Threaded connection assembly, blade arrangement and wind power plant

Abstract

The present application belongs to the technical field of wind power equipment connecting structure, and particularly relates to a threaded connection assembly, a blade device and a wind power equipment. The threaded connection assembly comprises: an inner threaded connecting piece; and an outer threaded connecting piece, a radially outer side surface of the outer threaded connecting piece is provided with an outer thread, the outer thread is threadedly matched with the inner thread, in the axial tensile stress direction of the outer threaded connecting piece, the outer thread and the inner thread form a plurality of threaded areas, and an axial gap exists between the front side surface of the outer thread of the outer thread and the rear side surface of the inner thread of the inner thread adjacent to the front. Wherein, in the axial tensile stress direction, the axial gap in the threaded area in the front is greater than the axial gap in the threaded area in the rear. Through the technical scheme of the present application, different axial gaps are arranged between the threads in different threaded areas, so as to change the stress distribution according to the axial tensile stress change, so that the overall stress distribution is more uniform, which is beneficial to prolong the service life and reduce the maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wind power equipment connection structure, and particularly relates to a threaded connection assembly, a blade device and a wind power equipment. BACKGROUND

[0002] At present, in the connection mode of the blade in the wind power equipment, the connection bolt is usually matched and connected with the corresponding connection hole on the main machine structure at the blade root. Due to the influence of centrifugal force and other acting forces in the rotating process of the blade, the connection bolt needs to bear a large axial tensile stress. The conventional thread cooperation makes the thread region closer to the blade tip of the connection bolt bear a larger load, and the region farther away from the blade tip bear a smaller load. The stress distribution of the connection bolt is uneven, the stress concentration phenomenon in the local region occurs, the high stress region close to the blade tip produces stress fatigue, and deformation and fracture easily occur in the long-term use process. The service life of the connection bolt is short, and it needs to be frequently replaced, which increases the maintenance cost. SUMMARY

[0003] In view of this, in order to improve at least one of the above problems in the prior art, the present application provides a threaded connection assembly, a blade device and a wind power equipment.

[0004] The first aspect of the present application provides a threaded connection assembly, comprising: an inner threaded connection piece, the inner threaded connection piece is provided with an inner thread; an outer threaded connection piece, the radially outer side of the outer threaded connection piece is provided with an outer thread, the outer thread and the inner thread form a threaded cooperation, in the axial tensile stress direction of the outer threaded connection piece, the outer thread and the inner thread form a plurality of thread regions, and there is an axial gap between the front side of the outer thread of the outer thread and the rear side of the inner thread of the inner thread adjacent to the front. Wherein, in the axial tensile stress direction, the axial gap in the thread region in front is greater than the axial gap in the thread region behind.

[0005] The beneficial effects of the above technical solutions of the present application are as follows:

[0006] Through the improvement and optimization of the structure, the conventional equal-gap threaded cooperation mode is changed, the axial gap between the outer thread and the inner thread in different thread regions is different, so that when bearing the axial tensile stress, the stress distribution is changed according to the size of the axial tensile stress, that is, when the axial tensile stress is relatively small, the thread region behind in the axial direction mainly bears the load, and the thread region bearing the load gradually increases with the increase of the axial tensile stress, so that the overall stress distribution of the threaded connection structure is relatively uniform, the local region stress concentration phenomenon in the conventional threaded cooperation is relieved, and the stress fatigue phenomenon of the threaded connection structure is relieved, which is beneficial to prolong the service life and reduce the maintenance cost.

[0007] In an implementation, the outer thread and the inner thread with the largest axial gap are the largest thread group, and the axial gap of the largest thread group is the largest axial gap.

[0008] The outer thread and the inner thread with the smallest axial gap are the smallest thread group, and the axial gap of the smallest thread group is the smallest axial gap; wherein the largest axial gap is smaller than the sum of the axial elastic deformation of the smallest thread group and the smallest axial gap.

[0009] In an implementation, the sum of the largest axial gap and the axial elastic deformation of the largest thread group is larger than the sum of the smallest axial gap and the axial elastic deformation of the smallest thread group.

[0010] In an implementation, in the initial state, the rear side surface of the outer thread abuts against the front side surface of the rear adjacent inner thread, and the outer thread connection is adapted to move under the action of the axial tensile stress; wherein when the axial tensile stress is greater than the first stress threshold, the axial gap of all thread regions is reduced to zero.

[0011] In an implementation, in the axial tensile stress direction, the distance between the rear side surfaces of any two adjacent outer threads is equal, and the axial thickness of the outer thread in the front thread region is smaller than the axial thickness of the outer thread in the rear thread region; the axial thickness of each inner thread of the inner thread is equal, and the distance between any two adjacent inner threads is equal.

[0012] In an implementation, the nominal diameter of the outer thread is 36 mm, the axial thickness of the outer thread is in the range of 1.95 mm to 2 mm, and the axial gap is in the range of 0.05 mm to 0.1 mm.

[0013] In an implementation, in the axial tensile stress direction, the distance between the front side surfaces of any two adjacent inner threads is equal, and the axial thickness of the inner thread in the front thread region is smaller than the axial thickness of the inner thread in the rear thread region; the axial thickness of each outer thread of the outer thread is equal, and the distance between any two adjacent outer threads is equal.

[0014] In an implementation, the nominal diameter of the inner thread is 36 mm, the axial thickness of the inner thread is in the range of 1.95 mm to 2 mm, and the axial gap is in the range of 0.05 mm to 0.1 mm.

[0015] In an implementation, in the axial tensile stress direction, the plurality of thread regions are sequentially connected, and the axial gap gradually decreases.

[0016] In an implementation, in the axial tensile stress direction, the plurality of thread regions are spaced apart, and the axial gap in the same thread region is equal.

[0017] In an implementation, the radial top of the external thread and / or the internal thread is in the shape of any one of a triangle, a trapezoid or a circular arc; the junction between any two adjacent external threads forms an external thread groove, which is in the shape of any one of a triangle, a trapezoid or a circular arc; the junction between any two adjacent internal threads forms an internal thread groove, which is in the shape of any one of a triangle, a trapezoid or a circular arc.

