A slotted lock nut

Abstract

This invention belongs to the field of fastener technology, specifically relating to a grooved anti-loosening nut, comprising a nut body and a threaded hole provided on the nut body. At least one end of the nut body is provided with a wedge-shaped portion and a groove, the tip of the wedge-shaped portion being the axial end of the nut body, and at least part of the groove being located at the end of the wedge-shaped portion. The grooved anti-loosening nut provided in this application utilizes the synergistic effect of the wedge-shaped portion and the groove. The tip of the wedge-shaped portion first contacts the surface of the fastener, generating a strong radial engagement force under axial pressure. Simultaneously, the surface material of the fastener undergoes plastic deformation under extrusion pressure and embeds into the groove located at the end of the wedge-shaped portion, forming a reliable mechanical locking barrier. This effectively prevents the nut from rotating and loosening due to vibration, significantly improving the reliability of anti-loosening. Furthermore, it has a simple structure, requires no additional accessories, and is easy to install and disassemble, while maintaining the versatility of the nut, suitable for fastening needs under various vibration conditions.

Description

Technical Field

[0001] This invention belongs to the field of fastener technology, specifically relating to a grooved anti-loosening nut. Background Technology

[0002] In modern industry, the anti-loosening performance of fasteners is directly related to the safety and reliability of critical equipment such as machinery, automobiles, and wind power. Currently, anti-loosening nuts on the market are mainly divided into four categories: friction anti-loosening, mechanical anti-loosening, wedge locking, and anti-loosening nuts made of special materials / structures.

[0003] Friction-based locking mechanisms (such as nylon insert nuts and metal lock nuts) are widely used, but suffer from poor temperature resistance or insufficient reliability in preventing loosening. Mechanical locking mechanisms (such as slotted nuts with cotter pins and double nuts) offer high reliability, but are complex to install and expensive. Wedge-locking mechanisms (such as Nord-Lock washers) offer excellent performance but typically require additional washer assemblies. Locking mechanisms made of special materials / structures (such as thread-locking adhesives and punch-point locking mechanisms) often sacrifice removability or versatility.

[0004] Existing technologies generally suffer from the problem of not being able to simultaneously achieve the desired anti-loosening effect, convenience, cost, and versatility. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a grooved anti-loosening nut that can ensure excellent anti-loosening performance while achieving convenient installation and disassembly and wide applicability.

[0006] This application provides a grooved anti-loosening nut, including a nut body and a threaded hole provided on the nut body. At least one end of the nut body is provided with a wedge-shaped portion and a groove. The tip of the wedge-shaped portion is the axial end of the nut body, and at least part of the groove is located at the end of the wedge-shaped portion.

[0007] Optionally, there may be multiple grooves, which are circumferentially distributed around the axis of the threaded hole.

[0008] Optionally, the width of the groove is 1mm to 3mm and the depth is 0.5mm to 2.5mm.

[0009] Optionally, the groove is a V-shaped groove, a rectangular groove, or a U-shaped groove.

[0010] Optionally, the wedge-shaped portion is in the shape of an annular frustum or a segmented wedge-shaped block, and the inner surface of the wedge-shaped portion is a conical surface or an inclined surface.

[0011] Optionally, the angle between the conical surface and the radial direction of the nut body is 10° to 25°; or, the angle between the inclined surface and the radial direction of the nut body is 10° to 25°.

[0012] Optionally, the thickness of the wedge at the end face is 1 / 10 to 1 / 5 of the standard wall thickness of the nut body.

[0013] Optionally, the threaded surface of the nut body has a textured, non-slip surface.

[0014] Optionally, the uneven anti-slip surface is formed by a sandblasting process.

[0015] Optionally, the anti-loosening nut includes a flange nut, a hexagonal nut, a round nut, or a Torx nut.

