Lock nut

Abstract

The application discloses a lock nut, and relates to the technical field of nuts, which comprises a main nut, a tension cylinder fixed on the top of the main nut, the inner diameter of the tension cylinder being the same as that of the main nut, and a main thread being arranged on the circumferential inner wall of the tension cylinder and the main nut; a secondary nut, the inner diameter of the secondary nut being the same as that of the main nut, a tension ring groove being arranged on the bottom of the circumferential inner wall of the secondary nut, and the tension ring groove being used for inserting the tension cylinder; a secondary thread being arranged on the circumferential outer wall of the tension cylinder, a tension thread being arranged on the circumferential inner wall of the tension ring groove, and the tension thread being matched with the secondary thread; the main thread is also arranged on the circumferential inner wall of the secondary nut; and the lead of the main thread is different from that of the tension thread. The application has the effect of improving the self-locking property and service life of the lock nut.

Description

Technical Field

[0001] This application relates to the technical field of nuts, and in particular to a locking nut. Background Technology

[0002] Currently, anti-loosening nuts on the market are mainly divided into three categories: Compression-type locknuts: Some compression-type locknuts achieve their anti-loosening function by pressing against the mounting surface with annularly distributed teeth at the end. After tightening, reversing the nut will generate greater friction from the teeth than rotating it forward. However, compression-type locknuts, whether single or double nuts, cannot eliminate the clearance between the nut and the screw. When leaving the base surface, the self-tightening force of the nut due to the clearance between the screw and the lock will be greatly reduced.

[0003] Glue-injected lock nuts: These lock nuts are generally not reused, resulting in a low reuse rate.

[0004] Tensioner-type locknuts: Because achieving tension requires a special threaded mating structure, they suffer from complex structure and manufacturing difficulties, and the synchronization of the mating threads is also poor. In addition, the low friction between the threads results in poor self-locking force, thus limiting the anti-loosening effect and the number of times they can be reused.

[0005] Anti-loosening nuts commonly used in mining, rail transportation, and vehicle manufacturing can be broadly categorized into the following improvement methods: For example, CN95240473.7 - a composite self-locking screw, which uses a double helix on the screw and two nuts in conjunction with it - the screw thread is easily damaged, and due to the intersection of the double helixes, the nut is prone to jamming when loosened; For example, CN202222719365.2 - a self-locking nut assembly, which uses two nuts with tapered steps in conjunction, and locking is achieved by making multiple contraction seams on the nuts with raised steps, which is difficult to manufacture and has poor self-tightening force; For example, CN202080088766.3 - an eccentric anti-loosening nut disclosed in the anti-loosening device - because it uses the eccentric principle, it has a large shear force on the screw, and the radial thrust is limited when the locking force is large, resulting in a reduced anti-loosening effect.

[0006] Therefore, the key challenge in developing anti-loosening nuts is how to produce them in large quantities at low cost, with strong self-locking ability and the ability to be reused multiple times. Summary of the Invention

[0007] In order to improve the shortcomings of existing anti-loosening nuts, such as complex structure, high manufacturing cost, poor self-locking force and difficulty in repeated use, this application provides an anti-loosening nut.

[0008] The anti-loosening nut provided in this application adopts the following technical solution: A lock nut, comprising The main nut has a tensioning cylinder fixed at the top. The inner diameter of the tensioning cylinder is the same as the inner diameter of the main nut. The tensioning cylinder and the main nut have main threads on their circumferential inner walls. The auxiliary nut has the same inner diameter as the main nut, and a tensioning ring groove is provided at the bottom of the circumferential inner wall for the tensioning cylinder to be inserted into. The outer circumferential wall of the tensioning cylinder is provided with auxiliary threads, and the inner circumferential wall of the tensioning ring groove is provided with tensioning threads, which are engaged with the auxiliary threads. The main threads are also distributed on the circumferential inner wall of the secondary nut; The lead of the main thread and the tension thread are different.