[0018] In an implementation, the external threaded connector is any one of a bolt, a screw or a threaded rod; and the internal threaded connector is any one of a nut, a threaded sleeve or a threaded hole structure.

[0019] The second aspect of the application also provides a blade device, comprising: a blade body, a blade root connection hole being provided at a blade root joint circle of the blade body; and the threaded connection assembly of any one of the above is arranged in the blade root connection hole.

[0020] The third aspect of the application also provides a wind power equipment, comprising: a main structure, a plurality of blades being rotatably arranged on the main structure; wherein at least one of the blades is the blade device of any one of the above. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Fig. 1 shows a schematic diagram of an implementation of a threaded connection assembly provided by an embodiment of the application.

[0022] Figure 2 Fig. 2 shows a partial schematic diagram of an external thread and an internal thread (initial state) provided by an embodiment of the application.

[0023] Figure 3 Fig. 3 shows a partial schematic diagram of an external thread and an internal thread (a state in which an axial tensile stress is greater than a stress threshold) provided by an embodiment of the application.

[0024] Figure 4 Fig. 4 shows a partial schematic diagram of an external thread and an internal thread (initial state) of a specific implementation provided by an embodiment of the application.

[0025] Figure 5 Fig. 5 shows a partial schematic diagram of an external thread and an internal thread (initial state) of another specific implementation provided by an embodiment of the application.

[0026] Figure 6 Fig. 6 shows a schematic diagram of another implementation of a threaded connection assembly provided by an embodiment of the application.

[0027] Figure 7 Fig. 7 shows a schematic diagram of another specific implementation of an external thread and an internal thread provided by an embodiment of the application.

[0028] Figure 8 The diagram shown is a schematic representation of a specific implementation of an external threaded connector and an internal threaded connector according to an embodiment of the present invention.

[0029] Figure 9 The diagram shown is a schematic diagram of a blade device provided in one embodiment of the present invention.

[0030] Figure 10 The diagram shown is a schematic diagram of a wind power device provided in one embodiment of the present invention.

[0031] In the above figures, arrow F indicates the direction of axial tensile stress, D indicates axial clearance, H indicates the axial thickness of the external thread, h indicates the axial thickness of the internal thread, N indicates the axial spacing of the external thread, and n indicates the axial spacing of the internal thread. Detailed Implementation

[0032] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, top, bottom, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0033] Furthermore, the reference to "embodiment" herein means that a particular 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 separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Application Overview

[0036] In the field of wind power equipment, the blades in the wind power equipment are detachably connected with the main structure on the support tower drum, for example, a connecting hole is arranged at the blade root joint circle of the blade, and the connecting hole is connected with the corresponding connecting hole on the main structure through a connecting bolt. Due to the influence of centrifugal force and other acting forces during the rotation of the blade, the connecting bolt needs to bear a large axial tensile stress, and the strength of the threaded structure between the connecting bolt and the nut directly affects the installation stability of the blade.

[0037] With the continuous development of wind power generation technology, the power generation of the wind turbine and the wind sweeping area of the blade gradually increase, the length of the blade increases, and the load borne by the connecting bolt at the blade root also increases accordingly. The traditional countermeasure is to increase the diameter of the blade root joint circle and the number of connecting bolts, but due to the limitation of objective conditions, the number of blade root joint circles and connecting bolts cannot be increased unlimitedly, thereby limiting the expansion of the length of the blade and the power generation.

[0038] It is found through analysis that the conventional bolt connection mode used in the existing wind power equipment has some defects: in the external thread of the connecting bolt which forms a threaded connection with the nut, since the load of the axial tensile stress needs to be borne, the load borne by the threaded area closer to the blade tip in the axial direction is larger, and the load borne by the area farther away from the blade tip is smaller, the stress distribution of the connecting bolt is uneven, and when the axial tensile stress is large, stress concentration phenomenon in the local area is easily generated, stress fatigue is generated in the high stress area close to the blade tip, and deformation, fracture and other phenomena are easily generated, thereby shortening the service life of the connecting bolt, and the connecting bolt needs to be frequently replaced, thereby increasing the maintenance cost.

[0039] Some embodiments of the threaded connection assembly, the blade device and the wind power equipment in the technical solutions of the present application are provided below.

[0040] In the embodiments of the first aspect of the present application, a threaded connection assembly 1 is provided.

[0041] As shown in Figure 1 and Figure 2 The threaded connection assembly 1 includes an inner threaded connection piece 11 and an outer threaded connection piece 12. The inner threaded connection piece 11 is provided with an inner thread 111, and correspondingly, the radially outer side of the outer threaded connection piece 12 is provided with an outer thread 121, and the outer thread 121 of the outer threaded connection piece 12 can form a threaded connection with the inner thread 111 of the inner threaded connection piece 11, so as to realize bolt connection between the components. When the threaded connection assembly 1 is applied to the wind power equipment and connected with the blade, the threaded connection assembly 1 will be subjected to the axial tensile stress of the blade, and the direction of the axial tensile stress is towards the direction of the axial direction of the outer threaded connection piece close to the blade tip.

[0042] In the axial tension stress direction, the external thread 121 and the internal thread 111 are matched and form a plurality of thread regions, and meanwhile, there is an axial gap between the front side surface of the external thread 121 and the rear side surface of the internal thread 111 adjacent to the front side. Among them, in the axial tension stress direction, the axial gap in the thread region in the front is greater than the axial gap in the thread region in the rear, such as Figure 2 In the example in the figure, the plurality of thread regions include a first thread region 131 in the front and a second thread region 132 in the rear, the axial gap in the first thread region 131 is a first axial gap D1, the axial gap in the second thread region 132 is a second axial gap, and the first axial gap is greater than the second axial gap. Of course, the number of thread regions is not limited to two as shown in Figure 2 In the figure, it can also be other numbers greater than two.