[0016] The beneficial effect of this application is that the grooved anti-loosening nut provided by this application achieves excellent anti-loosening performance through the synergistic effect of the wedge-shaped part and the groove. Specifically, when the nut is tightened, the tip of the wedge-shaped part first contacts the surface of the fastener, generating a strong radial engagement force under axial pressure. At the same time, the surface material of the fastener undergoes plastic deformation under extrusion pressure and embeds itself into the groove located at the end of the wedge-shaped part, forming a reliable mechanical locking barrier. In addition, the threads are roughened, creating an anti-slip effect, effectively preventing the nut from turning loose due to vibration. This multi-layered anti-loosening mechanism of "wedge engagement + groove locking" not only significantly improves the reliability of anti-loosening but also has a simple structure, requires no additional accessories, and is easy to install and disassemble, while maintaining the nut's versatility and being suitable for tightening needs under various vibration conditions. Attached Figure Description

[0017] Figure 1 A schematic diagram of a bottom tapered groove structure provided in an embodiment of this application; Figure 2 This is a schematic diagram of a grooved anti-loosening nut with a concave-convex surface on the threaded surface, provided in an embodiment of this application.

[0018] In the diagram: 100, nut body; 110, threaded hole; 120, wedge-shaped part; 130, groove; 140, inner side; 150, concave and convex surface. Detailed Implementation

[0019] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0020] like Figure 1 As shown, the present application provides a grooved anti-loosening nut, including a nut body 100 and a threaded hole 110 provided on the nut body 100. At least one end of the nut body 100 is provided with a wedge-shaped portion 120 and a groove 130. The tip of the wedge-shaped portion 120 is the axial end of the nut body 100, and at least part of the groove 130 is located at the end of the wedge-shaped portion 120.

[0021] Compared with existing technologies, the grooved anti-loosening nut provided in this application achieves superior anti-loosening performance through the synergistic effect of the wedge-shaped portion 120 and the groove 130. Specifically, when the nut is tightened, the tip of the wedge-shaped portion 120 first contacts the surface of the fastener, generating a strong radial engagement force under axial pressure. Simultaneously, the surface material of the fastener undergoes plastic deformation under compressive force and embeds itself into the groove 130 located at the end of the wedge-shaped portion 120, forming a reliable mechanical locking barrier that effectively prevents the nut from loosening due to vibration. This multi-layered anti-loosening mechanism of "wedge engagement + groove 130 locking" not only significantly improves the reliability of anti-loosening but also features a simple structure, requires no additional accessories, and is easy to install and disassemble. Furthermore, it maintains the nut's versatility and is suitable for tightening needs under various vibration conditions.

[0022] In some possible implementations, there are multiple grooves 130, which are circumferentially distributed around the axis of the threaded hole 110.

[0023] Specifically, the circumferentially evenly distributed multi-groove structure 130 forms multiple symmetrical mechanical stop points during operation. When the nut is tightened, the plastic deformation material on the surface of the fastener simultaneously embeds into each groove 130, forming a complete stop ring around the threaded hole 110, effectively preventing the nut from rotating and loosening in any direction. Simultaneously, the even distribution of multiple grooves 130 ensures that the compressive and interlocking forces are evenly distributed across the entire end face, avoiding localized fatigue damage caused by stress concentration and improving the structural reliability and service life of the nut. The number of grooves 130 can be 4, 5, 6, 10, 12, or even more, evenly distributed in the wedge-shaped portion 120.

[0024] In some possible implementations, the width of the groove 130 is 1mm to 3mm and the depth is 0.5mm to 2.5mm.

[0025] For example, the width of the groove 130 can be any typical but non-limiting point value or a range between any two points, such as 1mm, 1.5mm, 2mm, 2.5mm, or 3mm; the depth of the groove 130 can be any typical but non-limiting point value or a range between any two points, such as 0.5mm, 1mm, 1.5mm, 2mm, or 2.5mm. In this case, it can ensure that a sufficiently large and stable mechanical locking protrusion is formed to effectively resist the rotational torque of the nut, and also ensure that the wedge-shaped deformation part has sufficient rigidity and strength to maintain long-term reliable engagement performance, thereby maximizing the mechanical anti-loosening effect while ensuring structural integrity.

