CN219865802U - Connecting piece and fan - Google Patents

Abstract

The utility model relates to the field of connecting pieces, and provides a connecting piece and a fan, wherein the connecting piece is provided with a connecting thread, the difference value between the large diameter and the small diameter of each circle of screw teeth in the connecting thread is 2hi, the connecting thread at least comprises a circle of special screw teeth, the special screw teeth at least comprise a first circle of screw teeth, the height of the special screw teeth is him, hi is more than him, in a single circle of special screw teeth, the crests of the screw teeth are positioned on the same cylindrical surface, and the bottoms of the screw teeth are positioned on the same cylindrical surface. The connecting piece is meshed with the matching piece, and the height him of each circle of screw threads in the special screw threads is smaller than hi, so that a gap is formed between the special screw threads and the common screw threads, the meshing degree between the special screw threads and the common screw threads is reduced due to incomplete meshing, the stress at the positions of the special screw threads and the common screw threads is reduced, and the reliability of threaded connection is improved. The special screw thread comprises a first circle of screw thread, and can reduce the highest stress at the connecting piece and the matching piece.

Description

Connecting piece and fan

Technical Field

The utility model relates to the field of connecting pieces, in particular to a connecting piece and a fan, wherein the connecting piece comprises special threads.

Background

The threaded connection has the characteristics of simple structure, convenient assembly and disassembly and the like, and is widely applied to wind generating sets. The key parts of the wind generating set, such as a hub and a main shaft, a variable pitch bearing and a blade, are all connected through high-strength bolts. In the life cycle of the fan, the high-strength bolt also needs to bear severe limit and fatigue load, and is easy to fail. As shown in fig. 1, when the bolt 3' is connected with the nut 2', one ring of threads which are meshed with the nut 2' and are closest to the head 30' of the bolt 3' is a first ring of threads, and a second ring of threads, a third ring of threads and a fourth ring of threads … … are sequentially arranged from the first ring of threads towards the direction far away from the head of the bolt, specifically, a first ring of inner threads 21', a second ring of inner threads 22', a third ring of inner threads 23', a fourth ring of inner threads 24' are sequentially arranged on the nut, and a first ring of outer threads 31', a second ring of outer threads 32', a third ring of outer threads 33', and a fourth ring of outer threads 34' … … are sequentially arranged on the bolt; the first four circles of screw threads are generally larger in stress, namely the first circle of screw threads to the fourth circle of screw threads are larger in stress, wherein the stress at the first circle of screw threads is the largest, and the fracture of the high-strength bolt often occurs at the first circle of outer screw threads 31', because of larger stress concentration at the first circle of outer screw threads 31'. Therefore, the stress concentration at the first ring of outer screw teeth is reduced, and the method has great significance for improving the bearing capacity of the bolts and the operation reliability of the wind turbine generator system.

Disclosure of Invention

The utility model aims to overcome the defect of larger stress at the first ring of outer screw teeth on a connecting piece in the prior art, and provides the connecting piece and a fan.

The utility model solves the technical problems by the following technical scheme:

the connecting piece is provided with a connecting thread, the difference between the large diameter and the small diameter of each circle of threads in the connecting thread is 2hi, the connecting thread at least comprises one circle of special threads, the special threads at least comprise a first circle of threads, the heights of the circles of threads in the special threads are him, hi is more than him, in a single circle of special threads, the crests of the threads are positioned on the same cylindrical surface, and the bottoms of the threads are positioned on the same cylindrical surface.

In the technical scheme, the large diameter of the common inner screw teeth and the large diameter of the common outer screw teeth which are meshed with each other are the same, the small diameter is the same, and the heights of the screw teeth are the same; the connecting piece is meshed with the matching piece, the screw tooth height of the common screw tooth of the matching piece is hi, the screw tooth height of the special screw tooth is him < hi, after the special screw tooth is meshed with the common screw tooth, a gap is formed between the special screw tooth and the common screw tooth due to him < hi, the special screw tooth is not fully meshed with the common screw tooth, the meshing degree between the special screw tooth and the common screw tooth is reduced, so that the stress of the special screw tooth and the common screw tooth is reduced, and the reliability of threaded connection is improved. Because the stress at the first ring of threads is maximum, the special threads comprise the first ring of threads, and the stress at the first ring of outer threads and the first ring of inner threads can be effectively reduced, so that the highest stress at the threaded connection of the connecting piece and the matching piece is reduced. The crests of the threads in the single-circle special threads are positioned on the same cylindrical surface, the roots of the threads are positioned on the same cylindrical surface, and the single-circle special threads can be conveniently processed by cutting off the same height of each part of the single-circle common threads along the axial direction.

