Method for preventing dropped bolts after breakage and bolt fastening structure

Abstract

The application discloses a method for preventing the falling of fractured studs and a stud fastening connection structure, and relates to the field of bolt connection, which comprises at least two studs, the studs are threadedly connected with fastening nuts, and one end of the stud is threadedly connected with a lock nut after sequentially penetrating through a pre-tightening elastic piece and a connecting piece; there are at least two studs penetrating through the same connecting piece; the studs are connected through the connecting piece, and the pre-tightening elastic piece and the lock nut are matched to make the fractured stud keep connected with the connecting piece; after the fracture of one or more studs, the other studs can fix the fractured stud through the connecting piece. The application effectively prevents the falling of the fractured stud into a rotating part such as a wheel hub, avoids the damage of the fractured stud to the parts of the unit and the secondary disasters caused by the safety crisis of the unit.

Description

Technical Field

[0001] This invention relates to the field of bolted connections, and in particular to a method for preventing studs from breaking and falling off, and a stud fastening connection structure. Background Technology

[0002] Studs (such as double-ended studs) are widely used in the connection between wind turbine hubs and motor flanges, and between hubs and main shaft flanges. Stud breakage is a common problem in the wind power industry. For studs (such as double-ended studs) installed on rotating flanges, breakage can cause them to fall into rotating components such as the hub, damaging internal parts and even affecting the turbine's pitch control, posing a threat to turbine safety. To address this issue, a method and a stud fastening connection structure to prevent stud breakage and subsequent fall are proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a method and a stud fastening connection structure to prevent broken studs from falling into rotating components such as wheel hubs, thereby avoiding damage to unit parts and secondary disasters that could endanger unit safety caused by broken studs.

[0004] The technical solution adopted in this invention is as follows: A method for preventing a stud from falling off after breakage, wherein the stud is connected to a fastening nut; comprising the following steps:

[0005] S1: After the stud is connected to the fastening nut, the pre-tightening elastic element, the connecting plate and the anti-loosening nut are sequentially assembled on the stud; among them, the connecting plate has multiple connecting holes, and different studs pass through different connecting holes;

[0006] S2: The movable connecting piece, the pre-tightening elastic element deforms and has elastic force, which acts on the fastening nut and the connecting piece;

[0007] S3: Tighten the anti-loosening nut to lock the position of the connecting piece. The connecting piece and the fastening nut constrain the pre-tightened elastic element to maintain its deformed state.

[0008] S4: If one or more studs break, the fastening nut is subjected to the elastic force of the pre-tightening elastic element, and the fastening nut and the broken stud remain in a pre-tightened state, and the fastening nut and the stud remain connected.

[0009] S5: The broken stud remains through the connecting hole, and the other unbroken studs are constrained by the connecting piece, so the broken stud will not fall out.

[0010] A stud fastening connection structure includes at least two studs, each stud being threadedly connected to a fastening nut, and one end of each stud passing through a pre-tightening elastic element and a connecting piece in sequence before being threadedly connected to an anti-loosening nut; at least two studs pass through the same connecting piece.

[0011] Furthermore, the connecting piece has at least two connecting holes, the relative positions of which match the relative distribution positions of the multiple studs.

[0012] Furthermore, the connecting piece has two connecting holes, and the relative positions of the two connecting holes match the relative positions of two adjacent studs.

[0013] Furthermore, the connecting piece has at least a first connecting piece and a second connecting piece model. One end of the first connecting piece and the second connecting piece has an overlapping portion with a matching shape, and the other end of the first connecting piece and the second connecting piece is a non-overlapping portion. Both the overlapping portion and the non-overlapping portion have connecting holes.

[0014] Furthermore, it also includes an intermediate connecting piece, the two ends of which are overlapping portions.

[0015] Furthermore, the pre-tightening elastic element is a compression spring.

[0016] Furthermore, the connecting piece is provided with a boss, and the anti-loosening nut is provided with a stop that matches the size of the boss.

[0017] Furthermore, the stop is evenly distributed along the circumference of the lock nut.