[0026] In some possible implementations, the groove 130 can be a V-groove, a rectangular groove, or a U-groove. Specifically, the V-groove, due to its sharp bottom structure, more easily guides the material on the surface of the fastener to flow into the bottom of the groove when the nut is tightened, forming a strong wedge-shaped locking effect, suitable for high-vibration conditions; the rectangular groove provides a larger volume and vertical sidewalls, accommodating more plastically deformable material, generating stronger mechanical resistance, and is easy to process, suitable for mass production; the U-groove, with its smooth bottom transition, has less stress concentration, helping to improve the fatigue strength of the nut end, while still effectively embedding deformable material to achieve reliable stopping. All three groove types can work in conjunction with the wedge-shaped portion 120, balancing the stopping effect, structural strength, and processing cost by optimizing the geometry of the groove 130 while ensuring the end-face engagement function.

[0027] In some possible implementations, the wedge portion 120 is in the shape of an annular frustum or a segmented wedge block, and the inner surface 140 of the wedge portion 120 is a conical surface or an inclined surface.

[0028] Specifically, when the nut is tightened, the annular frustoconical wedge 120 can provide continuous and uniform axial clamping force, so that the entire end face can fully contact the surface of the fastener and produce consistent plastic deformation, thereby enhancing the overall anti-rotation capability; while the segmented wedge block structure retains local high-stress engagement points, it allows each block to independently adjust the embedding depth according to the micro-topography of the contact surface, thereby improving the adaptability to uneven surfaces.

[0029] In some possible implementations, the radial angle between the conical surface and the nut body 100 is 10° to 25°; or, the radial angle between the inclined surface and the nut body 100 is 10° to 25°.

[0030] Specifically, when the included angle is less than 10°, the wedge effect is too weak, making it difficult to generate sufficient axial clamping force and radial expansion force during tightening, resulting in insufficient anti-loosening engagement force. If the included angle exceeds 25°, it will lead to increased local stress concentration, which will not only easily cause cracking or plastic collapse at the end of the nut, but also make it difficult for the surface material of the fastener to flow fully into the groove 130, reducing the mechanical interlocking effect. In the range of 10° to 25°, the inclined surface or equivalent conical surface can effectively guide the surface material of the connected parts to slide into the groove 130 along the inclined direction to form a firm mechanical interlock, and can also generate a moderate radial component force under the action of thread preload, enhancing the frictional resistance between the threaded pairs, while avoiding excessive weakening of the nut body 100 structure.

[0031] In some possible implementations, the thickness of the wedge portion 120 at its end face is 1 / 10 to 1 / 5 of the standard wall thickness of the nut body 100. Within this thickness range, it is possible to ensure that the wedge portion 120 has sufficient rigidity and compressive strength to stably press into the surface of the fastener under preload and guide the material into the groove 130, while also preserving sufficient structural integrity of the nut body 100 to maintain the load-bearing capacity of the threaded pair.

[0032] like Figure 2 As shown, in some possible implementations, the threaded surface of the nut body 100 has a concave-convex surface 150.

[0033] Specifically, during the tightening process of the nut, these protrusions embed into the threaded surface of the mating bolt, forming localized plastic deformation and engagement points, thereby effectively suppressing relative rotation caused by vibration or impact. Thus, by introducing microscopic or macroscopic geometric irregularities into the threaded contact area, the frictional resistance and mechanical interlocking effect between the threaded pairs are significantly enhanced.

[0034] In some possible implementations, the uneven surface 150 is formed through a sandblasting process. High-speed jets of hard abrasive particles impact the workpiece surface, creating uniformly distributed pits, micro-protrusions, and rough textures at a microscale. Specifically, the size of the steel grit used for thread sandblasting is determined by the size of the nut; for example, 0.7 mm diameter steel grit is used to treat the threads of M30 to M48 nuts, and the sandblasting time is 5-8 minutes.

[0035] In some possible implementations, lock nuts include flange nuts, hexagonal nuts, or Torx nuts.

