A lock nut and device containing a lock nut

Abstract

The utility model belongs to the technical field of fastener, specifically relates to a locknut and device containing locknut, the utility model provides a locknut including coaxial integral flange and hexagon nut body, the inner wall of nut body is equipped with internal thread, its free end away from flange is equipped with at least three axial pressure points, axial pressure point is formed through axial local extrusion, makes nearby internal thread plastic deformation, preferably three 120 degree interval is equipped with in free end hexagonal vertex angle, the diameter of flange is greater than nut body, and the end face can select anti -skid line. The locknut effect can be adjusted, is durable, and assembly does not need accessory or solidification, adapts conventional tool and standard thread, and the torque difference is small and can be reused. The device containing the locknut realizes part fixed connection through cooperation with external thread connecting piece.

Description

Technical Field

[0001] This utility model belongs to the field of fastener technology, specifically relating to an anti-loosening nut and a device containing the anti-loosening nut. Background Technology

[0002] In fields such as machinery manufacturing, automotive industry, aerospace, wind power equipment, and rail transportation, threaded connections are a widely used basic connection method for fixing components and transmitting force. Locknuts, as a safety barrier for threaded connections, directly determine the stability of the connection structure and the safety of equipment operation. From suspension connectors in automobile chassis and bolt fixings in engine blocks to flange connections in wind turbine towers and bogie assemblies in rail transit vehicles, locknuts play a crucial role in preventing loosening. Once a threaded connection loosens due to vibration, impact, temperature changes, or other operating conditions, it can lead to component displacement and abnormal equipment noise, or even structural failure and major safety accidents. Therefore, the reliability of locknuts in preventing loosening, ease of assembly, and adaptability to operating conditions have always been core requirements for industry research and development.

[0003] As industrial equipment develops towards higher loads, more complex operating conditions, and longer lifespans, the market demands increasingly stringent performance requirements for anti-loosening nuts. Although existing anti-loosening technologies have formed various technical routes, they still have significant limitations in practical applications, making it difficult to simultaneously meet the comprehensive needs of excellent anti-loosening effect, efficient assembly, strong adaptability, and reusability.

[0004] Common mechanical anti-loosening methods include locking clips, cotter pins, and wire mesh anti-loosening. These methods require additional anti-loosening accessories. During assembly, the nut must be tightened first, and then the accessories must be installed, such as locking clip positioning, cotter pin drilling, and wire mesh winding. The steps are cumbersome and require high operational precision. Taking wire mesh winding as an example, it requires aligning multiple threaded holes, which significantly reduces assembly efficiency. At the same time, these accessories are mostly for single use, and new accessories must be replaced after disassembly, increasing maintenance costs.

[0005] Adhesive-based anti-loosening methods involve applying anaerobic adhesives or other bonding agents to the thread surface, utilizing the adhesive's bonding strength after curing. However, this method presents two major problems: First, it requires the adhesive to fully cure before achieving the anti-loosening effect, typically taking several hours to tens of hours to reach the expected loosening torque. This makes it unsuitable for rapid, continuous assembly, especially in vibrating operating environments. Second, the cured adhesive tightly bonds the nut and bolt, requiring forceful damage to the threads or heating to dissolve the adhesive during disassembly. This not only damages the thread structure but also makes the nut difficult to reuse. Furthermore, the adhesive's performance is susceptible to temperature and humidity fluctuations; for example, it softens and fails at high temperatures, compromising the durability of the anti-loosening effect.

[0006] Some anti-loosening nuts achieve anti-loosening through structural design, such as double nuts. When using them, the two nuts need to be tightened one after the other, and the preload between the two nuts is used to prevent loosening. However, the difference in tightening torque between the two nuts needs to be controlled during assembly, which is complicated to operate and difficult to assemble.