[0043] When the external thread 121 structure is subjected to the action of the axial tension stress, the external thread 121 structure will move along the axial tension stress direction, so that the axial gap is reduced. As an example in Figure 2 In the figure, when the axial tension stress is relatively small, the second axial gap in the second thread region 132 in the rear is first reduced to zero, that is, the front side surface of the external thread 121 in the second thread region 132 is in contact with the rear side surface of the internal thread 111, and the load of the axial tension stress is borne, at this time, the first axial gap in the first thread region 131 in the front is reduced but not completely eliminated, that is, the front side surface of the external thread 121 in the first thread region 131 is not in contact with the rear side surface of the internal thread 111, and the load of the axial tension stress is not borne, that is, at this time, only part of the thread region bears the load of the axial tension stress. When the axial tension stress continues to increase, the external thread connection piece 12 continues to move, so that the external thread 121 and the internal thread 111 in the second thread region 132 are elastically deformed, and at the same time, the front side surface of the external thread 121 in the first thread region 131 is in contact with the rear side surface of the internal thread 111, and bears the load of the axial tension stress, that is, at this time, all the thread regions bear the load of the axial tension stress.

[0044] It can be understood that in the conventional thread matching structure, when not subjected to tensile stress, there is a certain axial gap between the external thread 1211 and the internal thread 1111, and the axial gap between any adjacent external thread 1211 and internal thread 1111 is equal. When subjected to tensile stress, a certain degree of axial displacement occurs between the external thread 1211 and the internal thread 1111, so that the axial gap is reduced until the axial gap is eliminated, so that the front side surface of the external thread 1211 is in close contact with the rear side surface of the internal thread 1111. With the continuous increase of tensile stress, a certain degree of displacement continues to occur, so that a certain degree of axial elastic deformation occurs between the external thread 1211 and the internal thread 1111, and when the tensile stress is eliminated, the original state can be restored. However, if the tensile stress further increases to a certain critical value in the state of elastic deformation, the elastic deformation of the thread will turn into plastic deformation, resulting in bending or even breaking of the thread. Since the axial gaps in the conventional thread structure are equal, but the load distribution of the tensile stress at different positions in the axial direction of the thread structure is not uniform, there is a local stress concentration phenomenon in the front thread, forming a high stress area, which is prone to stress fatigue, bending deformation or even breaking.

[0045] The threaded connection assembly 1 in the embodiment optimizes the setting of the axial gap in the conventional thread matching mode by improving the structure, so that the axial gap between the external thread 121 and the internal thread 111 in different thread regions is different, so that when subjected to axial tensile stress, the stress distribution is changed according to the size of the axial tensile stress, that is, when the axial tensile stress is relatively small, the thread region located in the rear in the axial direction mainly bears the load, and the thread region bearing the load gradually increases with the increase of the axial tensile stress, so that the overall stress distribution of the threaded connection structure is relatively uniform, which can alleviate the local stress concentration phenomenon in the conventional thread matching, and further alleviate the stress fatigue phenomenon of the threaded connection structure, which is beneficial to prolong the service life and reduce the maintenance cost.

[0046] It should be noted that the external thread connection piece 12 in the embodiment of the present application includes but is not limited to a bolt, a screw, a screw rod, and the internal thread connection piece 11 includes but is not limited to a nut, a bolt sleeve, a threaded hole structure. According to different specific application scenarios and actual use requirements, the external thread connection piece 12 and the internal thread connection piece 11 can adopt any one of the above-mentioned various forms. Of course, in addition to the above-mentioned several structural forms, the external thread connection piece 12 and the internal thread connection piece 11 can also adopt other structural forms, and the following embodiments are the same as this, which will not be described hereinafter.

[0047] In a further embodiment of the present application, as Figure 1 and Figure 2As shown, among the different threads of the threaded connection assembly 1, the group of external threads 1211 and internal threads 1111 with the largest axial gap is the largest thread group 141, for example Figure 2 The group of external threads 1211 and internal threads 1111 at the right end of the first thread region 131 is the largest thread group 141, and the axial gap of the largest thread group 141 is the largest axial gap; the group of external threads 1211 and internal threads 1111 with the smallest axial gap is the smallest thread group 142, for example Figure 2 The group of external threads 1211 and internal threads 1111 at the left end of the second thread region 132 is the smallest thread group 142, and the axial gap of the smallest thread group 142 is the smallest axial gap. As the external threaded connection piece 12 moves forward under the action of the axial tensile stress, all the axial gaps gradually decrease, and the largest axial gap is smaller than the sum of the axial elastic deformation of the smallest thread group 142 and the smallest axial gap. When the smallest gap is reduced to zero, the front side surface of the external threads 1211 of the smallest thread group 142 and the rear side surface of the internal threads 1111 have contacted but have not yet occurred axial elastic deformation, and the largest axial gap still has a certain gap amount. Thereafter, as the axial tensile stress continues to increase, the external threaded connection piece 12 continues to move, and at the same time the smallest thread group 142 begins to occur axial elastic deformation; when the largest axial gap is zero, the external threads 1211 and internal threads 1111 in the largest thread group 141 have contacted and can bear the load of the axial tensile stress, and at this time the axial elastic deformation of the smallest thread group 142 has not reached the upper limit value, so that plastic deformation does not occur, and the elastic deformation of the smallest thread group 142 can still restore to the original state, and the smallest thread group 142 does not produce permanent bending deformation and fracture phenomenon.

[0048] Through the setting mode in the embodiment, the external threads 1211 in different thread regions and the corresponding internal threads 1111 can be associated with each other, the stress distribution is optimized, the overall connection strength of the threaded connection assembly 1 is enhanced, and the phenomenon that the low stress region is damaged before the high stress region starts to bear the axial tensile stress load can be effectively prevented.

