sleeve, the winding layer including a first winding layer and a second winding layer, at least a portion of the first winding layer being located between the second winding layer and the sleeve, the second winding layer including a first fiber, the angle between the extension direction of the first fiber and the axial direction of the sleeve being less than 90°.

[0007] In some embodiments, the pre-embedded connection structure further includes a wedge block, the hardness of which is less than that of the sleeve, the wedge block being connected to one end of the sleeve facing the blade tip, one end of the second winding layer being connected to the sleeve, and the other end extending to the wedge block.

[0008] In some embodiments, the outer diameter of the wedge block is larger than the outer diameter of the sleeve, and the second winding layer includes a first segment and a second segment connected to each other. The first segment is disposed on the outside of the sleeve, the second segment is disposed on the outside of the wedge block, and the thickness of the second segment is less than the thickness of the first segment.

[0009] In some embodiments, the second winding layer further includes a second fiber, the extension direction of which intersects the extension direction of the first fiber, and the first fibers are connected by the second fiber to form a fabric.

[0010] In some embodiments, the pre-embedded connection structure further includes fixing blocks, with two fixing blocks disposed on both sides of the sleeve, at least a portion of the second winding layer located between the fixing blocks and the sleeve, and the distance L1 between the outer surface of the second winding layer and its adjacent fixing block satisfies L1≤1mm; and / or, at least a portion of the second winding layer is located between at least one of the outer wall and the inner wall and the sleeve, and the distance L2 between the outer surface of the second winding layer and the inner wall or the outer wall satisfies L2≤1mm.

[0011] In some embodiments, a second winding layer is provided with an end-to-end circumferential sleeve.

[0012] In some embodiments, the second winding layer includes a first segment and a second segment connected to each other, the second segment being disposed at at least one end of the first segment in the axial direction, and the thickness of the second segment gradually decreasing in the direction away from the first segment.

[0013] In some embodiments, the outer peripheral surface of the sleeve is provided with a groove, the first winding layer is disposed in the groove, and the height difference h between the side of the first winding layer away from the bottom of the groove and the groove opening satisfies h≤1mm.

[0014] In some embodiments, the angle between the extension direction of at least a portion of the first fiber and the axial direction is... 1. The angle between the fiber extension direction and the axial direction within the first winding layer. 2. Satisfy 1 < 2.

[0015] Secondly, embodiments of this application also provide a blade, including the blade root assembly described in the first aspect embodiment above.

[0016] Thirdly, this application also provides a method for molding a leaf root assembly, used to mold the leaf root assembly of the first aspect embodiment described above. The molding method includes: The first winding layer is wound around the outer circumference of the sleeve; The second winding layer is disposed on the outside of the first winding layer and fixed to the sleeve and / or the first winding layer to form a pre-embedded connection structure. The second winding layer includes a first fiber, and the angle between the extension direction of the first fiber and the axial direction of the sleeve is less than 90°. The pre-embedded connection structure is set between the outer wall and the inner wall of the blade body; A medium is injected between the outer and inner walls to form a filling layer.

[0017] In some embodiments, the second winding layer further includes second fibers, the extension direction of which intersects the extension direction of the first fibers, and the first fibers are connected by the second fibers to form a fabric. The second winding layer is disposed outside the first winding layer and fixed to the sleeve and / or the first winding layer to form a pre-embedded connection structure including: The fabric is wound around the outer circumference of the sleeve to form a second winding layer.