[0018] Furthermore, the cross-section of the boss is set as a right trapezoid or a right triangle, and the upward direction of the inclined surface of the right trapezoid or right triangle is the same as the direction of rotation of the stud.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. This invention connects various studs through connecting plates, and with the cooperation of pre-tightening elastic elements and anti-loosening nuts, the broken studs are kept connected to the connecting plates; after one or more studs break, the other studs can be fixed by the connecting plates, effectively preventing the broken studs from falling into rotating parts such as wheel hubs, avoiding the broken studs from damaging unit parts and causing secondary disasters that endanger the safety of the unit.

[0021] 2. The present invention utilizes the elastic force generated by the deformation of the pre-tightening elastic element to ensure that the fastening nut and the stud remain in a pre-tightened state after the stud breaks, preventing the fastening nut from falling off the stud. Furthermore, this elastic force acts on the anti-loosening nut after passing through the connecting piece, improving the stability of the threaded connection between the anti-loosening nut and the stud. This effectively ensures the stability of the connecting piece in the broken stud, providing a basis for preventing the stud from falling into the rotating parts. Attached Figure Description

[0022] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is an exploded view of the stud fastening connection structure disclosed in this invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the stud fastening connection structure disclosed in this invention;

[0025] Figure 3 This is a schematic diagram of the anti-loosening nut disclosed in this invention;

[0026] Figure 4 This is a schematic diagram of the structure of the first connecting piece disclosed in this invention;

[0027] Figure 5 This is a schematic diagram of the structure of the intermediate connecting piece disclosed in this invention;

[0028] Figure 6 This is a schematic diagram of the structure of the second connecting piece disclosed in this invention;

[0029] Markings in the diagram: 1-Stud; 2-Fastening nut; 3-Preload elastic element; 4-Connecting piece; 41-Boss; 42-First connecting piece; 43-Intermediate connecting piece; 44-Second connecting piece; 45-Overlapping part; 46-Non-overlapping part; 47-Connecting hole; 5-Anti-loosening nut; 51-Stop; 6-Flange. Detailed Implementation

[0030] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0031] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0032] Example 1

[0033] like Figures 1-6As shown, a method to prevent studs from falling off after breakage is described. The stud 1 is connected to a fastening nut 2. Taking a double-ended stud locking flange 6 as an example, the double-ended stud passes through the flange 6 holes on two flanges 6. In one embodiment, both ends of the double-ended stud are connected to fastening nuts 2, and the two fastening nuts 2 press against the corresponding flange 6 end faces, thereby locking the flange 6. In another embodiment, one of the flanges has a blind hole; one end of the double-ended stud passes through this blind hole and connects to the fastening nut 2, while the other end passes through the other flange and connects to the fastening nut 2, locking the two flanges. The location where the stud 1 breaks is usually between the two flanges 6, that is, between the two parts to be locked. For ease of explanation, a single-sided structure of the double-ended stud is used as an example, hereinafter referred to as stud 1. The method includes the following steps:

[0034] S1: After the stud 1 is connected to the fastening nut 2, and the fastening nut 2 closes the locking flange 6, the pre-tightening elastic element 3, the connecting piece 4 and the anti-loosening nut 5 are sequentially assembled on the stud 1; the connecting piece 4 has multiple connecting holes 47, and different studs 1 pass through different connecting holes 47. After the stud 1 breaks, it is ensured that there are other studs 1 to fix the connecting piece 4, thereby fixing the broken stud 1.

[0035] S2: The movable connecting piece 4 and the pre-tightening elastic element 3 deform and have elastic force, which acts on the fastening nut 2 and the connecting piece 4; in this step, the force of the movable connecting piece 4 can come from an external force or from the thrust provided by the rotation of the anti-loosening nut 5 in step S3.

[0036] It should be noted that there are two implementation methods regarding the moving direction of the connecting piece 4:

[0037] In the first embodiment, if the pre-tightening elastic element 3 is a compression elastic element, then from the middle of the stud 1 to the end of the stud 1, the sequence is flange 6, fastening nut 2, pre-tightening elastic element 3, connecting piece 4, and anti-loosening nut 5; when moving the connecting piece 4, the connecting piece 4 is moved towards the fastening nut 2, pressing the pre-tightening elastic element 3, thereby compressing the pre-tightening elastic element 3 to have elastic force, which will act on the fastening nut 2 and through the connecting piece 4 on the anti-loosening nut 5.