[0049] Further, as Figure 2As shown, the sum of the maximum axial gap of the threaded connection assembly 1 and the axial elastic deformation variable of the maximum thread group 141 is greater than the sum of the minimum axial gap and the axial elastic deformation variable of the minimum thread group 142, that is, the aforementioned setting mode further adds the factor of the axial elastic deformation variable of the maximum thread group 141. It can be understood that when the external thread 1211 of the maximum thread group 141 is in contact with the internal thread 1111 (the maximum axial gap is reduced to zero), if the axial tensile stress continues to increase, the maximum thread group 141 will also produce an axial elastic deformation. The setting mode of the embodiment can make the elastic deformation of the minimum thread group 142 first reach the upper limit value, that is, if the axial tensile stress continues to increase, the minimum thread group 142 first enters a plastic deformation state, and correspondingly, the minimum thread group 142 first occurs permanent bending deformation or fracture phenomenon.

[0050] Due to the uneven load distribution of the axial tensile stress load in different thread regions, the high-stress region (such as the first thread region 131 in the Figure 2 carries a larger load, and the low-stress region (such as the second thread region 132 in the Figure 2 If the maximum thread group 141 first occurs permanent bending deformation or fracture, it will further weaken the carrying capacity in the high-stress region, causing other threads in the high-stress region to be damaged in turn, and if it is not found in time and maintained, it is extremely likely to cause greater losses or even safety accidents, especially in large outdoor equipment such as wind power equipment. The setting mode in the embodiment can make the minimum thread group 142 first damaged when the axial tensile stress is too large, so as to protect the maximum thread group 141 and other threads in the high-stress region, and the maximum thread group 141 and other threads in the high-stress region can still normally bear the load, which is beneficial to reduce the overall damage degree and prolong the overall service life of the threaded connection assembly 1, and gain time for maintenance and replacement operation.

[0051] In a further embodiment of the present application, as shown in Figures 1 to 3 the rear side surface of the external thread 1211 is in abutment with the front side surface of the rear adjacent internal thread 1111 in the axial tensile stress direction, at this time, there is only an axial gap between the front side surface of the external thread 1211 and the rear side surface of the front adjacent internal thread 1111 between the external threaded connection piece 12 and the internal threaded connection piece 11. When the axial tensile stress acts on the external threaded connection piece 12, the external threaded connection piece 12 produces axial displacement relative to the internal threaded connection piece 11, and the axial gap gradually decreases. Among them, when the axial tensile stress increases to be greater than the first stress threshold, all the external threads 1211 of the external threaded connection piece 12 are in contact with the rear side surface of the front adjacent internal thread 1111, as shown in Figure 3In the example shown, all axial clearances are reduced to zero. This configuration allows each external thread 1211 in the external thread 121 to engage with the corresponding internal thread 1111 and bear the axial tensile stress load, thereby further dispersing the stress and making the axial tensile stress load distribution more uniform, which helps to alleviate local stress concentration.

[0052] The first stress threshold can be set according to specific strength requirements so that all external threads 1211 can fully bear the load before thread damage occurs.

[0053] Furthermore, in a specific implementation, such as Figure 4 As shown, in the direction of axial tensile stress, the distance between the rear faces of any two adjacent external threads 1211 in the external thread 121 is equal, for example... Figure 4 In the first thread region 131, the distance N between adjacent external threads 1211 is equal, and the axial thickness of the external threads 1211 in the preceding thread region is less than the axial thickness of the external threads 1211 in the following thread region, for example... Figure 4 In the first threaded region 131, the axial thickness H1 is less than H2. Correspondingly, in the direction of axial tensile stress, the axial thickness of each internal thread 1111 of the internal thread 111 is equal, and the distance between any two adjacent internal threads 1111 is equal, for example... Figure 4 In the first threaded region 131 shown, the axial thickness of each internal thread 1111 is equal and h, and the distance between adjacent internal threads 1111 is equal and n (based on the front side of the internal thread 1111 in the figure). That is, the internal thread 111 is a conventional thread structure, and the rear side of each external thread 1211 can abut against the front side of the corresponding internal thread 1111. By changing the axial thickness of the external thread 1211, a variable axial spacing structure between the external thread 121 and the internal thread 111 is achieved.

[0054] The axial thickness of the external thread 1211 can decrease sequentially in the axial tensile stress direction, meaning the axial thickness of each preceding external thread 1211 is less than that of each subsequent external thread 1211. Alternatively, the axial thickness of the external thread 1211 can decrease overall in the axial tensile stress direction, but some of the external threads 1211 may have the same axial thickness. The specific thickness can be determined based on actual strength requirements.

[0055] Furthermore, such as Figure 4As shown, the axial thickness H of the external thread 121 is in the range of 1.95mm to 2mm when the nominal diameter of the external thread 121 is 36mm, i.e. the size of the external thread 121 with the minimum axial thickness H is 1.95mm and the size of the external thread 121 with the maximum axial thickness H is 2mm in the axial tensile stress direction; correspondingly, the axial thickness h of the internal thread 111 is equal and can be any size in the range of 1.95mm to 2mm, and the distance n between any two adjacent internal threads 111 is equal and can be 4mm. When the external thread 121 is matched with the internal thread 111, the axial gap D between the external thread 121 and the internal thread 111 is in the range of 0.05mm to 0.1mm, so that the distance N between any two adjacent external threads 121 is in the range of 4mm to 4.05mm.

[0056] In this embodiment, the internal thread connector 11 can adopt a conventional internal thread structure, and only the external thread connector 12 needs to be specially machined and manufactured, and can be used in cooperation with a general internal thread structure (such as a nut, a threaded hole, etc.).

[0057] Further, in another specific implementation manner, as shown in Figure 5 In the axial tensile stress direction, the distance between the front side surfaces of any two adjacent internal threads 111 is equal, for example Figure 5 In the first thread region 131, the distance between the adjacent internal threads 111 is n, and the axial thickness of the internal thread 111 in the front thread region is smaller than the axial thickness of the internal thread 111 in the rear thread region, for example Figure 5 In the first thread region 131, the axial thickness h1 is smaller than the axial thickness h2. Correspondingly, in the axial tensile stress direction, the axial thickness of each external thread 121 in the external thread 121 is equal, for example Figure 5 In the first thread region 131, the axial thickness of the external thread 121 is H, and the distance between any two adjacent external threads 121 is equal, for example Figure 5 In the first thread region 131, the distance between the adjacent two external threads 121 is N (the rear side surface of the external thread 121 is taken as the reference). That is, the external thread 121 is a conventional thread structure, and the rear side surface of each external thread 121 can abut against the front side surface of the corresponding internal thread 111, and the variable axial spacing structure between the external thread and the internal thread 111 is realized by changing the axial thickness of the internal thread 111.