[0018] This application provides a blade root assembly, a blade, and a method for forming the blade root assembly. The blade root assembly includes a blade root body and a pre-embedded connection structure. The pre-embedded connection structure is embedded in the filler layer to form an integral whole with the blade root body, enhancing the connection strength between the two. The pre-embedded connection structure includes a sleeve for bolt connection and a winding layer disposed outside the sleeve. The winding layer includes a first winding layer and a second winding layer. The first winding layer enhances the connection strength between the sleeve and the blade root body. At least a portion of the first winding layer is located between the second winding layer and the sleeve. The second winding layer includes a first fiber, and the angle between the extension direction of the first fiber and the axial direction of the sleeve is less than 90°. In this application embodiment, by providing an additional second winding layer outside the first winding layer, it helps to improve the structural strength of the winding layer in the sleeve pull-out direction, reduce the risk of the winding layer breaking under external force, enhance the pull-out resistance of the pre-embedded connection structure, and improve the connection reliability between the pre-embedded connection structure and the blade root body. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the leaf root assembly provided in some embodiments of this application; Figure 2 for Figure 1 Enlarged structural diagram at point A; Figure 3 This is a schematic diagram of the structure of the second winding layer of the leaf root assembly provided in some embodiments of this application; Figure 4 This is a schematic diagram illustrating the fabrication of the second winding layer of the leaf root assembly provided in some embodiments of this application; Figure 5This is a partial structural schematic diagram of the leaf root assembly provided in some embodiments of this application; Figure 6 for Figure 5 Enlarged structural diagram at point B; Figure 7 for Figure 5 Enlarged structural diagram at point C; Figure 8 This is a schematic diagram of the forming method of the leaf root component provided in some embodiments of this application.

[0021] Explanation of reference numerals in the attached figures: 1. Leaf root assembly; 2. Leaf base body; 21. Outer wall; 22. Inner wall; 3. Embedded connection structure; 31. Sleeve; 311. Groove; 32. Winding layer; 33. First winding layer; 34. Second winding layer; 35. Wedge block; 341. First segment; 342. Second segment; 36. Fixing block; 343. Main body segment; 344. Thinning segment; X, Axial direction. Detailed Implementation

[0022] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0023] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0024] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0025] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0026] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the leaf root assembly provided in some embodiments of this application; Figure 2 for Figure 1 A magnified structural diagram of point A in the middle.

[0027] Firstly, such as Figure 1 and Figure 2 As shown, this application provides a blade root assembly 1, which includes a blade root body 2 and a pre-embedded connection structure 3. The blade root body 2 includes an outer wall 21, an inner wall 22 and a filler layer (not shown in the figure), and the filler layer fills the space between the inner wall 22 and the outer wall 21. The pre-embedded connection structure 3 is embedded in the filler layer and includes a sleeve 31 and a winding layer 32 disposed outside the sleeve 31. The winding layer 32 includes a first winding layer 33 and a second winding layer 34. At least a portion of the first winding layer 33 is located between the second winding layer 34 and the sleeve 31. The second winding layer 34 includes a first fiber, and the angle between the extension direction of the first fiber and the axial direction X of the sleeve 31 is less than 90°.

[0028] In the embodiment of this application, the blade root assembly 1 includes a blade root body 2 and a pre-embedded connection structure 3. The pre-embedded connection structure 3 is embedded in the filler layer to form an integral whole with the blade root body 2, thereby enhancing the connection strength between the two. The pre-embedded connection structure 3 includes a sleeve 31 for bolt connection and a winding layer 32 disposed outside the sleeve 31. The winding layer 32 includes a first winding layer 33 and a second winding layer 34. The first winding layer 33 can enhance the connection strength between the sleeve 31 and the blade root body 2. At least a portion of the first winding layer 33 is located between the second winding layer 34 and the sleeve 31. The second winding layer 34 includes a first fiber. The angle between the extension direction of the first fiber and the axial direction X of the sleeve 31 is less than 90°. In this embodiment of the application, by providing an additional second winding layer 34 outside the first winding layer 33, it helps to improve the structural strength of the winding layer 32 in the pull-out direction of the sleeve 31, reduce the risk of the winding layer 32 breaking under external force, enhance the pull-out resistance of the pre-embedded connection structure 3, and improve the connection reliability between the pre-embedded connection structure 3 and the blade root body 2.

[0029] For example, the outer wall 21 of the leaf root body 2 can be an upper layer structure of the leaf root, and the inner wall 22 of the leaf root body 2 can be an under layer structure of the leaf root.