[0009] By adopting the above technical solution, the tensioning cylinder is threaded into the tensioning ring groove, combining the main nut and the auxiliary nut. Finally, the main nut and auxiliary nut are threaded together onto the corresponding installation position on the screw. Then, only the auxiliary nut is rotated. Due to the different leads of the main thread and the tensioning thread, while the auxiliary thread and the tensioning thread rotate and lock together, the main thread also locks the screw thread, thus achieving self-locking after nut installation. This makes operation more convenient and enables low-cost mass production. Since the auxiliary nut can only be removed from the screw after rotating to its position relative to the main nut before rotation, a stable anti-loosening effect is achieved.

[0010] Optionally, the main thread direction is the same as the tension thread direction.

[0011] By adopting the above technical solution, when the main nut needs to be locked, only the secondary nut needs to be rotated in the same direction. With the continued rotation of the secondary nut, the main nut is pulled upward by the interaction of the tension thread and the secondary thread, thereby achieving a tensioning anti-loosening effect and reducing the fit clearance between the main thread and the screw thread.

[0012] Optionally, the helix angles of the main thread and the tension thread are the same.

[0013] By adopting the above technical solution, since the main thread and the tightening thread have the same helix angle but different radii, their pitches are also different. When both are single threads, the tightening thread has a larger pitch. Therefore, after the main nut is tightened differently, during the rotation of the secondary nut relative to the main nut, the secondary nut moves downward relative to the bolt, while the main nut moves upward relative to the secondary nut, thus forming a mutual tightening relationship between the main nut and the secondary nut. Since the helix is ​​the difference in lead between the main thread and the tightening thread, the tightening force of the secondary nut on the main nut is much greater than the reaction force of the main nut relative to the bolt, resulting in a better self-locking effect. Furthermore, the contact state between the secondary thread and the tightening thread, and the contact state between the main thread and the screw, can maintain stable surface contact, increasing the contact area and thus improving the locking and anti-loosening effect. On the other hand, it can also further reduce the clearance between the main thread and the screw thread.

[0014] Optionally, the outer diameter of the auxiliary thread is d1, and the nominal diameter of the main nut is DN, where d1 ≥ 1.5DN.

[0015] By adopting the above technical solution, the thickness of the stretching cylinder is limited, thereby effectively ensuring the strength of the stretching cylinder.

[0016] Optionally, the height of the tensioning cylinder is h1, and the height of the main nut is h2, where h1 ≥ (1 / 3)h2.

[0017] By adopting the above technical solution, the height setting of the tensioning cylinder can effectively increase the mating area of ​​the tensioning thread and the auxiliary thread, thereby improving the stability of the locking of the main nut and the auxiliary nut.

[0018] Optionally, the farthest distance from the outer circumferential wall of the main nut to its own central axis is the same as the farthest distance from the outer circumferential wall of the secondary nut to its own central axis.

[0019] By adopting the above technical solution, the main nut and the auxiliary nut can be installed together with tools such as nut sleeves or calipers while maintaining parallel sidewalls, thus improving the installation efficiency of anti-loosening nuts.

[0020] Optionally, the main nut has a marking groove engraved on its circumferential outer wall, and the marking groove is also engraved on the circumferential outer wall of the secondary nut; The loading and unloading position is when the main nut and the auxiliary nut are rotated together to a position where they can be installed on the same screw. When the two marking slots are facing each other, the side walls where the marking slots are located are parallel to each other. The auxiliary nut is threaded onto the main nut from this position. After the auxiliary nut is rotated to the bottom and abuts against the top of the main nut, it is rotated in the opposite direction to the position where the two marking slots are facing each other. At this time, the main nut and the auxiliary nut are in the loading and unloading position, and the distance between the main nut and the auxiliary nut is c.

[0021] By adopting the above technical solution, the marking groove can provide a positional reference for the installation and removal positions of the main nut and the auxiliary nut, thereby improving the installation efficiency of the anti-loosening nut.

[0022] Optionally, the number of threads in the tension thread must be at least two.

[0023] By adopting the above technical solution, the tightening thread plays a key self-locking and anti-loosening role. Increasing the number of threads in the tightening thread can effectively increase the contact area between the tightening thread and the auxiliary thread, increase the friction between the threads, and also increase the service life of the tightening thread, thereby increasing the axial force that the tightening thread can withstand.