[0058] The axial thickness of the internal thread 1111 can decrease in sequence in the axial tensile stress direction, that is, the axial thickness of the previous internal thread 1111 is smaller than the axial thickness of the subsequent internal thread 1111. Of course, the axial thickness of the internal thread 1111 can also decrease as a whole in the axial tensile stress direction, but the axial thickness of part of the internal thread 1111 can be equal. The actual strength requirement can be set according to the actual strength requirement.

[0059] Further, as shown in Figure 5 When the nominal diameter of the internal thread 111 is 36 mm, the axial thickness h of the internal thread 1111 is in the range of 1.95 mm to 2 mm, that is, the size of the internal thread 1111 with the smallest axial thickness h is 1.95 mm, and the size of the internal thread 1111 with the largest axial thickness h is 2 mm; correspondingly, the axial thickness H of the external thread 1211 is equal, and can be any size in the range of 1.95 mm to 2 mm, the distance N between any two adjacent external threads 1211 is equal, and can be 4 mm. When the external thread 121 is matched with the internal thread 111, the axial gap D between the external thread 1211 and the internal thread 1111 is in the range of 0.05 mm to 0.1 mm, so that the distance n between any two adjacent internal threads 1111 is in the range of 4 mm to 4.05 mm.

[0060] In this embodiment, the external thread connection piece 12 can adopt a conventional external thread structure, and only the internal thread connection piece 11 needs to be specially machined and manufactured, and can be used in cooperation with a general external thread structure (such as a bolt, a screw rod, etc.).

[0061] It should be noted that the above two specific implementation modes can also be combined in actual production and application, and can be set according to the actual design requirement, which will not be described here.

[0062] In a further embodiment of the present application, a specific implementation mode of the threaded connection assembly 1 is provided. As shown in Figures 2 to 4 The plurality of threaded regions are connected in sequence to form a continuous threaded structure, that is, the internal thread 111 and the external thread 121 are both continuous threaded structures. In the axial tensile stress direction, the axial gap between the external thread 1211 and the internal thread 1111 gradually decreases, so that the external thread 121 and the internal thread 111 form a continuously changing threaded structure. It can be understood that the space for forming a threaded connection between the external thread connection piece 12 and the internal thread connection piece 11 is limited, and the continuously changing threaded structure in this embodiment can make full use of the limited space to maximize the contact area between the external thread 121 and the internal thread 111, so that the load distribution is relatively more uniform. The numerical change of the axial gap can adopt a certain series, for example, an arithmetic sequence.

[0063] In a further embodiment of the present application, another implementation of the threaded connection assembly 1 is provided. As shown in Figure 6 and Figure 7 In the axial tensile stress direction, the plurality of threaded regions are spaced apart, i.e. the external thread 121 and the internal thread 111 are discontinuous (non-continuous), as shown in Figure 7 There is an intermittent region between the first threaded region 131 and the second threaded region 132, which can serve as a buffer region that does not bear the load of the axial tensile stress. In addition, due to the different axial clearances in different threaded regions, the intermittent region can serve as a transition region for machining tools and the like during processing, so as to change the size or processing parameters of the machining tool in this region, thereby facilitating the processing of the threaded structure in different threaded regions.

[0064] In the same threaded region, the axial clearance between the external thread 1211 and the internal thread 1111 is equal, for example Figure 7 In the example shown in the above figure, the axial clearance between any adjacent external thread 1211 and internal thread 1111 in the first threaded region 131 is D1, while the axial clearance between any adjacent external thread 1211 and internal thread 1111 in the second threaded region 132 is D2, and D1 is greater than D2. The above arrangement can further simplify the processing process, i.e. the same processing parameters can be set when processing the threads in the same threaded region, which is beneficial to reduce the processing difficulty and the cost of the part.

[0065] In addition, when the number of threaded regions is greater than two, the numerical values of the axial clearances in different threaded regions can adopt a certain sequence, such as an arithmetic sequence.

[0066] In a further embodiment of the present application, as shown in Figure 2 In the threaded connection assembly 1, the radial top of the external thread 1211 is in the shape of a circular arc, and the connection between the two adjacent external threads 1211 forms an external thread groove 1212 in the shape of a circular arc; Correspondingly, the radial top of the internal thread 1111 is also in the shape of a circular arc, and the connection between the two adjacent internal threads 1111 forms an internal thread groove 1112 in the shape of a circular arc. When the external thread 121 and the internal thread 111 are formed in cooperation, the top circular arc structure of the external thread 1211 is matched with the circular arc structure of the corresponding internal thread groove 1112, and the circular arc structure of the external thread groove 1212 is matched with the top circular arc structure of the corresponding internal thread 1111. On the one hand, it can prevent radial collision or interference, and on the other hand, it can alleviate the stress concentration phenomenon of the external thread groove 1212 and the internal thread 1111 through the circular arc structure, so that the stress distribution is more uniform.

[0067] Of course, the specific structure of the screw thread in the present application is not limited to the above-mentioned arc structure, and triangular or trapezoidal structures can also be used according to actual application requirements, which will not be described here.

[0068] Further, in any of the above embodiments, the outer threaded connecting piece 12 and the inner threaded connecting piece 11 in the threaded connecting assembly 1 can adopt different specific structure forms in different application scenarios. For example, the structure form of the outer threaded connecting piece 12 can include any one of a bolt, a screw or a screw rod, and correspondingly, the structure form of the inner threaded connecting piece 11 can include any one of a nut, a bolt sleeve or a threaded hole structure. For example, as shown in Figure 8 , the outer threaded connecting piece 12 is specifically a bolt, and the inner threaded connecting piece 11 is specifically a nut, and the bolt and the nut are matched with each other through the outer thread 121 and the inner thread 111 to connect different components.