[0007] In summary, providing a lock nut that offers stable and excellent anti-loosening performance, requires no additional anti-loosening accessories, has simple and efficient assembly steps, and is compatible with industry-standard assembly tools and standard threads is of great significance for meeting the safety and efficiency requirements of threaded connections in various fields. Utility Model Content

[0008] In view of the shortcomings of the existing technology, this utility model provides an anti-loosening nut and a device containing the anti-loosening nut.

[0009] This utility model provides an anti-loosening nut, including a flange and a nut body that are coaxially arranged and integrally connected. The inner wall of the nut body is machined with internal threads. At least three axial pressure points are provided on the free end face of the nut body away from the flange. The axial pressure points are formed by axial local extrusion and plastic deformation of the internal threads near the axial pressure points.

[0010] As a further optimization, the number of axial pressure points is three, and they are evenly distributed at 120° intervals along the circumference of the nut body.

[0011] As a further optimization, the cross-section of the nut body is hexagonal, and the axial pressing point is set at the apex of the hexagonal outer contour of the free end face.

[0012] As a further optimization scheme, the pressure point depth H of the axial pressure point satisfies: Max(0.1,0.125d-0.9)≤H≤Max(0.3,0.25d-1.5), where d is the nominal diameter of the anti-loosening nut.

[0013] As a further optimization scheme, the pressure point area S of the axial pressure point satisfies: 1.1d-4.5≤S≤1.5d-3, where d is the nominal diameter of the anti-loosening nut.

[0014] As a further optimization, the diameter of the flange is larger than the maximum circumscribed circle diameter of the nut body.

[0015] As a further optimization plan,

[0016] When the nominal diameter of the lock nut is M5, the axial pressure point depth H ranges from 0.1mm to 0.3mm, and the pressure point area S ranges from 1mm². 2 ~3mm 2 ;

[0017] When the nominal diameter of the lock nut is M6, the axial pressure point depth H ranges from 0.1mm to 0.3mm, and the pressure point area S ranges from 3mm². 2 ~6mm 2 ;

[0018] When the nominal diameter of the lock nut is M8, the axial pressure point depth H ranges from 0.1mm to 0.5mm, and the pressure point area S ranges from 5mm². 2 ~8mm 2 ;

[0019] When the nominal diameter of the lock nut is M10, the axial pressure point depth H ranges from 0.4mm to 1.0mm, and the pressure point area S ranges from 7mm². 2 ~11mm 2 ;

[0020] When the nominal diameter of the lock nut is M12, the axial pressure point depth H ranges from 0.6mm to 1.5mm, and the pressure point area S ranges from 9mm². 2 ~15mm 2 .

[0021] As a further optimization, the material of the locknut is preferably a metal material, including steel, aluminum or copper.

[0022] As a further optimization, the flange has radially extending anti-slip grooves on the side face away from the nut body.

[0023] This utility model also provides a device containing an anti-loosening nut, including an external threaded connector, a connected part, and the aforementioned anti-loosening nut; the outer wall of the external threaded connector is provided with a standard external thread, and the internal thread of the anti-loosening nut mates with the standard external thread of the external threaded connector to realize the threaded connection between the external threaded connector and the connected part; the standard external thread of the external threaded connector passes through the connected part, and the end face of the flange away from the nut body is in contact with the surface of the connected part.

[0024] Beneficial effects

[0025] This utility model of anti-loosening nut offers excellent anti-loosening performance, which can be adjusted as needed. It also boasts good anti-loosening durability and can be reused a limited number of times under normal working conditions. The assembly process requires no additional anti-loosening accessories or waiting for adhesive to cure; the assembly steps are identical to those of ordinary nuts, significantly improving installation efficiency. Furthermore, this anti-loosening nut is compatible with industry-standard assembly tools and standard threads, meeting basic connection requirements. The small difference between tightening and loosening torque avoids operational difficulties caused by excessive torque during assembly while ensuring stable anti-loosening performance. It demonstrates comprehensive advantages in terms of adaptability to working conditions, ease of operation, and reliability in preventing loosening. Attached Figure Description

[0026] Figure 1 and Figure 2 This is a three-dimensional schematic diagram of the anti-loosening nut of this utility model.