[0038] In the second embodiment, if the pre-tightening elastic element 3 is a tension elastic element, then from the middle of the stud 1 to the end of the stud 1, the sequence is flange 6, fastening nut 2, pre-tightening elastic element 3, anti-loosening nut 5, and connecting piece 4; the two ends of the pre-tightening elastic element 3 are respectively connected to the fastening nut 2 and the connecting piece 4; when the connecting piece 4 is moved, the connecting piece 4 is moved away from the fastening nut 2, stretching the pre-tightening elastic element 3, so that the pre-tightening elastic element 3 is stretched and has elastic force, which will act on the fastening nut 2 and through the connecting piece 4 on the anti-loosening nut 5.

[0039] In both of the above embodiments, the elastic force acting on the fastening nut 2 is as follows: Without elastic force, after the stud 1 breaks, the thread preload between the fastening nut 2 and the stud will disappear. However, in this embodiment, due to the presence of the preload elastic element 3, the elastic force of the preload elastic element 3 acts on the fastening nut 2. After the stud 1 breaks, the fastening nut 2 maintains the preload state with the stud 1 under the action of the elastic force, thus preventing the fastening nut from falling off the stud.

[0040] In both of the above embodiments, the elastic force acts on the anti-loosening nut 5 through the connecting piece 4, as follows: The anti-loosening nut 5 itself has anti-loosening capability, such as a nylon nut; the elastic force further improves the stability of the anti-loosening nut 5 connected to the stud 1, effectively ensuring that the anti-loosening nut 5 itself, as well as the connecting piece 4 and the pre-tightening elastic element 3, will not loosen and fall off during device operation, preventing damage to device components and secondary disasters.

[0041] Furthermore, in the second embodiment, due to the restriction of the connecting piece 4 by the other studs 1, the fastening nut 2 is extremely inconvenient to rotate during installation. Therefore, the first embodiment is preferred in this example. The first embodiment will be further described below.

[0042] S3: Tighten the anti-loosening nut 5. The anti-loosening nut 5 moves closer to the fastening nut 2, locking the distance between the connecting piece 4 and the fastening nut 2. The connecting piece 4 and the fastening nut 2 constrain the pre-tightened elastic element 3 to maintain its deformed state.

[0043] S4: If one or more studs 1 break, the fastening nut 2 is subjected to the elastic force of the pre-tightening elastic element 3, the fastening nut 2 and the broken stud 1 remain in a pre-tightened state, the fastening nut 2 and the stud 1 remain connected, and the connecting piece 4 is continuously constrained between the fastening nut 2 and the anti-loosening nut 5.

[0044] S5: If the broken stud 1 remains through the connecting hole 47, and the other unbroken studs 1 are still fixed to the connecting piece 4, then the connecting piece 4 constrains the broken stud 1, and the broken stud 1 will not fall off.

[0045] Example 2

[0046] like Figures 1-6 As shown, a stud fastening connection structure, using a method described in Embodiment 1 to prevent studs 1 from breaking and falling, includes at least two studs 1. In fact, multiple studs 1 need to be assembled along the circumference of the flange 6 to fasten the flange 6; the studs 1 are threadedly connected to fastening nuts 2, and one end of the stud 1 passes through the pre-tightening elastic element 3 and the connecting piece 4 in sequence before being threadedly connected to the anti-loosening nut 5; there are at least two studs 1 passing through the same connecting piece 4.

[0047] The anti-loosening nut 5 locks the position of the pre-tightening elastic element 3, preventing it from loosening. Like a nylon nut, this effectively ensures that the anti-loosening nut 5, connecting piece 4, and pre-tightening elastic element 3 will not loosen or fall during operation, preventing damage to equipment components and secondary disasters. The pre-tightening elastic element 3 has deformation properties, thus possessing elastic force. Even after the stud 1 breaks, this elastic force ensures that the fastening nut 2 and stud 1 still have pre-tightening force, maintaining their connection. Thus, the connecting piece 4 remains connected to the broken stud 1. This allows other unbroken studs 1 to be secured by the connecting piece 4, effectively preventing the broken stud 1 from falling into rotating components like wheel hubs, thus avoiding damage to unit components and secondary disasters that could endanger unit safety.

