Crawler type vibration self-tightening nut

Abstract

The invention discloses a crawler type vibration self-tightening nut, and belongs to the field of mechanical fasteners. The nut comprises a nut body (1) and a soft elastic body (2). The nut body (1) is provided with a pressing face (12) used for pressing a connected piece in the assembling process, the face is provided with at least one inclined blind hole (13), and the axis of the blind hole (13) and the pressing face (12) form an included angle alpha (1 degree < = alpha < = 90 degrees). The blind hole (13) is filled with the soft elastic body (2), one end of the soft elastic body (2) is a pressed end (21) extending out of the hole opening, and the end face of the pressed end (21) and the pressing face (12) are coplanar or parallel. After the nut is pre-tightened, the soft elastic body (2) is periodically compressed and rebounded in the inclined blind hole under vibration, a tangential component force F generated by decomposition of a restoring force F of the soft elastic body (2) tangentially forms a self-tightening torque M for driving the nut to rotate in the tightening direction, and the effect that the nut is tightened along with vibration is achieved. A spiral compression spring (3) can be coaxially embedded in the soft elastic body (2) so as to enhance the performance.

Description

Technical Field

[0001] This invention relates to the field of mechanical connection fastener technology, and specifically to an anti-loosening nut capable of adaptive locking under vibration conditions. Background Technology

[0002] Threaded fasteners are prone to loosening under dynamic loads such as vibration and impact, which has been a long-standing problem in mechanical engineering. To address this issue, various anti-loosening nut technologies have been developed. Among the technologies that utilize structural self-tightening forces, the following two solutions are most relevant to the problem addressed by this invention:

[0003] 1. Spring-stored self-tightening nut (as disclosed in US Patent US4812096A): This type typically consists of a main nut, a secondary nut, and a coiled spring connecting the two. Its anti-loosening effect relies entirely on the limited elastic potential energy pre-stored during initial installation; once this energy is depleted, its self-tightening function fails. Furthermore, its multi-part assembly structure is relatively complex.

[0004] 2. Helical surface washer type self-tightening device (as disclosed in Chinese Patent CN106286558A): This solution has a smooth helical bevel machined on the contact surface between the nut body and a special washer to generate self-tightening force. The anti-loosening effect of this technology depends on the external special washer, and its self-tightening force comes from the static mechanical transmission of the helical surface. The structure is not compact enough and the response efficiency to continuous micro-amplitude vibration is insufficient.

[0005] In summary, existing technologies based on structures to generate self-tightening forces have limitations such as passive energy sources (relying on pre-stored energy or static transfer) and complex structures (relying on multiple components or additional parts). They cannot actively and continuously capture energy from environmental vibrations to maintain long-term reliable anti-loosening forces. Summary of the Invention

[0006] The technical problem to be solved by the present invention

[0007] To address the shortcomings of existing self-tightening nuts, which rely on limited pre-stored energy, have complex structures, and cannot continuously utilize environmental vibration energy, this invention provides a crawler-type vibration self-tightening nut. Its purpose is to actively and continuously convert harmful environmental vibrations into beneficial anti-loosening power through an extremely simple built-in structure, achieving integrated structure, adaptive function, and long-lasting anti-loosening effect.

[0008] Technical solution of the present invention

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A crawler-type vibrating self-tightening nut includes a nut body and a soft elastomer. The nut body has an internal thread and a clamping surface for clamping the connected parts during assembly; at least one oblique blind hole is formed inside the nut body, located in the solid portion between the clamping surface and the internal thread, with its axis forming an angle α with the plane of the clamping surface, where 1°≤α≤90°; the soft elastomer fills and is fixed in the oblique blind hole; one end of the soft elastomer is a pressure-bearing end protruding from the opening of the blind hole, and the end face of the pressure-bearing end is coplanar or parallel to the clamping surface.

[0011] Preferably, the included angle α is 15°≤α≤60°.

[0012] Preferably, the soft elastomer has a cylindrical structure.

[0013] Preferably, the soft elastomer is made of rubber, silicone, or polyurethane elastic material.

[0014] Preferably, the number of the obliquely placed blind holes is 2-8, and they are evenly or non-uniformly distributed along the circumference of the nut body.

[0015] Preferably, the length of the pressure-bearing end extending out of the blind hole opening is 0.1 to 3 mm.