[0069] Of course, Figure 8 Only one of the implementation manners, the outer threaded connecting piece 12 and the inner threaded connecting piece 11 can also select other combination manners, such as a screw rod and a nut, a bolt and a threaded hole structure, etc.

[0070] The following is a specific embodiment of the threaded connecting assembly 1 of the present application.

[0071] As shown in Figure 1 and Figure 2 , the threaded connecting assembly 1 includes an inner threaded connecting piece 11 and an outer threaded connecting piece 12. The inner threaded connecting piece 11 is provided with an inner thread 111, and correspondingly, the outer threaded connecting piece 12 is provided with an outer thread 121 on the radially outer side thereof, and the outer thread 121 of the outer threaded connecting piece 12 can be threadedly matched with the inner thread 111 of the inner threaded connecting piece 11 to realize bolt connection between components. When the threaded connecting assembly 1 is applied to wind power equipment and connected to a blade, the threaded connecting assembly 1 will be subjected to an axial tensile stress of the blade, and the axial tensile stress direction is towards the direction of the axial direction of the outer bolt connecting piece close to the blade tip.

[0072] As shown in Figures 2 to 4As shown, in the axial tensile stress direction, the external thread 121 and the internal thread 111 are matched with each other and form a plurality of thread regions, including a front first thread region 131 and a rear second thread region 132, and the first thread region 131 is connected with the second thread region 132 and forms a continuous thread structure. According to the load distribution of the axial tensile stress, the first thread region 131 bears a larger load of the axial tensile stress than the second thread region 132, so the first thread region 131 is a high stress region and the second thread region 132 is a low stress region. Wherein, the radial top of the external thread 1211 of the external thread 121 is arc-shaped, and the external thread groove 1212 formed at the connection between the two adjacent external threads 1211 is also arc-shaped; Correspondingly, the radial top of the internal thread 1111 of the internal thread 111 is also arc-shaped, and the internal thread groove 1112 formed at the connection between the two adjacent internal threads 1111 is also arc-shaped.

[0073] As shown, Figures 2 to 4 in the initial state, in the axial tensile stress direction, the rear side of the external thread 1211 abuts against the front side of the rear adjacent internal thread 1111, and there is an axial gap between the front side of the external thread 1211 and the rear side of the front adjacent internal thread 1111. Wherein, in the axial tensile stress direction, the axial gap in the front thread region is larger than the axial gap in the rear thread region, as shown in the example of Figure 2 , the axial gap in the first thread region 131 is the first axial gap D1, the axial gap in the second thread region 132 is the second axial gap, and the first axial gap is larger than the second axial gap, and in the axial tensile stress direction, the axial gap gradually increases in a connecting manner.

[0074] When the axial tensile stress acts on the external thread connector 12, the external thread connector 12 produces axial displacement relative to the internal thread connector 11, and the axial gap gradually decreases. Wherein, when the axial tensile stress increases to be greater than the first stress threshold, all the external threads 1211 of the external thread connector 12 are in contact with the rear side of the front adjacent internal thread 1111, as shown in the example of Figure 3 , at this time, all the axial gaps are reduced to zero.

[0075] Specifically, as shown in Figure 4 , in the axial tensile stress direction, the distance between the rear sides of any two adjacent external threads 1211 in the external thread 121 is equal, for example Figure 4 , the distance N between the adjacent external threads 1211 in the first thread region 131 is equal, and the axial thickness of the external thread 1211 in the front thread region is smaller than the axial thickness of the external thread 1211 in the rear thread region, for example Figure 4In the first threaded region 131, the axial thickness H1 is less than H2. Correspondingly, in the direction of axial tensile stress, the axial thickness of each internal thread 1111 of the internal thread 111 is equal, and the distance between any two adjacent internal threads 1111 is equal, for example... Figure 4 In the first threaded region 131 shown, the axial thickness of each internal thread 1111 of the internal thread 111 is h, and the distance between adjacent internal threads 1111 is n (based on the front side of the internal thread 1111 in the figure). The axial thickness of the external thread 1211 can decrease sequentially in the axial tensile stress direction. The internal thread 111 has a conventional thread structure, and the rear side of each external thread 1211 can abut against the front side of the corresponding internal thread 1111. By varying the axial thickness of the external thread 1211, a variable axial spacing between the external thread 121 and the internal thread 111 is achieved.

[0076] like Figure 4 In the example, taking an external thread 121 with a nominal diameter of 36mm as an example, the axial thickness H of the external thread 1211 is in the range of 1.95mm to 2mm. That is, in the direction of axial tensile stress, the external thread 1211 with the smallest axial thickness H has a size of 1.95mm, and the external thread 1211 with the largest axial thickness H has a size of 2mm. The corresponding internal threads 1111 have the same axial thickness h, and h is specifically 2mm. The distance between any two adjacent internal threads 1111 is equal to n, and n is specifically 4mm. Therefore, the axial clearance D between the external thread 1211 and the internal thread 1111 is in the range of 0.05mm to 0.1mm, making the distance N between any two adjacent external threads 1211 in the range of 4mm to 4.05mm.

[0077] like Figure 2 In the example, when the axial tensile stress is relatively small, the second axial clearance in the rear second threaded region 132 first decreases to zero, that is, the front side of the external thread 1211 in the second threaded region 132 contacts the rear side of the internal thread 1111, bearing the load of axial tensile stress. At this time, the first axial clearance in the front first threaded region 131 decreases but is not completely eliminated, that is, the front side of the external thread 1211 in the first threaded region 131 does not contact the rear side of the internal thread 1111, and does not bear the load of axial tensile stress. At this time, only a part of the threaded region bears the load of axial tensile stress. When the axial tensile stress is greater than the first stress threshold, the external threaded connector 12 continues to move, causing the external thread 1211 and the internal thread 1111 in the second threaded region 132 to undergo elastic deformation, and at the same time, causing the front side of the external thread 1211 in the first threaded region 131 to contact the rear side of the internal thread 1111, and bear the load of axial tensile stress. At this time, all threaded regions bear the load of axial tensile stress.