[0027] Figure 3 This is a top view of the anti-loosening nut of this utility model.

[0028] In the diagram, 1 is the flange; 2 is the nut body; 3 is the internal thread; and 4 is the axial pressure point. Detailed Implementation

[0029] The present invention is further illustrated by the following embodiments, which are intended to more clearly illustrate the technical solution of the present invention, and should not be construed as a limitation.

[0030] like Figures 1 to 3 As shown, the anti-loosening nut is an integrated structure, mainly consisting of a flange 1 and a hexagonal nut body 2. It is preferably made of metal materials such as steel, aluminum, and copper, but is not limited to metal materials.

[0031] Flange 1 and nut body 2 are coaxially arranged and integrally connected. The diameter of flange 1 is larger than the maximum outer diameter of nut body 2. Flange 1 can distribute the pressure on the surface of the connected parts when the anti-loosening nut is tightened, and prevent the connected parts from being deformed or damaged due to excessive local pressure.

[0032] In some embodiments, the end face of the flange 1 facing away from the nut body 2 can be a flat end face (as shown in the figure). In other preferred embodiments, the end face of the flange 1 facing away from the nut body 2 can also be provided with radially extending anti-slip textures to increase the static friction between the flange and the surface of the connected parts, further suppressing radial displacement after the nut is tightened, and helping to improve the anti-loosening effect.

[0033] The nut body 2 has a standard hexagonal cross-section, compatible with conventional wrenches such as open-end wrenches and box wrenches, facilitating clamping and tightening during assembly and conforming to industry-standard assembly tools. The inner wall of the nut body 2 is machined with internal threads 3. The thread profile, pitch, and other parameters of the internal threads 3 also meet the requirements of conventional threaded connections and can be matched with the standard external threads to be mated, thus achieving basic connection functionality.

[0034] Three axial pressure points 4 are provided on the end (free end face) of the nut body 2 away from the flange 1, causing deformation of the internal thread 3 near the axial pressure points 4. These three axial pressure points 4 are evenly distributed at 120° intervals along the circumference of the nut body 2. The axial pressure points 4 are recessed relative to the end face of the nut body 2, and this recessed structure can only be formed by axial local extrusion and cannot be formed by cutting (such as drilling or milling). During the axial local extrusion process, the metal material undergoes plastic flow due to external force, which directly causes changes in the pitch and / or tooth profile of the internal thread 3 in the area corresponding to and near the axial pressure points 4. This thread deformation can form significant torsional resistance when matched with normal external threads, thereby achieving the anti-loosening function. Furthermore, the degree of thread deformation can be adjusted by controlling parameters such as extrusion depth and extrusion area, thereby controlling the magnitude of the anti-loosening torque. If the axial pressure point 4 is formed by cutting, the processing method is essentially to remove local material from the end of the nut body 2, rather than to cause the material to undergo plastic deformation. Therefore, it cannot cause the internal thread 3 near the end of the nut body 2 to produce the same thread deformation, and cannot achieve the same anti-loosening effect.

[0035] When assembly is required, align the internal thread 3 of the lock nut with the external thread of the component to be connected. Use a standard wrench to hold the hexagonal nut body 2 and turn the wrench in the tightening direction until the end face of the flange 1 facing away from the nut body 2 is completely in contact with the surface of the component to be connected, and the tightening torque reaches the design requirements for that part. This will achieve a stable anti-loosening effect. Therefore, compared to existing anti-loosening measures such as locking plates, steel wires, cotter pins, and thread-locking adhesives, this lock nut requires no additional accessories or waiting for adhesive to cure. The assembly steps are the same as for ordinary nuts, significantly improving installation efficiency.