[0024] Optionally, when the main nut and the auxiliary nut are in the loading / unloading position, the same retaining plate is inserted into the marking slot. When the main nut and the auxiliary nut rotate relative to each other, the retaining plate will be twisted off.

[0025] By adopting the above technical solution, the clamping plate effectively fixes the mounting and dismounting positions of the main nut and the auxiliary nut, facilitating their installation on the screw. When anti-loosening self-tightening is required, rotation of the auxiliary nut will break the clamping plate without affecting its normal rotation.

[0026] Optionally, the card plate is engraved with multiple dividing slots, and the distance between adjacent dividing slots is c.

[0027] By adopting the above technical solution, the partition groove can be used to determine the loading and unloading positions of the main nut and the auxiliary nut, so as to facilitate the removal of the main nut and the auxiliary nut from the screw. When the marking grooves are opposite and the distance between the marking grooves is the distance between two adjacent partition grooves, the main nut and the auxiliary nut can be removed together. The clamping plate can also be moved down to be located in both marking grooves at the same time, so as to fix the relative position of the main nut and the auxiliary nut at this time.

[0028] In summary, this application includes at least one of the following beneficial technical effects: By setting the helix angle and direction of rotation of the main thread and the tightening thread to be equal, the rotation trajectories of the main thread and the tightening thread are parallel when they are in a combined state and rotate relative to each other on the same screw, reducing thread clearance. Due to the difference in lead, the helix amount is the difference in lead between the main thread and the tightening thread, so that the pull generated by the tightening thread when tightening locks the reaction force of the main thread on the main nut against the screw, which has better self-locking performance. Moreover, the threads are in a surface contact state, which effectively increases the contact area, thereby improving the friction and locking effect during self-locking and achieving flexible self-locking. Because the parameters of the main thread and the tightening thread are different, the main nut and the auxiliary nut will pass through several loading and unloading positions during the installation and rotation process. Therefore, the marking groove can make it easy to find the loading and unloading position, so as to facilitate the installation and removal of the anti-loosening nut on the screw. The partition groove can be used as a reference to easily find the deepest loading and unloading position of the tensioning cylinder in the tensioning ring groove. This position is the loading and unloading position with the greatest stability and self-locking force after locking after the main nut and auxiliary nut are combined. The clamping plate can also be used multiple times on the nut. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application; Figure 2 This is a cross-sectional view of Embodiment 1 of this application; Figure 3 This is a cross-sectional view showing parameter information in Embodiment 1 of this application; Figure 4 This is a cross-sectional view of Embodiment 2 of this application showing that the tension thread is a double thread line; Figure 5 This is a schematic diagram of the structure of Embodiment 3 of this application; Figure 6 This is Example 3 of this application. Figure 5 Section A shows an enlarged view of the dividing groove; Figure 7 This is a schematic diagram of the structure of Embodiment 3 of this application, showing the main nut and the auxiliary nut in a locked state.

[0030] In the diagram, 1 is the main nut; 11 is the main thread; 12 is the marking groove; 2 is the auxiliary nut; 21 is the tension ring groove; 211 is the tension thread; 3 is the tension cylinder; 31 is the auxiliary thread; 4 is the clamping plate; and 41 is the dividing groove. Detailed Implementation

[0031] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0032] This application discloses an anti-loosening nut. Example

[0033] refer to Figure 1 and Figure 2 The anti-loosening nut includes a main nut 1 and a secondary nut 2. A tensioning cylinder 3 is fixed to the top of the main nut 1. The inner diameter of the tensioning cylinder 3 is the same as that of the main nut 1, and their central axes are collinear. The tensioning cylinder 3 and the main nut 1 have main threads 11 on their circumferential inner walls. The secondary nut 2 has the same inner diameter as the main nut 1, and its circumferential inner wall has a tensioning ring groove 21 at its bottom for the tensioning cylinder 3 to be inserted into. When the tensioning cylinder 3 is located within the tensioning ring groove 21, the central axis of the secondary nut 2 is collinear with the central axis of the main nut 1. The tensioning cylinder 3 has secondary threads 31 distributed on its circumferential outer wall, and the tensioning ring groove 21 has tensioning threads 211 distributed on its circumferential inner wall. The tensioning threads 211 and the secondary threads 31 cooperate with each other. The main threads 11 are also distributed on the circumferential inner wall of the secondary nut 2.