[0030] Exemplarily, the outer wall 21 and the inner wall 22 are connected to form a cavity, and a filler layer is formed after the resin solidifies by pouring resin into the cavity.

[0031] For example, sleeve 31 can be a bolt sleeve, which is used to connect with external connecting bolts.

[0032] Optionally, the first winding layer 33 is formed of yarn wound around the outer surface of the sleeve 31. Exemplarily, the yarn is continuously wound circumferentially from the root end of the sleeve 31 to the tip end of the sleeve 31 to form the first winding layer 33. Exemplarily, the first winding layer 33 is formed of one or more yarns.

[0033] Optionally, if at least a portion of the first winding layer 33 is located between the second winding layer 34 and the sleeve 31, then the second winding layer 34 is disposed outside the first winding layer 33, or the orthographic projection of the second winding layer 34 and the first winding layer 33 on the surface of the sleeve 31 at least partially overlaps.

[0034] Optionally, the second winding layer 34 includes a first fiber, and at least a portion of the first winding layer 33 is located between the first fiber and the sleeve 31.

[0035] For example, the first fiber may be glass fiber, carbon fiber, or metal fiber, etc.

[0036] Optionally, the extension direction of the first fiber intersects or is parallel to the axial direction X of the sleeve 31. The axial direction X of the sleeve 31 is the direction in which the sleeve 31 is pulled out under the action of external force, or in other words, the axial direction X of the sleeve 31 is the direction of the pulling force acting on the sleeve 31 during the operation of the blade.

[0037] Optionally, the second winding layer 34 consists of only one or more first fibers. Before resin infusion, the second winding layer 34 can be fixed to the sleeve 31 by means of wire harness binding, adhesive bonding, or clamping. For example, the first fiber extends along the axial direction X of the sleeve 31, and multiple first fibers are arranged along the circumferential direction of the sleeve 31 to effectively improve the structural strength of the winding layer 32 in the pull direction of the sleeve 31. Alternatively, the extension direction of the first fiber intersects with the axial direction X of the sleeve 31, and multiple first fibers are arranged parallel to each other and spirally wound around the outer circumferential surface of the sleeve 31.

[0038] Optionally, the second winding layer 34 includes a first fiber and a second fiber, which are connected to form a fabric. Exemplarily, the second winding layer 34 is formed by one or more fabrics disposed on the outer periphery of the sleeve 31.

[0039] Optionally, the second winding layer 34 is disposed on at least a portion of the outer peripheral side surface of the sleeve 31. For example, the second winding layer 34 is wound end to end on the outer peripheral side surface of the sleeve 31 in the circumferential direction to uniformly apply the pull-out force of the pre-embedded connection structure 3; or the second winding layer 34 is disposed only on a portion of the outer peripheral side surface of the sleeve 31 to save the material cost of the winding layer 32.

[0040] Optionally, in the axial direction X, the length of the second winding layer 34 is greater than or equal to the length of the sleeve 31, which on the one hand helps the resin to spread evenly, and on the other hand helps the winding layer 32 to distribute the pull-out force over a larger area.

[0041] Optionally, at least a portion of the first fiber extends at an angle to the axial direction X. 1. The angle between the fiber extension direction and the axial direction X within the first winding layer 33 2. Satisfy 1 < 2. When the angle between the extension direction of at least a portion of the first fiber and the axial direction X satisfies the above conditions, the structural strength of the winding layer 32 in the pulling direction of the sleeve 31 can be effectively improved by providing an additional second winding layer 34.

[0042] For example, the extension direction of the first fiber is parallel to the axial direction X of the sleeve 31. 1 = 0.

[0043] In some embodiments, such as Figure 1 and Figure 2 As shown, the pre-embedded connection structure 3 also includes a wedge block 35. The hardness of the wedge block 35 is less than that of the sleeve 31. The wedge block 35 is connected to the end of the sleeve 31 facing the blade tip. One end of the second winding layer 34 is connected to the sleeve 31, and its other end extends to the wedge block 35.