Preferably, the special screw thread at least comprises the first two turns of screw thread, and the difference between hi and him gradually becomes smaller along with the increase of the turns of the screw thread of the special screw thread.

In the technical scheme, the special screw thread at least comprises the first two circles of screw threads, along with the increase of the number of screw thread turns of the special screw thread, the difference value between hi and him is gradually reduced, on one hand, when the special screw thread is meshed with the common screw thread, the gap between the special screw thread and the common screw thread is gradually reduced along with the increase of the number of screw thread turns of the special screw thread, the meshing degree of the special screw thread and the common screw thread is improved, the stress of the first several circles of screw threads of the special screw thread is conveniently transferred to the position of the rear screw thread, namely, the stress corresponding to the first several circles of screw threads in the special screw thread is reduced, the stress of the position of the rear screw thread is improved, the stress of the meshing position between the connecting piece and the matching piece is stably changed, and the reliability of the screw thread connection is further improved. In two aspects, the processing and manufacturing of a plurality of special threads are also convenient. In the third aspect, the crests of the threads in the single circle of special threads are positioned on the same cylindrical surface, and the bottoms of the threads are positioned on the same cylindrical surface, so that the height of any circle of special threads can be independently adjusted.

Preferably, the special screw thread at least comprises the first four turns of screw threads.

In this technical scheme, because the stress of four rings of screw teeth department is biggest before the screw thread meshing is connected, special screw tooth includes four rings of screw teeth before, can guarantee that connecting piece and ordinary screw tooth are meshed the time overall stress is less, can also make the processing work load of connecting screw thread little simultaneously.

Preferably, the him corresponding to each circle of screw thread in the special screw thread is in an equi-differential sequence.

In the technical scheme, the heights of the special threads of each circle are changed in an arithmetic progression, so that the sizes of the threads of each circle in the special threads are changed stably, and the connection between the connecting piece and the matching piece is stable and reliable.

Preferably, 0.1 hi.ltoreq.him.ltoreq.0.9 hi.

Preferably, the him corresponding to the first round of screw thread is less than or equal to 0.3hi.

Preferably, the him corresponding to the last round of screw thread in the special screw thread is more than or equal to 0.9hi.

Preferably, the tooth shape of the connecting thread is triangular;

and/or the bottoms of the threads of each circle of the connecting thread are positioned on the same cylindrical surface.

In the technical scheme, the bottoms of all rings of threads of the connecting threads are positioned on the same cylindrical surface, so that the connecting threads of the connecting piece can be conveniently obtained by processing on the basis of standard threads, and the processing of the connecting piece is convenient.

Preferably, the connecting thread has an internal thread or an external thread.

A fan comprising a connector as claimed in any one of the preceding claims.

The utility model has the positive progress effects that:

the connecting piece is meshed with the matching piece, and the height him of each circle of screw teeth in the special screw teeth is smaller than 0.5 times of the difference value between the large diameter and the small diameter of the screw teeth, so that a gap is formed between the special screw teeth and the common screw teeth, the special screw teeth and the common screw teeth are not completely meshed, the meshing degree between the special screw teeth and the common screw teeth is reduced, the stress at the positions of the special screw teeth and the common screw teeth is reduced, and the reliability of threaded connection is improved. The special screw thread comprises a first ring of screw thread, so that the stress of the first ring of outer screw thread and the first ring of inner screw thread can be effectively reduced, and the highest stress of the threaded connection of the connecting piece and the matching piece is further reduced. The crests of the threads in the single-circle special threads are positioned on the same cylindrical surface, and the bottoms of the threads are positioned on the same cylindrical surface, so that the single-circle special threads can be conveniently processed.

Drawings

FIG. 1 is a schematic view of a prior art bolt and nut connection;

FIG. 2 is a schematic structural view of a connector according to an embodiment of the present utility model;

FIG. 3 is a schematic view of a structure of a connecting member and a common bolt connection according to an embodiment of the present utility model;

fig. 4 is a diagram of simulated data of the stress of a screw tooth of a connecting piece and a common bolt connected with a vs common nut and a common bolt according to an embodiment of the utility model.