[0034] The main thread 11 is used to mate with the threaded part on the screw to which it is installed. In this embodiment, the main thread 11 and the tensioning thread 211 also need to meet the following conditions: 1. The direction of rotation of the main thread 11 is the same as that of the tension thread 211.

[0035] 2. The helix angles of the main thread 11 and the tension thread 211 are the same.

[0036] In this embodiment, the farthest distance from the outer wall of the main nut 1 to its own central axis and the farthest distance from the outer wall of the secondary nut 2 to its own central axis are the same, both being hexagonal nuts.

[0037] In use, the main nut 1 and the auxiliary nut 2 are installed by threading the tensioning cylinder 3 into the tensioning ring groove 21. To facilitate the installation and use of the anti-loosening nut, before installation, the main nut 1 and the auxiliary nut 2 are rotated until their corresponding circumferential sidewalls are parallel. This allows the main nut 1 and the auxiliary nut 2 to be fitted together by the nut installation sleeve tool, and also makes it easier for the main nut 1 and the auxiliary nut 2 to be clamped together by the same caliper on their circumferential sidewalls. This facilitates the rotation of the main nut 1 and the auxiliary nut 2 together, allowing them to be easily installed on the same screw.

[0038] After the bottom end of the main nut 1 is pressed against the mounting face of the bolt, maintaining the same direction of rotation, only the auxiliary nut 2 rotates. Since the main thread 11 and the tightening thread 211 have the same direction of rotation, the auxiliary nut 2, upon rotation, shortens the distance to the main nut 1, pulling the main nut 1 upwards. Because the main thread 11 and the tightening thread 211 have the same helix angle but different radii, the pitch of the main thread 11 is smaller than the pitch of the tightening thread 211. This causes the pull generated by the tightening thread 211 during tightening to lock the reaction force of the main thread 11 on the main nut 1 against the bolt. Because the helix is ​​the difference in lead between the main thread 11 and the tightening thread 211, the pulling force of the auxiliary nut 2 on the main nut 1 is much greater than the reaction force of the main nut 1 relative to the bolt, resulting in better self-locking. The rotation trajectories of the two thread lines of the main thread 11 and the tightening thread 211 are parallel and have different leads, allowing for a larger pressing area between the tightening thread 211 and the auxiliary thread 31 after tightening. Similarly, the main thread 11 and the screw thread also have a larger clamping area, resulting in a greater locking force. Because the effective contact area of ​​the thread is larger during locking, the thread can withstand a greater preload, and the service life of the lock nut will also be increased.

[0039] refer to Figure 3 The outer diameter of the auxiliary thread 31 is d1, and the nominal diameter of the main nut 1 is DN; the height of the tensioning cylinder 3 is h1, and the height of the main nut 1 is h2. Therefore, the anti-loosening nut needs to further meet the following requirements: d1≥1.5DN; h1 ≥ (1 / 3)h2.

[0040] Based on the above formulas, the height and thickness of the tensioning cylinder 3 are correspondingly limited, ensuring that the tensioning cylinder 3 has a suitable thickness and increasing the range of forces it can withstand. The height setting of the tensioning cylinder 3 determines the coverage area and depth of the tensioning thread 211, ensuring that when the tensioning thread 211 and the auxiliary thread 31 are locked together, the most basic contact area and thread strength are met.