[0044] In these embodiments, one end of the second winding layer 34 is connected to the sleeve 31, and the other end extends to the wedge block 35. The second winding layer 34 transmits tension between the sleeve 31 and the wedge block 35 to alleviate the problem of stress concentration at the end of the sleeve 31 caused by the sudden change in modulus due to the connection of the sleeve 31 to the wedge block 35.

[0045] Optionally, the wedge block 35 can be a foam wedge block, which is disposed between the sleeve 31 and the blade body 2 to alleviate the problem of abrupt change in modulus between the sleeve 31 and the blade body 2.

[0046] Optionally, the sleeve 31 is inserted into or bonded to the wedge block 35.

[0047] Optionally, the second winding layer 34 is connected to the wedge block 35 and the sleeve 31 so that external force can be transmitted between the wedge block 35 and the sleeve 31 through the second winding layer 34, thereby improving the problem of stress concentration at the end of the sleeve 31.

[0048] Optionally, the connection between the second winding layer 34 and the sleeve 31 refers to the second winding layer 34 being fixed to the sleeve 31 or fixed to the sleeve 31 by the first winding layer 33 during the preparation of the pre-embedded connection structure 3, and / or the second winding layer 34 being fixed to the sleeve 31 by resin or a filler layer after the blade root assembly 1 is processed. The connection between the second winding layer 34 and the wedge block 35 refers to the second winding layer 34 extending to the wedge block 35 being fixed to the wedge block 35 by resin or a filler layer after the blade root assembly 1 is processed.

[0049] Optionally, the second winding layer 34 extends to one end of the wedge block 35 away from the sleeve 31, or the second winding layer 34 covers the entire outer peripheral side of the wedge block 35.

[0050] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of the second winding layer of the leaf root assembly provided in some embodiments of this application.

[0051] In some embodiments, such as Figure 2 and Figure 3 As shown, the outer diameter of the wedge block 35 is larger than the outer diameter of the sleeve 31. The second winding layer 34 includes a first segment 341 and a second segment 342 that are connected to each other. The first segment 341 is disposed on the outside of the sleeve 31, and the second segment 342 is disposed on the outside of the wedge block 35. The thickness of the second segment 342 is less than the thickness of the first segment 341.

[0052] In these embodiments, the outer diameter of the wedge block 35 is larger than the outer diameter of the sleeve 31. By adjusting the thickness of the first segment 341 and the second segment 342 in the second winding layer 34, the problem of stress concentration caused by the formation of obvious steps in the second winding layer 34 is improved.

[0053] Optionally, the first segment 341 is connected to the sleeve 31, and the second segment 342 is connected to the wedge block 35.

[0054] Optionally, the outer diameter of the wedge block 35 gradually increases in the direction away from the sleeve 31, and the thickness of the second segment 342 gradually decreases in the direction away from the first segment 341, so as to uniformly measure the outer diameter of the second winding layer 34.

[0055] Optionally, in the axial direction X of the sleeve 31, the size of the first segment 341 is greater than or equal to the size of the sleeve 31, and / or in the axial direction X of the sleeve 31, the size of the second segment 342 is greater than or equal to the size of the wedge block 35. On the one hand, this enhances the connection strength between the second winding layer 34 and the sleeve 31 and / or the wedge block 35, and on the other hand, it helps to disperse the external force to a larger range through the second winding layer 34, thereby enhancing the anti-pullout bearing capacity of the pre-embedded connection structure 3.

[0056] Please see Figure 4 , Figure 4 This is a schematic diagram illustrating the preparation of the second winding layer of the leaf root assembly provided in some embodiments of this application.

[0057] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the second winding layer 34 also includes a second fiber, the extension direction of which intersects the extension direction of the first fiber, and each of the first fibers is connected by the second fiber to form a fabric.