[0048] Example 3

[0049] Based on Example 2, further feasible specific implementation methods are proposed.

[0050] In one feasible implementation, the connecting piece 4 is provided with at least two connecting holes 47, and the relative positions of the connecting holes 47 match the relative distribution positions of the multiple studs 1, that is, different connecting holes 47 are passed through by different studs 1; multiple connecting holes 47 ensure the stability of preventing broken studs 1 from falling into the rotating part, and even if multiple studs 1 break, broken studs 1 can be prevented from falling into the rotating part.

[0051] It should be noted that for the connection of flange 6, the connecting piece 4 can be a whole ring structure, with connecting holes 47 corresponding to the positions of the holes in flange 6; or the connecting piece 4 can be multiple pieces, which can be assembled into a ring structure.

[0052] In one feasible implementation, for the above-described implementation, the more holes opened on the same connecting piece 4, the higher the positional deviation requirement and the more precise the processing accuracy; however, the actual solution disclosed in this invention does not require processing accuracy; to simplify the processing of the connecting piece 4, such as Figures 4-6 As shown, the connecting piece 4 has two connecting holes 47. The relative positions of the two connecting holes 47 match the relative positions of two adjacent studs 1. The connecting piece 4 connects the adjacent studs 1.

[0053] Furthermore, in the embodiment where only two connecting holes 47 are provided on the connecting piece 4, there is a possibility that adjacent studs 1 may break; therefore, as Figures 1-5As shown, the connecting piece 4 has at least two types: a first connecting piece 42 and a second connecting piece 44. One end of the first connecting piece 42 and the second connecting piece 44 has a matching overlapping portion 45, and the other end of the first connecting piece 42 and the second connecting piece 44 is a non-overlapping portion 46. Two connecting holes 47 are respectively opened on the overlapping portion 45 and the non-overlapping portion 46, so that the same stud 1 passes through the connecting holes 47 on different connecting pieces 4, thereby realizing the end-to-end connection of all connecting pieces 4, increasing the amount of mutually constrained studs 1, and thus ensuring the stability of preventing broken studs 1 from falling into the rotating part.

[0054] Furthermore, in the above embodiments, such as Figures 1-6 As shown, even with the presence of the first connecting piece 42 and the second connecting piece 44, only three adjacent studs 1 can be connected simultaneously. To further increase the number of interconnected studs 1, an intermediate connecting piece 43 is also included. Both ends of the intermediate connecting piece 43 are overlapping portions 45. The overlapping portions 45 of the intermediate connecting piece 43 can overlap with the overlapping portions 45 of the first connecting piece 42, the second connecting piece 44, and the adjacent intermediate connecting pieces 43. Thus, the number of intermediate connecting pieces 43 can be adjusted according to the actual number of studs 1 to achieve the purpose of connecting all studs 1 into a whole for constraint, ensuring stability and preventing broken studs 1 from falling into the rotating parts.

[0055] The thickness of the overlapping portion 45 after overlapping is the same as the thickness of the non-overlapping portion 46; if the thickness of the overlapping portion 45 is half that of the non-overlapping portion 46, the thickness of the overlapping portion 45 of the first connecting piece 42 and the second connecting piece 44 after overlapping is equal to that of the non-overlapping portion 46.

[0056] Example 4

[0057] Based on any one of the implementation methods in Examples 2-3, further feasible specific implementation methods are proposed.

[0058] In one feasible implementation, the pre-tightening elastic element 3 is a compression spring, matching the pre-tightening elastic element 3 in Embodiment 1 as a compression elastic element.

