Blade root pre-buried bolt sleeve structure

Abstract

The utility model discloses a blade root preburied bolt sleeve structure, including preburied bolt sleeve body, preburied bolt sleeve body is equipped with the internal thread section, transition section and dovetail section that arrange gradually in, the dovetail section is located preburied bolt sleeve body one end. The utility model has the advantages of good bearing capacity, little internal thread section fatigue failure risk and internal thread section not easy to damage.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine blade technology, and in particular to a blade root pre-embedded bolt sleeve structure. Background Technology

[0002] With the rapid development of the wind power industry, the single unit capacity of wind turbines is constantly increasing, and the length and weight of wind turbine blades are continuously increasing. The dynamic alternating load on the blade root is becoming increasingly severe, which puts forward higher requirements for the blade root connection system. As a key component of the blade root connection, the pre-embedded bolt sleeve's structural design and load-bearing capacity performance directly determine the safety and economy of the entire wind power system.

[0003] Chinese patent document CN110778448A discloses a pre-embedded threaded sleeve at the blade root of a wind turbine blade. The small end of the tapered sleeve structure is the blade tip threaded sleeve end and is machined with internal threads. The small end of the tapered sleeve structure has a dovetail groove. The applicant found that in this technical solution, the internal thread is set close to the dovetail groove, which creates a geometric abrupt change zone. The stress at the dovetail groove will be transmitted to the internal thread, increasing the risk of fatigue failure of the internal thread. When the internal thread is close to the edge of the dovetail groove, it is easily damaged by friction or external stress during assembly or use, making the internal thread susceptible to damage and resulting in high maintenance costs. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a blade root pre-embedded bolt sleeve structure with good load-bearing capacity, low risk of fatigue failure of the internal thread section, and easy damage to the internal thread section.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A leaf root pre-embedded bolt sleeve structure includes a pre-embedded bolt sleeve body, wherein an internal thread section, a transition section and a dovetail section are arranged sequentially within the pre-embedded bolt sleeve body, and the dovetail section is located at one end of the pre-embedded bolt sleeve body.

[0007] As a further improvement to the above technical solution:

[0008] The angle between the inner wall of the pre-embedded bolt sleeve body at the dovetail section and the horizontal plane is 5° to 15°.

[0009] The thickness of the pre-embedded bolt sleeve body at the dovetail section is 0.5mm to 3mm.

[0010] The pre-embedded bolt sleeve body is also provided with a first inner cavity section, which is located at the other end of the pre-embedded bolt sleeve body. The end of the internal thread section near the first inner cavity section is obliquely cut with multiple threads.

[0011] A second inner cavity section is provided between the transition section and the dovetail section, and the second inner cavity section is used to install the sealing ring and the plug.

[0012] The internal thread section is formed by extrusion or cutting.

[0013] The length of the internal thread section is 80mm to 200mm.

[0014] The pre-embedded bolt sleeve body is cylindrical with an outer diameter of 70mm to 80mm.

[0015] The outer wall of the pre-embedded bolt sleeve body is provided with external teeth. The external teeth are composed of multiple continuous arcs and form a wave-shaped structure. The arcs include a first arc and a second arc. The first arc is located at both ends of the pre-embedded bolt sleeve body, and the second arc is located between the two first arcs. The radius of the first arc is greater than the radius of the second arc.

[0016] The radius of the first arc is 20mm to 30mm, and the radius of the second arc is 8mm to 10mm.

[0017] Compared with the prior art, the advantages of this utility model are:

[0018] 1. The leaf root pre-embedded bolt sleeve structure of this utility model, by setting a dovetail section at one end of the pre-embedded bolt sleeve body, gradually reduces the inner wall thickness at this end, thereby reducing the contact stress between the pre-embedded bolt sleeve body and the surrounding composite material and improving the load-bearing capacity; by setting a transition section between the dovetail section and the internal thread section, the stress transmitted from the dovetail section to the transition section is reduced, thereby reducing the risk of fatigue failure of the internal thread section. Moreover, during assembly, the transition section provides buffering, making the internal thread section less prone to damage and extending the service life of the internal thread section.