[0058] In these embodiments, the second winding layer 34 further includes second fibers, and each of the first fibers is connected by the second fibers to form a fabric. Firstly, this reduces the difficulty of fitting the second winding layer 34 and the sleeve 31 during the processing of the blade root assembly 1. Secondly, the fabric-like second winding layer 34 also helps to evenly diffuse the resin, improves the problem of resin-rich areas easily appearing in the sleeve 31, and enhances the connection strength between the embedded connection structure 3 and the blade root body 2. Thirdly, it also reduces the risk that fiber misalignment during the resin filling process can easily lead to resin-rich areas in the sleeve 31, resulting in insufficient connection strength between the embedded connection structure 3 and the blade root body 2.

[0059] For example, the first fiber is one of the warp or weft yarns of the fabric, and the second fiber is the other of the warp or weft yarns of the fabric.

[0060] Alternatively, the second wrapping layer 34 in the form of fabric can be fixed to the sleeve 31 by adhesive bonding or wire harness fastening.

[0061] Optionally, the second winding layer 34 in the form of a fabric has a stable structure, and during processes such as resin infusion, the fabric is less prone to misalignment and wrinkles, which could lead to problems with resin-rich areas.

[0062] Optionally, the second winding layer 34 is connected end to end with a surrounding sleeve 31. Firstly, this reduces the difficulty of fitting the second winding layer 34 and the sleeve 31 during the processing of the blade root assembly 1. Secondly, it helps the resin to spread evenly in the second winding layer 34, improving the problem of resin enrichment in the sleeve 31 and enhancing the connection strength between the embedded connection structure 3 and the blade root body 2. Thirdly, the second winding layer 34 can disperse the external pull-out force to a wider range, thereby enhancing the connection strength between the embedded connection structure 3 and the blade root body 2.

[0063] Optionally, the second winding layer 34 is formed by winding a whole piece of fabric around the sleeve 31 one or more times. This reduces the difficulty of preparing the second winding layer 34 and reduces the number of seams in the second winding layer 34, thereby improving its pull-out resistance.

[0064] Exemplarily, the fabric can be a uniaxial, biaxial, or triaxial fabric, etc. Exemplarily, the fabric is a three-dimensional fabric with fiber connections in the thickness direction. Exemplarily, when the fabric is a uniaxial fabric, the second winding layer 34 includes two uniaxial fabrics, which respectively form an inner layer and an outer layer. The inner layer is located between the outer layer and the sleeve 31. The angle between the extension direction of the reinforcing fibers, or first fibers, in the outer uniaxial fabric and the axial direction X of the sleeve 31 is less than 90°, so as to enhance the structural strength of the second winding layer 34 in the pull direction of the sleeve 31. The angle between the extension direction of the reinforcing fibers in the inner uniaxial fabric and the axial direction X of the sleeve 31 is greater than 0°, so as to provide a clamping force for the sleeve 31.

[0065] Optionally, the second winding layer 34 includes a first segment 341 and a second segment 342 connected to each other. The second segment 342 is disposed at at least one end of the first segment 341 in the axial direction X. Along the direction away from the first segment 341, the thickness of the second segment 342 gradually decreases to reduce the risk of stress concentration caused by the formation of obvious steps on the outer surface of the second winding layer 34.

[0066] For example, the second winding layer 34 includes two second segments 342, which are disposed on both sides of the first segment 341; or the second winding layer 34 includes one second segment 342, which is disposed at one end of the first segment 341 in the axial direction X.

[0067] Please see Figure 5 , Figure 6 and Figure 7 , Figure 5 This is a partial structural schematic diagram of the leaf root assembly provided in some embodiments of this application; Figure 6 for Figure 5 Enlarged structural diagram at point B; Figure 7 for Figure 5 A magnified structural diagram at point C.

[0068] In some embodiments, such as Figure 2 , Figures 5 to 7 As shown, the pre-embedded connection structure 3 also includes a fixing block 36. The two fixing blocks 36 are respectively disposed on both sides of the sleeve 31. At least a portion of the second winding layer 34 is located between the fixing block 36 and the sleeve 31. The distance L1 between the outer surface of the second winding layer 34 and its adjacent fixing block 36 satisfies L1≤1mm; and / or, at least a portion of the second winding layer 34 is located between at least one of the outer wall 21 and the inner wall 22 and the sleeve 31. The distance L2 between the outer surface of the second winding layer 34 and the inner wall 22 or the outer wall 21 satisfies L2≤1mm.