[0059] In one feasible implementation, as mentioned above, the stability of the position of the anti-loosening nut 5 is crucial. This is to prevent the anti-loosening nut 5, along with the connecting piece 4 and the pre-tightening elastic element 3, from detaching from the stud 1 and being carried into the device, damaging components and causing secondary disasters. Therefore, it is necessary to further improve the positional stability of the anti-loosening nut 5. To this end, a boss 41 is provided on the connecting piece 4, and a corresponding stop 51 matching the size of the boss 41 is provided on the anti-loosening nut 5. After assembly, the boss 41 can be embedded in the stop 51. With the boss 41 on the connecting piece 4 and constrained by the other studs 1, the boss 41 will not rotate. Thus, the boss 41 restricts the stop 51, thereby restricting the anti-loosening nut 5 from rotating around the axis of the stud 1, improving the connection stability between the anti-loosening nut 5 and the stud 1, and preventing the anti-loosening nut 5, the connecting piece 4, and the pre-tightening elastic element 3 from detaching from the stud 1.

[0060] It should be noted that the assembly of the boss 41 and the stop 51 has strong stability under the action of the pre-tightening elastic element 3. That is, the elastic force makes the connecting piece 4 and the anti-loosening nut 5 fit tightly, thereby preventing the boss 41 from disengaging from the stop 51.

[0061] Furthermore, the stop 51 is evenly distributed along the circumference of the anti-loosening nut 5 to ensure uniform force distribution.

[0062] It should be noted that the stop 51 is distributed on the anti-loosening nut 5, and the boss 41 should also be evenly distributed around the connecting hole 47; for the connecting piece 4, the boss 41 is always set on the outer side of the connecting piece 4; the outer side of the connecting piece 4 is the side of the connecting piece 4 that is away from the fastening nut 2 after installation.

[0063] One feasible implementation method is, for example Figures 4-6 As shown, the cross-section of the boss 41 is set as a right trapezoid or a right triangle, and the base of the right trapezoid or the side of the right triangle is fixed on the connecting piece 4; the upward direction of the inclined surface of the right trapezoid or the right triangle is the same as the rotation direction of the stud 1; when the anti-loosening nut 5 is screwed in, the stop 51 can move along the inclined surface and push the pre-tightening elastic member 3 to make way for the movement of the stop 51; when the anti-loosening nut 5 is screwed out, the stop 51 is restricted by the right angle side of the boss 41, and the anti-loosening nut 5 cannot be screwed out, ensuring the stability of the anti-loosening.

[0064] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A stud fastening connection structure, characterized in that: It includes at least two studs (1), studs (1) are threadedly connected to fastening nuts (2), and one end of studs (1) passes through a pre-tightening elastic element (3) and a connecting piece (4) in sequence and is threadedly connected to a lock nut (5); there are at least two studs (1) passing through the same connecting piece (4). The connecting piece (4) has two connecting holes (47), and the relative positions of the two connecting holes (47) match the relative positions of the two adjacent studs (1). The connecting piece (4) has at least two types: a first connecting piece (42) and a second connecting piece (44). One end of the first connecting piece (42) and the second connecting piece (44) has an overlapping part (45) with matching shape, and the other end of the first connecting piece (42) and the second connecting piece (44) is a non-overlapping part (46). Both the overlapping part (45) and the non-overlapping part (46) have connecting holes (47).

2. The stud fastening connection structure according to claim 1, characterized in that: The connecting piece (4) has at least two connecting holes (47), and the relative positions of the connecting holes (47) match the relative distribution positions of the multiple studs (1).

3. The stud fastening connection structure according to claim 1, characterized in that: The connecting piece (4) also includes an intermediate connecting piece (43), both ends of which are overlapping portions (45).

4. The stud (1) fastening connection structure according to any one of claims 1-3, characterized in that: The pre-tightening elastic element (3) is a compression spring.

5. The stud fastening connection structure according to claim 1, characterized in that: The connecting piece (4) is provided with a boss (41), and the anti-loosening nut (5) is provided with a stop (51) that matches the size of the boss (41).

6. The stud fastening connection structure according to claim 5, characterized in that: The stop (51) is evenly distributed along the circumference of the anti-loosening nut (5).

7. The stud fastening connection structure according to claim 5, characterized in that: The cross section of the boss (41) is set as a right trapezoid or a right triangle, and the upward direction of the inclined surface of the right trapezoid or right triangle is the same as the rotation direction of the stud (1).

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