Reference numerals illustrate:

the connecting piece 2, the first circle of inner screw threads 21, the second circle of inner screw threads 22, the third circle of inner screw threads 23, the fourth circle of inner screw threads 24 and the fifth circle of inner screw threads 25;

the bolt 3, the first outer screw thread 31, the second outer screw thread 32, the third outer screw thread 33, the fourth outer screw thread 34, the fifth outer screw thread 35, the sixth outer screw thread 36, the seventh outer screw thread 37, the eighth outer screw thread 38 and the ninth outer screw thread 39;

crest 41, root 42.

Detailed Description

The present utility model will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown.

In the present utility model, "normal … …" refers to "normal … …", and "normal bolt" refers to "standard bolt".

Fig. 2 to fig. 4 are schematic diagrams provided in this embodiment.

As shown in fig. 2, the connecting member 2 has a connecting thread, the connecting thread is an internal thread, the major diameter of each turn of thread in the connecting thread is D, the minor diameter is D, the difference between the major diameter and the minor diameter is D-d=2hi, the connecting thread includes a special thread and a common internal thread, and the thread height of the special thread is him, him < hi. Specifically, the special screw thread comprises the first four circles of screw threads, namely the special screw thread comprises a first circle of inner screw thread 21, a second circle of inner screw thread 22, a third circle of inner screw thread 23 and a fourth circle of inner screw thread 24, and the special screw thread is a common inner screw thread from a fifth circle of inner screw thread 25.

As shown in fig. 3, the connecting member 2 is engaged with the common bolt 3; the height of the outer screw thread of the common bolt 3, namely the common outer screw thread, is hi; the height of the screw thread of the special screw thread is him, and him is less than hi; after the special screw teeth are meshed with the outer screw teeth, because the him is smaller than the hi, gaps are formed between the special screw teeth and the outer screw teeth, the meshing degree between the special screw teeth and the outer screw teeth is reduced due to incomplete meshing, so that the stress at the positions of the special screw teeth and the outer screw teeth is reduced, and the reliability of threaded connection is improved. Because the stress at the first ring of threads is maximum, the special threads comprise the first ring of threads, and the stress at the first ring of outer threads 31 and the first ring of inner threads 21 can be effectively reduced, so that the highest stress at the threaded connection of the connecting piece 2 and the matching piece is reduced.

Because the stress of the first four turns of threads is the largest when the threads are engaged and connected, the special threads in the embodiment comprise the first four turns of threads, the overall stress is smaller when the connecting piece 2 is engaged with the outer threads, and meanwhile, the processing workload of the connecting threads is small. In other embodiments, a particular thread may include only a first turn of thread, and may include the first two, three, four, five or more turns of thread.

As shown in fig. 2, in the single-turn special screw thread, the crests 41 of the screw thread are positioned on the same cylindrical surface, and the roots 42 of the screw thread are positioned on the same cylindrical surface, so that the processing of the single-turn special screw thread is facilitated. Specifically, on the basis of a circle of common internal screw teeth, the same heights of all the crests are cut off along the axial direction to obtain new crests, namely a circle of special screw teeth.

Further, as shown in fig. 2, the bottoms of the threads of each circle on the connecting piece are all located on the same cylindrical surface, and the first four circles of special threads are processed on the basis of the standard internal threads, so that the connecting threads can be obtained, and the processing of the connecting piece 2 is simple and convenient.

As shown in fig. 2, the inner diameter of each ring of thread in the special thread is dim, the height of thread is him=d/2-dim/2, m=1, 2, 3, 4, and as the number of turns m of the special thread increases, dim becomes smaller gradually, so that him becomes larger gradually. As shown in fig. 3, as the number of turns m of the special screw thread increases, the him gradually increases, so that the gap between the special screw thread and the outer screw thread gradually decreases, the engagement degree of the special screw thread and the outer screw thread is gradually improved, the stress of the screw thread of the first several turns of the connecting screw thread is conveniently transferred to the screw thread of the later, namely, the stress corresponding to the screw thread of the first several turns of the connecting screw thread is reduced, the stress of the screw thread of the later is improved, the stress of the engagement position between the connecting piece 2 and the common bolt 3 is smoothly changed along with the increase of the number of turns of the screw thread, and the reliability of the screw thread connection is further improved. On the other hand, the processing and manufacturing of a plurality of special threads are also convenient.