[0078] As shown in Figure 2 the rightmost set of external thread 1211 and internal thread 1111 in the first threaded region 131 forms a maximum thread group 141, and the axial gap of the maximum thread group 141 is the maximum axial gap; Figure 2 the leftmost set of external thread 1211 and internal thread 1111 in the second threaded region 132 forms a minimum thread group 142, and the axial gap of the minimum thread group 142 is the minimum axial gap. As the external threaded connector 12 moves forward under the action of the axial tensile stress, all the axial gaps gradually decrease. Among them, the sum of the maximum axial gap of the threaded connection assembly 1 and the axial elastic deformation variable of the maximum thread group 141 is greater than the sum of the minimum axial gap and the axial elastic deformation variable of the minimum thread group 142. When the minimum gap is reduced to zero, that is, the front side surface of the external thread 1211 of the minimum thread group 142 and the rear side surface of the internal thread 1111 have contacted but have not yet occurred axial elastic deformation, the maximum axial gap still has a certain gap amount. Thereafter, as the axial tensile stress continues to increase, the external threaded connector 12 continues to move, and at the same time the minimum thread group 142 begins to occur axial elastic deformation; when the maximum axial gap is zero, the external thread 1211 and the internal thread 1111 in the maximum thread group 141 have contacted and can bear the load of the axial tensile stress, and at this time the axial elastic deformation variable of the minimum thread group 142 has not reached the upper limit value, and the elastic deformation of the minimum thread group 142 can still restore to the original state. If the axial tensile stress continues to increase, the maximum thread group 141 will also produce axial elastic deformation, and the elastic deformation variable of the minimum thread group 142 reaches the upper limit value first, so that the minimum thread group 142 enters the plastic deformation state first, so as to protect the maximum thread group 141 and other threads in the first threaded region 131.

[0079] In another specific implementation manner, as shown in Figure 6 and Figure 7 in the direction of the axial tensile stress, the first threaded region 131 and the second threaded region 132 can also be arranged in a spaced manner, that is, the external thread 121 and the internal thread 111 are both discontinuous structures (non-continuous), wherein the first axial gap between any adjacent external thread 1211 and internal thread 1111 in the first threaded region 131 is equal, and the second axial gap between any adjacent external thread 1211 and internal thread 1111 in the second threaded region 132 is equal.

[0080] In addition, in actual application, according to different application scenarios, the structure form of the external threaded connector 12 can include any one of a bolt, a screw or a screw rod, and correspondingly, the structure form of the internal threaded connector 11 can include any one of a nut, a bolt sleeve or a threaded hole structure. For example Figure 8In the example shown in the figure, the external threaded connecting piece 12 is specifically a bolt, and the internal threaded connecting piece 11 is specifically a nut, and the bolt and the nut are matched with each other through the external thread 121 and the internal thread 111 to connect different components.

[0081] The threaded connecting assembly 1 in the embodiment optimizes the axial gap in the conventional threaded matching mode, so that the axial gaps between the external thread 121 and the internal thread 111 in different threaded regions are different, so as to change the stress distribution according to the size of the axial tensile stress when the axial tensile stress is borne, that is, when the axial tensile stress is relatively small, the threaded region located in the rear in the axial direction mainly bears the load, and the threaded region bearing the load gradually increases with the increase of the axial tensile stress, so that the overall stress distribution of the threaded connecting structure is relatively uniform, which can relieve the phenomenon of local stress concentration in the conventional threaded matching, and further relieve the stress fatigue phenomenon of the threaded connecting structure, which is beneficial to prolong the service life and reduce the maintenance cost.

[0082] According to the analysis of the simulation results, by adopting the threaded connecting assembly 1 in the embodiment, the maximum stress can be reduced from 830MPa to 550MPa, and the stress distribution in other regions is also more uniform.

[0083] In addition, in the embodiment, only the external threaded connecting piece 12 needs to be specially processed, and the internal threaded connecting piece 11 can adopt a conventional internal thread structure, which is more versatile; and compared with the internal thread, the external thread has relatively small difficulty in the processing process, which is beneficial to reduce the processing difficulty and processing cost.

[0084] In the embodiment of the second aspect of the application, a blade device 2 is also provided. As shown in Figure 1 and Figure 9 The blade device 2 includes a blade body 21 and a plurality of threaded connecting assemblies 1 in any of the above embodiments. The blade root connecting hole 212 is provided at the blade root joint circle 211 of the blade body 21, and the threaded connecting assembly 1 is arranged in the blade root connecting hole 212, so as to be connected with the main machine of the wind power equipment through the threaded connecting assembly 1 when the blade device 2 is assembled on the wind power equipment.

[0085] When the blade body 21 rotates, the threaded connecting assembly 1 is subjected to the axial tensile stress of the blade body 21, and the axial tensile stress is along the axial direction of the threaded connecting assembly 1 and towards the blade tip direction of the blade body 21. Through the arrangement of the variable axial gap in the threaded connecting assembly 1, the external thread 1211 and the internal thread 1111 in different threaded regions can bear the load of the axial tensile stress according to the size of the axial tensile stress, so as to optimize the load distribution of the axial tensile stress and make the stress distribution of the threaded connecting assembly 1 more uniform.

[0086] The number of the blade root connecting holes 212 can be multiple, and each blade root connecting hole 212 can be provided with the threaded connecting assembly 1, or only part of the blade root connecting holes 212 can be provided with the threaded connecting assembly 1 according to the actual use requirement, and the other blade root connecting holes 212 can be provided with a conventional bolt and nut structure.

[0087] Further, the threaded connecting assembly 1 can be in the form of a bolt and a nut as shown in Figure 8 .

[0088] In addition, the blade device 2 in the embodiment also has all the beneficial effects of the threaded connecting assembly 1 in any of the above embodiments, which will not be repeated here.