[0041] refer to Figure 3 Both the bottom of the circumferential outer wall of the main nut 1 and the top of the circumferential outer wall of the auxiliary nut 2 are engraved with marking grooves 12, meaning that there is only one marking groove 12 on each of the main nut 1 and the auxiliary nut 2. The assembly position is when the main nut 1 and the auxiliary nut 2 are rotated to a position where they can be mounted on the same screw. There is at least one assembly position for the main nut 1 and the auxiliary nut 2. When the two marking grooves 12 are facing each other, the side walls containing the marking grooves 12 are also parallel to each other. The auxiliary nut 2 is threaded onto the main nut 1 from this position. After the auxiliary nut 2 rotates to its bottommost position and abuts against the top of the main nut 1, it is rotated in the opposite direction to the position where the two marking grooves 12 are facing each other. This position is the closest assembly position for the main nut 1 and the auxiliary nut 2, and the distance between the main nut 1 and the auxiliary nut 2 at this time is c.

[0042] During the machining of the main nut 1 and the auxiliary nut 2, the auxiliary thread 31 and the tightening thread 211 are machined first, followed by the machining of the marking groove 12. When the main nut 1 and the auxiliary nut 2 are rotated to a position of distance c, the two marking grooves 12 are opposite each other and the sidewalls of the main nut 1 and the auxiliary nut 2 are parallel to each other. After the main nut 1 and the auxiliary nut 2 are fixed together, the main thread 11 is machined on the main nut 1 and the auxiliary nut 2 together. This allows the main nut 1 and the auxiliary nut 2 to be installed on the same screw when the distance is c and the marking lines are aligned. The marking groove 12 also effectively facilitates the identification of the relative position of the main nut 1 and the auxiliary nut 2, realizes the disassembly of the anti-loosening nut, and improves the efficiency of installing and disassembling the main nut 1 and the auxiliary nut 2 on the same screw.

[0043] The implementation principle of Embodiment 1 of this application is as follows: The main nut 1 and the auxiliary nut 2 are rotated relative to each other from the positions where the two marking grooves 12 are opposite, so that the tensioning cylinder 3 is threadedly connected to the tensioning ring groove 21. After the auxiliary nut 2 rotates to the position where it abuts against the main nut 1, it is rotated in the opposite direction to the position where the two marking grooves are opposite. Using a matching hex socket or calipers, the main nut 1 and auxiliary nut 2 are threadedly installed on the corresponding screw in this state, and the main nut 1 is pressed against the mounting surface. Then, only the auxiliary nut 2 continues to rotate, causing it to continue rotating downwards. Because the helix angle of the main thread 11 and the tensioning thread 211 is the same, the leads of the main thread 11 and the tensioning thread 211 are different. Therefore, a nut self-locking state occurs where the main thread 11 abuts against the screw thread, and the auxiliary thread 31 abuts against the tensioning thread 211. Furthermore, since the helix angles of the main thread 11 and the tightening thread 211 are the same, when the anti-loosening nut in this embodiment is in a self-locking state, the effective contact area between the threads will be larger, approaching a surface contact state, thereby obtaining greater friction and force-bearing area, increasing the maximum torque that the threads can withstand, reducing the probability of thread damage, and achieving synchronicity and flexible self-locking between the threads.

[0044] The marking groove not only facilitates the simultaneous installation of the main nut 1 and the auxiliary nut 2, but also facilitates their simultaneous disassembly, enabling multiple uses. Example

[0045] refer to Figure 4 The difference between Embodiment 2 and Embodiment 1 is that the tension thread 211 has at least two threads, and in this embodiment, it has two. Increasing the number of threads in the tension thread 211 ensures that the auxiliary thread 31 also maintains the same number of threads as the tension thread 211. This increase in the number of threads leads to an increase in the effective contact area of ​​the threads when the nut is tightened, further improving the self-locking property of the threads. Additionally, increasing the number of helical threads reduces the thread depth, thereby effectively enhancing the strength of both the auxiliary thread and the tension thread. Example

[0046] refer to Figure 5 and Figure 6 The difference between this embodiment and Embodiment 1 is that when the two marking slots 12 of the main nut 1 and the auxiliary nut 2 are opposite each other, the same retaining plate 4 can be inserted. The material of the retaining plate 4 can be broken when the main nut 1 and the auxiliary nut 2 rotate relative to each other. The material of the retaining plate 4 can be wood, plastic, etc., and in this embodiment it is plastic. In normal use, when the main nut 1 and the auxiliary nut 2 are combined and located at the loading / unloading position where the distance between the main nut 1 and the auxiliary nut 2 is c, the length of the retaining plate 4 is the same as the farthest distance between the two marking slots 12. The retaining plate 4 is engraved with multiple dividing slots, and the distance between adjacent dividing slots is c. Figure 7When the card plate 4 breaks, it breaks at the dividing groove.