As shown in fig. 3:

when m=1, the height him=hi1=d/2-di 1/2=0.3 hi of the first ring of inner thread 21;

m=2, the height of the second ring of inner threads 22, him=hi2=d/2-di 2/2=0.5 hi;

when m=3, the height him=hi3=d/2-di 3/2=0.7 hi of the third internal thread 23;

at m=4, the height of the fourth internal thread 24 is him=hi4=d/2-di 4/2=0.9 hi.

In this embodiment, as the number of turns of the thread of the special thread increases, the difference between hi and him becomes smaller gradually, and in a single turn of the special thread, the crests 41 of the threads are located on the same cylindrical surface, the roots 42 of the threads are located on the same cylindrical surface, and thus the height of each turn of special thread can be flexibly adjusted. For example, after the first four turns of inner thread are machined, the height of any one turn of special thread can be independently adjusted at this time, for example, the height of the third turn of inner thread 23 is adjusted from 0.7hi to 0.6hi, and other turns of special thread cannot be affected.

In this embodiment, the height him of each ring of threads in the special threads is as follows: 0.1hi is less than or equal to him is less than or equal to 0.9hi; the height him of the special screw thread is less than or equal to 0.9hi, so that the problem that the screw thread of the special screw thread is too small in height and inconvenient to process can be avoided; the height him of the special screw thread is more than or equal to 0.1hi, and the inconvenience of processing due to too small difference between the inner diameter and the small diameter of the special screw thread can be avoided. In other embodiments, the height of the special screw thread may also be less than 0.1hi, or greater than 0.9hi.

In this embodiment, the height hi1=0.3 hi of the first ring of inner threads 21. In other embodiments, the height hi1 of the first ring of inner threads 21 may be greater than, less than, or equal to 0.3hi; when hi1 is less than or equal to 0.3hi, the difference between the inner diameter and the small diameter of the first ring of inner screw threads 21 can be larger, so that the second ring of inner screw threads 22 or more rings of inner screw threads can be conveniently arranged as special screw threads.

In the present embodiment, the height hi4=0.9 hi of the last round of threads among the special threads, i.e., the fourth round of inner threads 24. In other embodiments, the height him of the last turn of thread in a particular thread may be greater than, less than, or equal to 0.9hi; when hi4 is more than or equal to 0.9hi, the difference between the inner diameter and the small diameter of the last round of screw teeth in the special screw teeth is smaller, so that the screw tooth heights of the last round of screw teeth in the special screw teeth and the common inner screw teeth can be changed stably, and the connection between the connecting piece 2 and the bolt 3 is stable and reliable.

In this embodiment, the heights of the special threads of each circle are 0.3hi, 0.5hi, 0.7hi and 0.9hi in sequence, which are in an equal-difference array, so that the heights of the threads of each circle in the special threads can be changed smoothly, and the connection between the connecting piece 2 and the bolt 3 is stable and reliable. In other embodiments, the heights of the individual turns of the special screw thread may be in an equal array.

In this embodiment, the thread form of the connecting thread of the connecting member 2 is triangular, and the special thread is formed by cutting out a part of the normal female thread. In other embodiments, the connector 2 may also be 3D printed or otherwise machined.

In this embodiment, the minor diameter D of each thread of the connecting thread is constant, and the major diameter D of each thread is also constant, so that the connecting thread has a simple structure and is convenient to process. In other embodiments, the minor and major diameters of each thread of the connecting thread may vary with the number of turns of the thread; accordingly, the major and minor diameters of the mating member engaged with the connecting threads are also changed in accordance with the change in the major and minor diameters of the connecting threads to effect engagement of the connecting member 2 with the mating member.

In other embodiments, the thread form of the connecting thread is triangular, the bottoms of the threads of each circle in the connecting thread are positioned on the same cylindrical surface, and the two schemes can be adopted simultaneously or only one of the two schemes can be adopted.