[0019] 2. The leaf root pre-embedded bolt sleeve structure of this utility model, by obliquely cutting the screw threads, allows the bolt to smoothly enter the starting position of the internal thread section, which is convenient for assembly; and can transfer the stress concentrated in the first 3 screw threads to the rear threads, reducing the risk of local fracture.

[0020] 3. The blade root pre-embedded bolt sleeve structure of this utility model, by setting a second inner cavity section for installing the sealing ring and plug, can prevent resin from entering the internal thread section position during blade root injection. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the pre-embedded bolt sleeve structure at the leaf root of this utility model.

[0022] Figure 2 This is a cross-sectional view of the leaf root pre-embedded bolt sleeve structure of this utility model.

[0023] Figure 3 for Figure 2Enlarged view of point A in the middle.

[0024] Legend: 1. Embedded bolt sleeve body; 11. Internal thread section; 111. Thread; 12. Transition section; 13. Dovetail section; 14. First inner cavity section; 15. Second inner cavity section; 21. First arc; 22. Second arc. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] like Figures 1 to 3As shown, the blade root pre-embedded bolt sleeve structure of this embodiment includes a pre-embedded bolt sleeve body 1. The pre-embedded bolt sleeve body 1 has an internally threaded section 11, a transition section 12, and a dovetail section 13 arranged sequentially within it. The dovetail section 13 is located at one end of the pre-embedded bolt sleeve body 1. In this embodiment, the blade root pre-embedded bolt sleeve structure, by providing a dovetail section 13 at one end of the pre-embedded bolt sleeve body 1, gradually reduces the inner wall thickness at that end, thereby reducing the contact stress between the pre-embedded bolt sleeve body 1 and the surrounding composite material and improving the load-bearing capacity. Furthermore, by providing a transition section 12 between the dovetail section 13 and the internally threaded section 11, the stress transmitted from the dovetail section 13 to the transition section 12 is reduced, lowering the risk of fatigue failure of the internally threaded section 11. During assembly, the transition section 12 provides buffering, making the internally threaded section 11 less prone to damage and extending its service life.

[0030] Furthermore, in this embodiment, the angle between the inner wall of the pre-embedded bolt sleeve body 1 at the dovetail section 13 and the horizontal plane is 5° to 15°, preferably 6°.

[0031] Furthermore, in this embodiment, the thickness of the end of the pre-embedded bolt sleeve body 1 at the dovetail section 13 is 0.5mm to 3mm, preferably 1.5mm.

[0032] Furthermore, in this embodiment, the pre-embedded bolt sleeve body 1 is also provided with a first inner cavity section 14, which is located at the other end of the pre-embedded bolt sleeve body 1. The end of the internal thread section 11 near the first inner cavity section 14 is obliquely cut with three threads 111. By obliquely cutting the threads 111, the bolt can smoothly enter the starting position of the internal thread section 11, which is convenient for assembly; and the stress concentrated on the first three threads 111 can be transferred to the rear threads, reducing the risk of local fracture.

[0033] Preferably, in this embodiment, the angle between the beveled thread 111 and the horizontal plane is 5°.

[0034] Preferably, in this embodiment, the diameter of the first inner cavity section 14 and the transition section 12 is 45mm, the thread specification of the internal thread section 11 is M422, and the thread of the internal thread section 11 is one of the following: triangular thread, rectangular thread, trapezoidal thread, and sawtooth thread.

[0035] Furthermore, in this embodiment, the length of the first inner cavity segment 14 is 200mm to 290mm, preferably 250mm.

[0036] Furthermore, in this embodiment, a second inner cavity section 15 is provided between the transition section 12 and the dovetail section 13. The second inner cavity section 15 is used to install the sealing ring and the plug, which can prevent the resin from entering the internal thread section 11 when the leaf root is injected.

[0037] Furthermore, in this embodiment, the internal thread segment 11 is extruded, resulting in high thread strength. Of course, in other embodiments, the internal thread segment 11 can also be machined.

[0038] Furthermore, in this embodiment, the length of the internal thread section 11 is 80mm to 200mm, preferably 95mm.