[0069] In these embodiments, when the distance between the outer surface of the second winding layer 34 and the adjacent fixing block 36 and / or the distance between the outer surface of the second winding layer 34 and the inner wall 22 or the outer wall 21 meets the above requirements, it helps to reduce the distance between the winding layer 32 and the fixing block 36 and / or the inner wall 22 and the outer wall 21, reduce the risk of resin-rich problems, and help to improve the connection strength between the pre-embedded connection structure 3 and the leaf root body 2.

[0070] In related technologies, a yarn bundle is wound around the outside of the sleeve 31. The yarn bundle has a compact structure and very little elasticity in the radial direction of the sleeve 31. To facilitate installation, an installation gap and a gap for accommodating resin need to be provided between the yarn bundle and the fixing block 36. This gap is usually greater than or equal to 2 mm. However, in this embodiment, a second winding layer 34 in the form of fabric is provided on the outside of the sleeve 31. Compared with the yarn bundle, the fabric has a looser structure and higher elasticity in the radial direction of the sleeve 31. Therefore, in this embodiment, the overall structure of the winding layer 32 and the sleeve 31 after the second winding layer 34 is provided can be placed between the fixing blocks 36 when the second winding layer 34 is in a compressed state. After installation, the second winding layer 34 expands and resets, reducing the gap size between the second winding layer 34 and the fixing block 36, thus reducing the risk of resin overload. Furthermore, because the fabric itself is relatively loose, the resin can fully impregnate the fabric even with a reduced gap. The reduction in the distance between the outer surface of the second winding layer 34 and the inner wall 22 or outer wall 21 is similar and will not be described in detail here.

[0071] For example, the distance L1 between the outer surface of the second winding layer 34 and its adjacent fixing block 36 can be 0, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, or any value between any two of the above. The distance L2 between the outer surface of the second winding layer 34 and the inner wall 22 or the outer wall 21 is similar and will not be described again here.

[0072] For example, the fixing block 36 can be a UD wedge block, and a sleeve 31 with a winding layer 32 is placed between two adjacent UD wedge blocks.

[0073] In some embodiments, such as Figure 1 and Figure 2 As shown, the outer circumferential surface of the sleeve 31 is provided with a groove 311, the first winding layer 33 is disposed in the groove 311, and the height difference h between the side of the first winding layer 33 away from the bottom of the groove 311 and the opening of the groove 311 satisfies h≤1mm.

[0074] In these embodiments, the first winding layer 33 is disposed in the groove 311 to facilitate fixing the first winding layer 33. When the height difference between the side of the first winding layer 33 away from the bottom of the groove 311 and the groove opening of the groove 311 meets the above conditions, on the one hand, the first winding layer 33 provides a relatively flat connection interface for the second winding layer 34, which facilitates the connection of the second winding layer 34; on the other hand, it reduces the risk of resin-rich areas appearing on the inner sides of the first winding layer 33 and the second winding layer 34.

[0075] Optionally, the height difference h between the side of the first winding layer 33 away from the bottom of the groove 311 and the opening of the groove 311 can be 0, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, or any value between any two of the above values.

[0076] For example, the groove 311 extends along a spiral path on the outer peripheral surface of the sleeve 31.

[0077] For example, the side of the first winding layer 33 facing away from the bottom of the groove 311 is flush with the opening of the groove 311. The filling of the first winding layer 33 provides a flat connection interface for the second winding layer 34, which facilitates the setting of the second winding layer 34. It also reduces the distance between the inner side of the second winding layer 34 and the surface of the sleeve 31, reducing the risk of resin-rich areas appearing between the second winding layer 34 and the sleeve 31.

[0078] Secondly, embodiments of this application also provide a blade, including the blade root assembly described in the first aspect embodiment above.

[0079] Please see Figure 8 , Figure 8 This is a schematic diagram of the forming method of the leaf root component provided in some embodiments of this application.