[0036] In some preferred embodiments, the three axial pressure points 4 on the free end face of the nut body 2 are located at three vertices spaced apart from each other among the six vertices of the hexagonal end face (as shown in the figure). The radial thickness of the material is greatest at the vertices of the hexagonal outer contour of the free end face. During the axial extrusion molding process, the material at this location can provide more sufficient plastic flow space and structural support, resulting in the optimal stability of the axial pressure points 4. During the tightening of the anti-loosening nut with the external thread and subsequent use, the extruded deformation part of the internal thread 3 will continuously bear a large external force, which tends to restore the deformed part to its original shape. If the stability of the axial pressure points 4 is insufficient, this correction phenomenon will be more significant, resulting in a weakening of the torsional resistance during thread engagement, which is not conducive to maintaining a stable anti-loosening effect in the long term. However, the axial pressure points 4 located at the vertices, with their structural rigidity provided by the material thickness, counteract this correction trend, improve the durability of the anti-loosening effect, and after multiple disassemblies, the plastic deformation of the internal thread 3 can still be well maintained. Under normal working conditions, it can be reused 3-5 times.

[0037] It should be noted that if the axial pressure point 4 is replaced by the midpoint of three spaced edges among the six edges of the hexagonal end face, a good anti-loosening effect can also be achieved. However, the radial thickness of the material at the midpoint of the edge is smaller, and the structural stability of the axial pressure point 4 after extrusion is far inferior to that of the vertex setting method. After multiple cycles of tightening and loosening, the deformation of the internal thread 3 generated by the axial pressure point 4 at the midpoint of the edge is even more unstable, resulting in a certain degree of decrease in anti-loosening resistance.

[0038] Furthermore, the depth and area of ​​the axial pressure point 4 have a significant impact on the anti-loosening effect, and the optimal ranges for pressure point depth and area are as follows:

[0039] The range of the pressure point depth H (unit: mm) is: Max(0.1, 0.125d-0.9)≤H≤Max(0.3, 0.25d-1.5);

[0040] The area of ​​the pressure point S (unit: mm) 2 The range of ) is: 1.1-4.5≤S≤1.5d-3;

[0041] Where d is the nominal diameter of the lock nut (unit: mm).

[0042] Furthermore, for anti-loosening nuts with nominal diameters of M5, M6, M8, M10, and M12, the preferred range of pressure point depth and pressure point area is shown in Table 1.

[0043] Table 1. Range of pressure point parameters for locknuts of different nominal diameters.

[0044] 5(M5) 0.1～0.3 1～3 6(M6) 0.1～0.3 3～6 8(M8) 0.1～0.5 5～8 10(M10) 0.4～1.0 7～11 12(M12) 0.6～1.5 9～15

[0045] The following tests will examine the tightening and loosening torques of lock nuts of different specifications. The specific test plan and results are as follows:

[0046] All anti-loosening nuts used in the test adopted a uniform structural form and were made of 304 stainless steel. The three axial pressure points 4 on the free end face of the nut body 2 were set at three vertices spaced apart from each other among the six vertices of its hexagonal end face. During the test, anti-loosening nuts of the corresponding specifications in Table 2 were selected first. According to the pressure point depth and pressure point area parameters set in Table 2, a mold with raised pressure points was used to press three axial pressure points 4 distributed at 120° intervals on the free end face of the nut body 2. Then, each finished nut was assembled with a matching standard external thread bolt (same specification and same pitch). The test environment was set to normal temperature (25℃±2℃) and normal pressure.

[0047] During the test, a digital torque testing machine was used to clamp the nut body and slowly twist it in the standard tightening direction. The maximum torque required to overcome the thread resistance during the first tightening process (i.e., the first tightening torque) was recorded. After tightening, the assembly was left to stand for 24 hours. Then, the nut was rotated in the opposite direction to disassemble it, and the torque required to overcome the anti-loosening resistance during the first unscrewing process (i.e., the first unscrewing torque) was recorded.

[0048] Five samples were tested for each parameter combination. If abnormal data was found during the test, the abnormal data was removed first, and then the corresponding number of samples were added to make up the effective sample size. Finally, the average value of all effective data was listed in Table 2.