[0039] Furthermore, in this embodiment, the outer wall of the pre-embedded bolt sleeve body 1 is provided with external teeth. The external teeth are composed of multiple continuous arcs forming a wave-shaped structure. The arcs include a first arc 21 and a second arc 22. The first arc 21 is located at both ends of the pre-embedded bolt sleeve body 1, and the second arc 22 is located between the two first arcs 21. The radius of the first arc 21 is larger than the radius of the second arc 22. By providing external teeth on the outer wall of the pre-embedded bolt sleeve body 1, the contact area between the pre-embedded bolt sleeve body 1 and the surrounding composite material is increased, thereby improving the load-bearing capacity. The larger radius of the arcs at both ends of the pre-embedded bolt sleeve body 1 reduces stress concentration at the ends of the pre-embedded bolt sleeve body 1, resulting in better load-bearing capacity. Of course, in other embodiments, the external teeth can also be trapezoidal or threaded, etc.

[0040] Furthermore, in this embodiment, the radius of the first arc 21 is 20mm to 30mm, preferably 25mm; the radius of the second arc 22 is 8mm to 10mm, preferably 9mm.

[0041] Furthermore, in this embodiment, the pre-embedded bolt sleeve body 1 is cylindrical with an outer diameter of 70mm to 80mm, preferably 72mm.

[0042] Furthermore, in this embodiment, the material of the pre-embedded bolt sleeve body 1 can be 42CrMoA or other metal materials, and the strength grade of the pre-embedded bolt sleeve body 1 can be grade 10 or grade 10.9; the surface roughness of the pre-embedded bolt sleeve body 1 is greater than or equal to Ra6.3 and less than or equal to Ra12.5, preferably Ra12.5.

[0043] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make many possible variations and modifications to the technical solution of the present utility model using the methods and techniques disclosed above, or modify it into equivalent embodiments with equivalent changes, without departing from the spirit and technical solution of the present utility model. Therefore, any simple modifications, equivalent substitutions, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the content of the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A leaf root pre-embedded bolt sleeve structure, characterized in that: The device includes a pre-embedded bolt sleeve body (1), which has an internal thread section (11), a transition section (12) and a dovetail section (13) arranged in sequence. The dovetail section (13) is located at one end of the pre-embedded bolt sleeve body (1).

2. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The angle between the inner wall of the pre-embedded bolt sleeve body (1) at the dovetail section (13) and the horizontal plane is 5° to 15°.

3. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The thickness of the pre-embedded bolt sleeve body (1) at the end of the dovetail section (13) is 0.5mm to 3mm.

4. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The pre-embedded bolt sleeve body (1) is also provided with a first inner cavity section (14), the first inner cavity section (14) is located at the other end of the pre-embedded bolt sleeve body (1), and the inner thread section (11) is obliquely cut with multiple threads (111) at the end near the first inner cavity section (14).

5. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: A second inner cavity section (15) is provided between the transition section (12) and the dovetail section (13), and the second inner cavity section (15) is used to install the sealing ring and the plug.

6. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The internal thread section (11) is formed by extrusion or cutting.

7. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The length of the internal thread section (11) is 80mm to 200mm.

8. The leaf root pre-embedded bolt sleeve structure according to claim 1, characterized in that: The pre-embedded bolt sleeve body (1) is cylindrical with an outer diameter of 70mm to 80mm.

9. The leaf root pre-embedded bolt sleeve structure according to any one of claims 1 to 8, characterized in that: The outer wall of the pre-embedded bolt sleeve body (1) is provided with external teeth. The external teeth are composed of multiple continuous arcs and form a wave-shaped structure. The arcs include a first arc (21) and a second arc (22). The first arc (21) is located at both ends of the pre-embedded bolt sleeve body (1), and the second arc (22) is located between the two first arcs (21). The radius of the first arc (21) is greater than the radius of the second arc (22).

10. The leaf root pre-embedded bolt sleeve structure according to claim 9, characterized in that: The radius of the first arc (21) is 20mm to 30mm, and the radius of the second arc (22) is 8mm to 10mm.

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