[0080] Thirdly, such as Figure 1 , Figure 2 and Figure 8 As shown, this application embodiment also provides a method for molding a leaf root component 1, used to mold the leaf root component 1 of the first aspect embodiment described above. The molding method includes: Step S1: Wrap the first winding layer 33 around the outer circumferential surface of the sleeve 31; Step S2: The second winding layer 34 is disposed on the outside of the first winding layer 33 and fixed to the sleeve 31 and / or the first winding layer 33 to form a pre-embedded connection structure 3. The second winding layer 34 includes a first fiber, and the angle between the extension direction of the first fiber and the axial direction X of the sleeve 31 is less than 90°. Step S3: Place the pre-embedded connection structure 3 between the outer wall 21 and the inner wall 22 of the blade body 2; Step S4: Inject a medium between the outer wall 21 and the inner wall 22 to form a filling layer.

[0081] In the embodiments of this application, by providing an additional second winding layer 34 outside the first winding layer 33, it helps to improve the structural strength of the winding layer 32 in the pull-out direction of the sleeve 31, reduce the risk of the winding layer 32 breaking under external force, enhance the anti-pull-out bearing capacity of the pre-embedded connection structure 3, and improve the connection reliability between the pre-embedded connection structure 3 and the blade body 2.

[0082] Optionally, before step S1, the process includes placing a sealing ring and a sealing plug on the sleeve 31 to reduce the risk of resin penetrating the threads of the sleeve 31 during resin injection; sandblasting the surface of the sleeve 31 to improve the roughness and cleanliness of the outer surface of the bolt sleeve; and coating the surface of the sleeve 31 with an epoxy silane coupling agent.

[0083] Optionally, in step S1, the winding direction of the first winding layer 33 is consistent with the direction when the sleeve 31 is pre-tightened.

[0084] Optionally, in step S2, the second winding layer 34 can be fixed to the sleeve 31 or the first winding layer 33 by means of wire harness binding, adhesive bonding or clamping.

[0085] Optionally, the medium can be resin and curing agent. In step S4, resin and curing agent are injected between the outer wall 21 and the inner wall 22 using a vacuum injection method, and then heated and cured to form the desired shape.

[0086] In some embodiments, such as Figures 1 to 4 As shown, the second winding layer 34 further includes second fibers, the extension direction of which intersects the extension direction of the first fibers, and each first fiber is connected through the second fiber to form a fabric. Step S2 includes: The fabric is wound around the outer periphery of the sleeve 31 to form a second winding layer 34.

[0087] In these embodiments, the fabric is wound around the outer periphery of the sleeve 31 to form a second winding layer 34, which reduces the difficulty of preparing the second winding layer 34, and the second winding layer 34 can disperse the external pulling force to a wider range to enhance the connection strength between the embedded connection structure 3 and the leaf root body 2.

[0088] Optionally, the winding direction of the fabric is consistent with the direction in which the sleeve 31 is pre-tensioned.

[0089] Optionally, the fabric includes a main body segment 343 and a thinning segment 344. The thinning segment 344 is disposed on at least one side of the main body segment 343 along its length direction. Along the side away from the main body segment 343, the width of the thinning segment 344 gradually decreases. After the main body segment 343 is wound, it forms a first segment 341 of the second winding layer 34, and after the thinning segment 344 is wound, it forms a second segment 342 of the second winding layer 34. Exemplarily, the fabric is trapezoidal or triangular, etc.

[0090] Optionally, in step S3, the pre-embedded connection structure 3 is disposed between the outer wall 21 and the inner wall 22 of the leaf body 2, the sleeve 31 is connected to the wedge block 35, and the second segment 342 is sleeved on the wedge block 35.

[0091] While the embodiments disclosed in this application are as described above, the content is merely for the purpose of facilitating understanding of this application and is not intended to limit the invention. Any person skilled in the art to which this application pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of protection of this application shall still be determined by the scope defined in the appended claims.

[0092] The above description is merely a specific embodiment of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, substitutions for other connection methods described above can be made by referring to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application.