[0036] Example 1 To verify the advancements of the anti-loosening nut of this invention, a series of anti-loosening performance tests were conducted on this product and compared it with the same model from top international manufacturers. The comparison products included: Sample 1, the Japanese Hardlock eccentric double nut anti-loosening nut, which is claimed to be non-loosening for 300 years; Sample 2, the Spirax 30-degree bevel thread anti-loosening nut adopted by the US aerospace industry; Sample 3, the "pressure point anti-loosening nut" used in the Russian military industry; and Sample 4, the anti-loosening nut of this invention.

[0037] Testing unit: Ningbo Zhongji Parts Testing Co., Ltd.

[0038] Test standard: GB / T10431-2008, test method: test frequency: 12.5Hz, amplitude: ±0.8mm, lubrication conditions: Molykote lubricating oil, number of vibrations: 2000 times.

[0039] Test quantity: 8 pieces of each type of sample, using screws and washers of the same material from the same batch. Nut specification: M36. Test results are shown in Tables 1 to 4 below.

[0040] Table 1

[0041] Table 2

[0042] Table 3

[0043] Table 4

[0044] As shown in Tables 1 to 4, Sample 1 (Japanese Hardlock nut) had a maximum residual clamping force of 92.2% and a minimum of 15.6%, with three nuts having residual clamping forces above 90% and two nuts having residual clamping forces below 70%. Sample 2 (American Spirax nut) had a maximum residual clamping force of 85.9%, with none exceeding 90%, and a minimum of 49.4%, with four nuts having residual clamping forces below 70%, indicating an overall mediocre anti-loosening effect. Sample 3 (Russian pressure point nut) had a maximum residual clamping force of 93.7%, but one nut was completely loosened (6%). Sample 4 (anti-loosening nut of this application) had residual clamping forces all above 90%, indicating very stable anti-loosening performance.

[0045] As can be seen from the above, the grooved anti-loosening nut provided in this application achieves excellent anti-loosening performance through the synergistic effect of the wedge-shaped part 120 and the groove 130. Compared with mainstream anti-loosening nuts on the market, under the same test conditions, it has a higher residual axial force retention rate and a better anti-loosening effect, effectively improving the reliability and stability of the nut in a strong vibration environment.

[0046] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0047] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A grooved locking nut, comprising a nut body (100) and a threaded hole (110) provided on the nut body (100), characterized in that: The nut body (100) has a wedge-shaped portion (120) and a groove (130) at at least one end, the tip of the wedge-shaped portion (120) being the axial end of the nut body (100), and at least part of the groove (130) being located at the end of the wedge-shaped portion (120).

2. The anti-loosening nut according to claim 1, characterized in that, The number of grooves (130) is multiple, and they are circumferentially distributed around the axis of the threaded hole (110).

3. The anti-loosening nut according to claim 2, characterized in that, The groove (130) has a width of 1mm to 3mm and a depth of 0.5mm to 2.5mm.

4. The anti-loosening nut according to claim 1, characterized in that, The groove (130) is a V-shaped groove, a rectangular groove, or a U-shaped groove.

5. The anti-loosening nut according to claim 1, characterized in that, The wedge-shaped portion (120) is in the shape of an annular frustum or a segmented wedge-shaped block, and the inner surface (140) of the wedge-shaped portion (120) is a conical surface or an inclined surface.

6. The anti-loosening nut according to claim 5, characterized in that, The radial angle between the conical surface and the nut body (100) is 10°~25°; Alternatively, the angle between the inclined surface and the radial direction of the nut body (100) is 10°~25°.

7. The anti-loosening nut according to claim 6, characterized in that, The thickness of the wedge (120) at the end face is 1 / 10 to 1 / 5 of the standard wall thickness of the nut body (100).

8. The anti-loosening nut according to any one of claims 1 to 7, characterized in that, The threaded surface of the nut body (100) has a concave-convex surface (150).

9. The anti-loosening nut according to claim 8, characterized in that, The uneven surface (150) is formed by a sandblasting process.

10. The anti-loosening nut according to any one of claims 1 to 7, characterized in that, The anti-loosening nuts include flange nuts, hexagonal nuts, round nuts, or Torx nuts.

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