[0016] Preferably, the nut body is a common hexagonal nut, flange nut, or round nut.

[0017] Preferably, a helical compression spring is coaxially embedded within the soft elastic body.

[0018] Preferably, the end of the soft elastomer that contacts the bottom of the blind hole has an arc-shaped taper to facilitate press-fitting.

[0019] Beneficial effects of the present invention

[0020] Compared with the prior art, the present invention has the following significant advantages:

[0021] 1. Active energy capture and conversion: Through the innovative structure of "oblique blind hole + soft elastomer", the environmental vibration energy is directly converted into mechanical energy to drive its own tightening, realizing a fundamental transformation from "passive anti-loosening" to "active self-tightening".

[0022] 2. Durable and adaptive effect: The self-tightening torque originates from continuous environmental vibration. As long as vibration exists, the self-tightening effect continues, solving the problem of performance decay in traditional methods. The system can automatically achieve dynamic equilibrium and maintain a stable anti-loosening force.

[0023] 3. Highly integrated and simplified structure: The core functional components are completely built into a single nut body in an innovative structure, without any external parts, making the structure extremely simple and compact.

[0024] 4. Adjustable performance and wide applicability: By selecting elastomer materials with different hardness or pre-embedding helical compression springs coaxially inside, the magnitude of the self-tightening torque can be easily adjusted to adapt to different vibration conditions from light to heavy, thus broadening the application range.

[0025] 5. Good assembly processability: The arc-shaped taper designed at one end of the soft elastomer facilitates its smooth and reliable pressing into the blind hole, which is beneficial for industrial production and assembly. Attached Figure Description

[0026] Figure 1 This is a three-dimensional cross-sectional view of an embodiment of the present invention (with the pressing surface facing upwards).

[0027] Figure 2 for Figure 1 The view shown is obtained by projecting the nut along its axial direction onto the clamping surface (12).

[0028] Figure 3 This is a schematic diagram illustrating the working principle of the present invention.

[0029] Figure 4 This is a schematic diagram of an embodiment of the soft elastomer built-in helical compression spring of the present invention.

[0030] Explanation of the labels in the diagram:

[0031] 1-Nut body, 11-Internal thread, 12-Clamping surface, 13-Angled blind hole;

[0032] 2- Soft elastomer, 21- Compression end, 3- Helical compression spring;

[0033] F - Elasticity, F 切向 - Tangential elastic force, F 轴向 - Axial elastic force, M - Self-tightening torque, α - Included angle. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] Example 1

[0036] See Figure 1 This embodiment provides a crawler-type vibration self-tightening nut. The nut body 1 is a standard right-hand threaded external hexagonal nut with an internal thread 11. One end face is used to clamp the connected parts during assembly and is defined as the clamping face 12. For clear illustration of the structure, Figure 1The clamping surface 12 is drawn facing upwards. Three obliquely placed circular blind holes 13 are machined into the solid metal part of the nut body 1, evenly distributed along the circumference. The angle α between the axis of the blind holes 13 and the plane containing the clamping surface 12 is 30°.

[0037] The soft elastomer 2 is a cylindrical rubber rod. One end of it, near the bottom of the blind hole (13), is machined with an arc-shaped taper to facilitate insertion. It is pressed into the blind hole 13 and fixed by an interference fit. Its pressure end 21 protrudes about 1 mm from the opening of the blind hole 13, and this end face is precision machined to ensure that it is strictly coplanar with the clamping surface 12 of the nut.

[0038] See Figure 2 It is along the axis of the nut, towards the clamping surface 12 (i.e. Figure 1 The view projected from above clearly shows the uniform distribution of the three blind holes 13 on the pressing surface 12.

[0039] Working principle (combined) Figure 3 ):

[0040] After the nut is tightened onto the bolt in the conventional manner, its pressing surface 12 presses against the surface of the workpiece, so that the pressure end 21 of all the soft elastomers 2 is uniformly compressed, and the initial elastic force F is stored inside the elastomer.

[0041] When external vibrations cause the nut to loosen even slightly, the pressure of the clamping surface 12 on the pressure end 21 decreases instantaneously. The soft elastomer 2 rebounds under its own elasticity, attempting to return to its original length. Since its other end abuts against the bottom of the inclined blind hole 13, this rebound force F can ultimately be decomposed into two components: one is an axial elastic force F along the nut's axis. 轴向 And a tangential elastic force F perpendicular to the nut axis and tangential to the bottom of the cavity. 切向 .