As shown in fig. 4, the first set of data is the stress of the screw thread on the common bolt 3 when the common nut is connected with the common bolt 3, and the second set of data is the stress of the screw thread on the common bolt 3 when the connecting piece 2 with the special screw thread is connected with the common bolt 3. The common bolts 3 in the two groups of data are completely consistent and screwed into nine circles of outer screw threads, namely, the first circle of outer screw threads 31 to the ninth circle of outer screw threads 39 (see figure 3); compared with the connecting piece 2, the common nut is identical with the connecting piece 2 except that the connecting piece 2 is provided with special threads; the working conditions are consistent. As can be seen from fig. 4, when the connecting piece 2 with special screw threads is engaged with the common bolt 3, for the outer screw threads of the common bolt 3, the stress at the first circle of outer screw threads 31 can be effectively reduced, so that the highest stress of the outer screw threads is reduced by 26.4%; the stress of the outer screw teeth of the first several circles is effectively transferred to the outer screw teeth of the back, so that the stress of the outer screw teeth of each circle is more balanced and more stable. Specifically, in this embodiment, the first four turns of threads adopt special threads, so that the stress of the first turn of outer threads 31 and the second turn of outer threads 32 is reduced, and the stress of the third turn of outer threads 33, the fourth turn of outer threads 34, the fifth turn of outer threads 35, the sixth turn of outer threads 36, the seventh turn of outer threads 37, the eighth turn of outer threads 38 and the ninth turn of outer threads 39 is increased.

In this embodiment, the common bolt 3 is engaged with the internal thread of the connecting piece 2, and in other embodiments, other mating pieces with external threads are engaged with the connecting piece 2.

In this embodiment, the connecting thread has an internal thread, the special thread is a special internal thread, and the special internal thread is engaged with the normal bolt 3 having an external thread. In other embodiments, the connection threads may have external threads, with the special threads being special external threads that engage with a mating member having internal threads.

The connecting piece 2 provided by the embodiment can be applied to a fan for generating electricity, and the connecting piece 2 is used for realizing connection between fan parts. There is a lot of literature on how to apply the connection 2 in fans, reference being made in particular to the prior art.

In this embodiment, the special screw thread of the connecting piece 2 is a special inner screw thread, and is meshed with the common bolt 3, and only the special inner screw thread is required to be machined from any opening end of the connecting piece 2. In other embodiments, the special screw thread of the connecting piece 2 is a special external screw thread, and is meshed with the common internal screw thread, and when the special external screw thread is processed, the pretightening force of the connecting piece 2 after being installed needs to be considered, that is, the number of turns of the screw thread of the connecting piece 2 screwed into the common internal screw thread needs to be considered. Therefore, the special screw thread is a special inner screw thread, and the design and processing of the connecting piece 2 can be simpler compared with the special screw thread is a special outer screw thread.

While specific embodiments of the utility model have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the utility model is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the utility model, but such changes and modifications fall within the scope of the utility model.

Claims (10)

1. The connecting piece is provided with a connecting thread, the difference value between the large diameter and the small diameter of each circle of threads in the connecting thread is 2hi, and the connecting piece is characterized in that the connecting thread at least comprises one circle of special threads, the special threads at least comprise a first circle of threads, the heights of the circles of threads in the special threads are him, hi is more than him, in a single circle of special threads, the crests of the threads are located on the same cylindrical surface, and the bottoms of the threads are located on the same cylindrical surface.

2. The connector of claim 1, wherein the special thread comprises at least two first turns of threads, and the difference between hi and him becomes smaller as the number of turns of the special thread increases.

3. The connector of claim 2, wherein the special screw thread comprises at least the first four turns of screw threads.

4. A connector according to claim 3, wherein the him of each turn of thread in the particular thread varies in an arithmetic progression.

5. The connector of claim 2, wherein 0.1hi is less than or equal to him is less than or equal to 0.9hi.

6. The connector of claim 2 or 5, wherein the first turn of threads corresponds to a him of 0.3hi or less.

7. The connector of claim 2 or 5, wherein the last thread turn of the special thread corresponds to a him not less than 0.9hi.

8. The connector of claim 1, wherein the profile of the connecting threads is triangular;

and/or the bottoms of the threads of each circle of the connecting thread are positioned on the same cylindrical surface.

9. The connector of claim 1, wherein the connecting threads have internal or external threads.

10. A fan comprising a connector according to any one of claims 1-9.