Claims

1. A leaf root assembly, characterized in that, include: The leaf base body includes an outer wall, an inner wall, and a filler layer, wherein the filler layer fills the space between the inner wall and the outer wall; An embedded connection structure is embedded in the filler layer. The embedded connection structure includes a sleeve and a winding layer disposed outside the sleeve. The winding layer includes a first winding layer and a second winding layer. At least a portion of the first winding layer is located between the second winding layer and the sleeve. The second winding layer includes a first fiber. The angle between the extension direction of the first fiber and the axial direction of the sleeve is less than 90°.

2. The leaf root assembly according to claim 1, characterized in that, The pre-embedded connection structure also includes a wedge block, the hardness of which is less than that of the sleeve. The wedge block is connected to one end of the sleeve facing the blade tip. One end of the second winding layer is connected to the sleeve, and its other end extends to the wedge block.

3. The leaf root assembly according to claim 2, characterized in that, The outer diameter of the wedge block is larger than the outer diameter of the sleeve. The second winding layer includes a first segment and a second segment connected to each other. The first segment is disposed on the outside of the sleeve, and the second segment is disposed on the outside of the wedge block. The thickness of the second segment is less than the thickness of the first segment.

4. The leaf root assembly according to any one of claims 1-3, wherein the leaf root assembly is characterized in that, The second winding layer further includes a second fiber, the extension direction of which intersects the extension direction of the first fiber, and each of the first fibers is connected by the second fiber to form a fabric.

5. The leaf root assembly according to claim 4, characterized in that, The pre-embedded connection structure also includes fixing blocks, with two fixing blocks respectively disposed on both sides of the sleeve. At least part of the second winding layer is located between the fixing blocks and the sleeve. The distance L1 between the outer surface of the second winding layer and the adjacent fixing block satisfies that L1≤1mm. And / or, at least a portion of the second winding layer is located between at least one of the outer wall and the inner wall and the sleeve, and the distance L2 between the outer surface of the second winding layer and the inner wall or the outer wall satisfies L2≤1mm.

6. The leaf root assembly according to claim 4, characterized in that, The second winding layer is arranged around the sleeve with the ends connected.

7. The leaf root assembly according to claim 4, characterized in that, The second winding layer includes a first segment and a second segment connected to each other. The second segment is disposed at at least one end of the first segment in the axial direction, and the thickness of the second segment gradually decreases in the direction away from the first segment.

8. The leaf root assembly according to claim 1, characterized in that, The outer circumferential surface of the sleeve is provided with a groove, the first winding layer is disposed in the groove, and the height difference h between the side of the first winding layer away from the bottom of the groove and the groove opening satisfies h≤1mm.

9. The leaf root assembly according to claim 1, characterized in that, The angle between the extension direction of at least a portion of the first fiber and the axial direction 1. The angle between the fiber extension direction and the axial direction within the first winding layer.

2. Satisfy 1 < 2.

10. A blade, characterized in that, Includes the leaf root assembly as described in any one of claims 1-9.

11. A method for molding a leaf root assembly, used to mold the leaf root assembly according to any one of claims 1-9, characterized in that, The molding method includes: The first winding layer is wound around the outer circumference of the sleeve; The second winding layer is disposed on the outside of the first winding layer and fixed to the sleeve and / or the first winding layer to form a pre-embedded connection structure. The second winding layer includes a first fiber, and the angle between the extension direction of the first fiber and the axial direction of the sleeve is less than 90°. The pre-embedded connection structure is disposed between the outer wall and the inner wall of the leaf body; A medium is injected between the outer wall and the inner wall to form a filling layer.

12. The molding method according to claim 11, characterized in that, The second winding layer further includes a second fiber, the extension direction of which intersects the extension direction of the first fiber, and each of the first fibers is connected by the second fiber to form a fabric. The step of placing the second winding layer outside the first winding layer and fixing it to the sleeve and / or the first winding layer to form a pre-embedded connection structure includes: The fabric is wound around the outer circumference of the sleeve to form the second winding layer.

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