[0047] The implementation principle of Embodiment 3 differs from that of Embodiment 1 in that, after removing the clamping plate 4, the distance between the main nut 1 and the secondary nut 2 can be measured through the dividing groove to determine whether it is 'c', thus finding the most stable loading and unloading position before locking. Subsequently, the clamping plate 4 can be inserted into the marking groove 12 to fix the positions of the main nut 1 and the secondary nut 2 together, facilitating transportation and direct use. The clamping plate 4 breaks when the main nut 1 and the secondary nut 2 rotate relative to each other, and also breaks at the dividing groove. After the clamping plate 4 breaks, the remaining clamping plate 4 can still be used.

[0048] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A locking nut, characterized in that: include The main nut (1) has a tensioning cylinder (3) fixed on top. The inner diameter of the tensioning cylinder (3) is the same as the inner diameter of the main nut (1). The tensioning cylinder (3) and the main nut (1) have a main thread (11) on their circumferential inner walls. The auxiliary nut (2) has the same inner diameter as the main nut (1), and a tensioning ring groove (21) is provided at the bottom of the circumferential inner wall. The tensioning ring groove (21) is used for the tensioning cylinder (3) to be inserted into. The outer wall of the tensioning cylinder (3) is provided with auxiliary threads (31), and the inner wall of the tensioning ring groove (21) is provided with tensioning threads (211). The tensioning threads (211) are engaged with the auxiliary threads (31). The main thread (11) is also distributed on the circumferential inner wall of the secondary nut (2); The lead of the main thread (11) and the tension thread (211) are different.

2. The anti-loosening nut according to claim 1, characterized in that: The direction of rotation of the main thread (11) is the same as that of the tension thread (211).

3. The anti-loosening nut according to claim 1, characterized in that: The main thread (11) and the tension thread (211) have the same helix angle.

4. The anti-loosening nut according to claim 3, characterized in that: The outer diameter of the auxiliary thread (31) is d1, and the nominal diameter of the main nut (1) is DN, where d1 ≥ 1.5DN.

5. The anti-loosening nut according to claim 3, characterized in that: The height of the tension cylinder (3) is h1, and the height of the main nut (1) is h2, h1≥(1 / 3)h2.

6. The anti-loosening nut according to claim 1, characterized in that: The farthest distance from the outer circumferential wall of the main nut (1) to its own central axis is the same as the farthest distance from the outer circumferential wall of the secondary nut (2) to its own central axis.

7. The anti-loosening nut according to claim 1, characterized in that: The main nut (1) has a marking groove (12) engraved on its circumferential outer wall, and the marking groove (12) is also engraved on the circumferential outer wall of the secondary nut (2); The loading and unloading position is when the main nut (1) and the auxiliary nut (2) are rotated together to a position where they can be installed on the same screw. When the two marking slots are opposite each other, the side walls where the marking slots are located are parallel to each other. The secondary nut (2) is threaded onto the main nut (1) from this position. After the secondary nut (2) rotates to the bottom and abuts against the top of the main nut (1), it rotates in the opposite direction to the position where the two marking slots (12) are opposite each other. At this time, the main nut (1) and the secondary nut (2) are in the loading and unloading position, and the distance between the main nut (1) and the secondary nut (2) is c.

8. The anti-loosening nut according to claim 1, characterized in that: The tension thread (211) has at least 2 threads.

9. A locking nut according to claim 8, characterized in that: When the main nut (1) and the secondary nut (2) are in the loading and unloading position, the same card plate (4) is inserted in the marking groove (12). When the main nut (1) and the secondary nut (2) rotate relative to each other, the card plate (4) will be twisted off.

10. A locking nut according to claim 9, characterized in that: The card plate (4) has multiple dividing grooves engraved on it, and the distance between adjacent dividing grooves is c.

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