[0042] The tangential elastic force F 切向 Acting on the cavity wall, it generates a torque that drives the nut body 1 to rotate. Based on the characteristics of a right-hand thread, in... Figure 1 and Figure 3 Under the established unified perspective (with clamping surface 12 facing upwards), this torque drives the nut to rotate counterclockwise, which is the tightening direction. This torque is... Figure 3 The self-tightening torque M is marked with an arc-shaped arrow.

[0043] When vibration causes the nut to have a slight tendency to tighten, the compressed end 21 is further compressed, and the elastomer stores more elastic energy to prepare for the next rebound.

[0044] This cycle repeats itself, with each vibration cycle driving the soft elastomer 2 to complete one cycle of "compression energy storage - rebound work," generating a small self-tightening torque M. Macroscopically, the effects of multiple vibrations accumulate and superimpose, achieving a "tightening with vibration" effect until the total self-tightening axial force generated by the vibration input energy reaches a dynamic equilibrium with the residual holding axial force after attenuation due to material relaxation, micro-slippage, and other system dissipation. At this point, the nut will maintain a stable, anti-loosening state near this equilibrium point.

[0045] Example 2 (Example of nut body shape)

[0046] The nut body 1 is not limited to a standard hexagonal nut; it can also be any conventional nut type with a clamping function surface, such as a flange nut (the clamping surface 12 includes the flange portion) or a round nut. As long as the oblique blind hole 13 is opened in the solid portion between its clamping surface 12 and the internal thread 11 and filled with a soft elastomer 2, the vibration self-tightening function of the present invention can be achieved.

[0047] Example 3 (with built-in reinforced compression spring)

[0048] To further adapt to high preload or strong vibration conditions, soft elastomers can be reinforced. For example... Figure 4 As shown, in this embodiment, a helical compression spring 3 is coaxially embedded inside the soft elastomer 2 along its axial direction. This helical compression spring 3 can be embedded during rubber vulcanization or elastomer casting. This design significantly improves the overall elastic modulus, fatigue resistance, and creep resistance of the elastomer assembly, thereby providing a larger and more stable restoring force F and self-tightening torque M without changing the external structural dimensions of the nut, enabling the system to achieve better dynamic balance under higher load conditions.

[0049] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Any equivalent modifications or substitutions made under the guidance of the principles of this invention, such as the angle, number, and distribution of blind holes, the shape, material, fixing method, end taper, or type of built-in reinforcement of the elastomer, should be included within the scope of protection of this invention.

Claims

1. A crawler-type vibrating self-tightening nut, characterized in that, include: The nut body (1) has an internal thread (11) and a clamping surface (12) for clamping the connected parts during assembly; At least one oblique blind hole (13) is opened inside the nut body (1), located in the solid part between the clamping surface (12) and the internal thread (11), and its axis forms an angle α with the plane where the clamping surface (12) is located, where 1°≤α≤90°; A soft elastomer (2) is filled and fixed in the inclined blind hole (13); one end of the soft elastomer (2) is a pressure end (21) extending out of the opening of the blind hole (13), and the end face of the pressure end (21) is coplanar or parallel to the pressing surface (12).

2. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The included angle α is 15°≤α≤60°.

3. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The soft elastomer (2) has a cylindrical structure.

4. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The soft elastomer (2) is made of rubber, silicone or polyurethane elastic material.

5. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The number of the obliquely placed blind holes (13) is 2-8, and they are evenly or non-uniformly distributed along the circumference of the nut body (1).

6. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The length of the pressure end (21) extending out of the opening of the blind hole (13) is 0.1 to 3 mm.

7. The crawler-type vibration self-tightening nut according to claim 1, characterized in that: The nut body (1) is a common hexagonal nut, flange nut, or round nut.

8. The crawler-type vibrating self-tightening nut according to any one of claims 1 to 7, characterized in that: A helical compression spring (3) is coaxially embedded in the soft elastomer (2).

9. The crawler-type vibrating self-tightening nut according to any one of claims 1 to 8, characterized in that: The end of the soft elastomer (2) that contacts the bottom of the blind hole (13) has an arc-shaped taper that facilitates pressing and fitting.

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