[0089] The embodiment of the third aspect of the application provides a wind power equipment 3, as shown in Figure 1 , Figure 9 and Figure 10 , the wind power equipment 3 comprises a main machine structure 31, and a plurality of blades are rotatably arranged on the main machine structure 31, when the blades rotate under the action of wind, the main machine structure 31 is driven to generate electricity. At least one of the blades is the blade device 2 in any of the above embodiments, so as to enhance the connection strength between the blade device 2 and the main machine structure 31.

[0090] Further, the main machine structure 31 can comprise a hub, a generator set and other supporting devices. In addition, the wind power equipment 3 can also comprise other supporting devices according to the actual use requirement, for example, the support structure 32 shown in Figure 10 .

[0091] In addition, the wind power equipment 3 in the embodiment also has all the beneficial effects of the blade device 2 in any of the above embodiments, which will not be repeated here.

[0092] The basic principles of the application are described above in combination with specific embodiments, but it should be pointed out that the advantages, advantages, effects and the like mentioned in the application are only examples and are not limited, and these advantages, advantages, effects and the like cannot be considered as the must-have of each embodiment of the application. In addition, the above disclosed specific details are only for the purpose of example and understanding, and are not limited to the above specific details, and the above specific details are not limited to the implementation of the application.

[0093] The block diagrams of the devices, apparatuses, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it. It should also be noted that in the apparatuses and devices of this invention, the components can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the invention.

[0094] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

[0095] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features of the invention herein.

[0096] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A threaded connection assembly, characterized in that, The threaded connection assembly comprises: an inner threaded connector (11) provided with an inner thread (111); an outer threaded connector (12) provided with an outer thread (121) on the radially outer side thereof, the outer thread (121) threadedly engages with the inner thread (111), in the axial tensile stress direction of the outer threaded connector (12), the outer thread (121) and the inner thread (111) form a plurality of thread regions, and there is an axial gap between the front side of the outer thread (121) and the rear side of the inner thread (111) adjacent in front; wherein, in the axial tensile stress direction, the axial gap in the thread region in front is greater than the axial gap in the thread region behind; the outer thread (121) and the inner thread (111) of the group of the outer thread (121) with the largest axial gap are the largest thread group (141), and the axial gap of the largest thread group (141) is the largest axial gap; the outer thread (121) and the inner thread (111) of the group of the outer thread (121) with the smallest axial gap are the smallest thread group (142), and the axial gap of the smallest thread group (142) is the smallest axial gap; wherein, the largest axial gap is less than the sum of the axial elastic deformation of the smallest thread group (142) and the smallest axial gap.

2. The threaded connection assembly according to claim 1, wherein: the sum of the largest axial gap and the axial elastic deformation of the largest thread group (141) is greater than the sum of the smallest axial gap and the axial elastic deformation of the smallest thread group (142).

3. The threaded connection assembly according to claim 1, wherein: in the initial state, the rear side of the outer thread (121) abuts against the front side of the inner thread (111) adjacent behind, and the outer threaded connector (12) is adapted to move under the action of the axial tensile stress; wherein, when the axial tensile stress is greater than a first stress threshold, the axial gap of all the thread regions is reduced to zero.

4. The threaded connection assembly according to claim 3, wherein: in the axial tensile stress direction, the distance between the rear sides of any two adjacent outer threads (121) is equal, and the axial thickness of the outer thread (121) in the thread region in front is less than the axial thickness of the outer thread (121) in the thread region behind; the axial thickness of each inner thread (1111) of the inner thread (111) is equal, and the distance between any two adjacent inner threads (1111) is equal.

5. The threaded connection assembly according to claim 4, wherein: the nominal diameter of the outer thread (121) is 36 mm, the axial thickness of the outer thread (1211) is in the range of 1.95 mm to 2 mm, and the axial gap is in the range of 0.05 mm to 0.1 mm.

6. The threaded connection assembly according to claim 3, wherein, in the axial tensile stress direction, the distance between any two adjacent front flanks of the internal threads (1111) is equal, and the axial thickness of the internal thread (1111) in the front thread region is smaller than the axial thickness of the internal thread (1111) in the rear thread region; the axial thickness of each external thread (1211) of the external thread (121) is equal, and the distance between any two adjacent external threads (1211) is equal.

7. The threaded connection assembly according to claim 6, wherein, the nominal diameter of the internal thread (111) is 36 mm, the axial thickness of the internal thread (1111) is in the range of 1.95 mm to 2 mm, and the axial gap is in the range of 0.05 mm to 0.1 mm.

8. The threaded connection assembly according to any one of claims 1 to 7, wherein, in the axial tensile stress direction, a plurality of thread regions are sequentially connected, and the axial gap gradually decreases.

9. The threaded connection assembly according to any one of claims 1 to 7, wherein, in the axial tensile stress direction, a plurality of thread regions are arranged at intervals, and the axial gap in the same thread region is equal.

10. The threaded connection assembly according to any one of claims 1 to 7, wherein, the shape of the radial top of the external thread (1211) and / or the internal thread (1111) is any one of a triangle, a trapezoid, or a circular arc; the connection between any two adjacent external threads (1211) forms an external thread groove (1212), and the external thread groove (1212) is any one of a triangle, a trapezoid, or a circular arc; the connection between any two adjacent internal threads (1111) forms an internal thread groove (1112), and the internal thread groove (1112) is any one of a triangle, a trapezoid, or a circular arc.

11. The threaded connection assembly according to any one of claims 1 to 7, wherein, the external threaded connection member (12) comprises any one of a bolt, a screw, or a screw rod; the internal threaded connection member (11) comprises any one of a nut, a bolt sleeve, or a threaded hole structure.

12. A vane arrangement, characterized by comprising: a blade body (21), a blade root connection hole (212) being provided at a blade root joint circle (211) of the blade body (21); the threaded connection assembly according to any one of claims 1 to 11, being arranged in the blade root connection hole (212).

13. A wind power plant, characterized in that comprising: a main machine structure, a plurality of blades being rotatably arranged on the main machine structure; wherein at least one of the blades is the blade device according to claim 12.

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