[0049] Table 2 Torque Test Results

[0050]

[0051] According to the torque test results in Table 2, under the same nominal specification, the anti-loosening effect can be adjusted by the pressure point parameters. For example, for M6 nuts, the pressure point depth increases from 0.1mm to 0.3mm, and the pressure point area increases from 3mm² to 4mm². 2 Expanded to 6mm 2 The initial tightening torque increases from 0.51 Nm to 0.85 Nm, and the untightening torque increases from 0.48 Nm to 0.83 Nm, showing a clear upward trend. Therefore, the pressure point parameters can be adjusted according to different working conditions to match the required anti-loosening resistance. These anti-loosening nuts have a large anti-loosening torque. For example, as the nominal diameter increases from M6 to M12, the maximum tightening torque increases from 0.85 Nm to 4.31 Nm, and the maximum untightening torque increases from 0.83 Nm to 3.34 Nm, meeting the requirements of larger-sized connectors for higher anti-loosening torque. Furthermore, the initial untightening torque of each nut size remains high, with a small difference from the corresponding tightening torque. This avoids operational difficulties caused by excessive tightening torque during assembly and provides stable torsional resistance through the plastic deformation of the internal thread, ensuring the anti-loosening effect. Combined with the characteristics of requiring no additional anti-loosening accessories and having the same assembly steps as ordinary nuts, it exhibits significant comprehensive advantages in anti-loosening performance, operational efficiency, and adaptability to working conditions.

[0052] The above embodiments are exemplary and are intended to illustrate the technical concept and features of this utility model, so that those skilled in the art can understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A locking nut, characterized in that, It includes a flange (1) and a nut body (2) that are coaxially arranged and integrally connected. The inner wall of the nut body (2) is machined with an internal thread (3). At least three axial pressure points (4) are provided on the free end face of the nut body (2) away from the flange (1). The axial pressure points (4) are formed by axial local extrusion and the internal thread (3) near the axial pressure points (4) undergoes plastic deformation.

2. The anti-loosening nut according to claim 1, characterized in that, The number of axial pressure points (4) is three, and they are evenly distributed at 120° intervals along the circumference of the nut body (2).

3. The anti-loosening nut according to claim 2, characterized in that, The cross-section of the nut body (2) is hexagonal, and the axial pressing point (4) is located at the apex of the hexagonal outer contour of the free end face.

4. The anti-loosening nut according to claim 3, characterized in that, The pressure point depth H of the axial pressure point (4) satisfies: Max(0.1,0.125d-0.9)≤H≤Max(0.3,0.25d-1.5), where d is the nominal diameter of the anti-loosening nut; where the unit of pressure point depth H is mm; and the unit of nominal diameter d is mm.

5. The anti-loosening nut according to claim 3, characterized in that, The pressure point area S of the axial pressure point (4) satisfies: 1.1d-4.5≤S≤1.5d-3, where d is the nominal diameter of the anti-loosening nut; where the unit of pressure point area S is mm²; and the unit of nominal diameter d is mm.

6. The anti-loosening nut according to any one of claims 1-5, characterized in that, The diameter of the flange (1) is greater than the maximum circumscribed circle diameter of the nut body (2).

7. The anti-loosening nut according to claim 6, characterized in that, The anti-loosening nut is made of a metal material, including steel, aluminum, or copper.

8. The anti-loosening nut according to claim 6, characterized in that, The flange (1) has radially extending anti-slip texture on the side face away from the nut body (2).

9. A device containing an anti-loosening nut, characterized in that, It includes an external threaded connector, a connected part, and a locking nut as described in any one of claims 1-8; the outer wall of the external threaded connector is provided with a standard external thread, and the internal thread (3) of the locking nut is engaged with the standard external thread of the external threaded connector to realize the threaded connection between the external threaded connector and the connected part; the standard external thread of the external threaded connector passes through the connected part, and the end face of the flange (1) facing away from the nut body (2) is in contact with the surface of the connected part.

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