Mutually prime slotted reversible pin lock bolted joint pair

Abstract

The application discloses a kind of coprime slot type reversible latch bolt connection pair, belong to fastener technical field.It includes bolt, hexagon nut, elastic energy storage element and elastic hoop locking element;Bolt threaded rod is evenly provided with M first axial slots, nut inner thread hole port is evenly provided with N second axial slots, M and N are coprime, and the locking window is formed by alignment;Elastic energy storage element is clamped between nut and connected component and is in compression state, provides small angle rotation allowance for nut;Locking protruding part of elastic hoop locking element is embedded in locking window and simultaneously abuts two side groove walls, forms circumferential limit;Its inner ring tightly holds the outer thread surface of threaded rod, uses tooth type to hinder axial movement, forms axial limit;Circumferential limit and axial limit jointly form double constraint.The application realizes no pre-tightening force loss assembly, two-way rigid anti-loose and reversible disassembly and recycling, is suitable for wind power, pressure vessel, rail transit and other alternating vibration working conditions.

Description

Technical Field

[0001] This invention belongs to the field of fastener technology, specifically relating to a reversible pin anti-loosening bolt connection pair with a coprime groove. Background Technology

[0002] Threaded connections are one of the most widely used connection methods in mechanical engineering, and their reliability is directly related to the operational safety of equipment. However, under harsh working conditions such as alternating vibration and impact loads, threaded connections are prone to loosening, resulting in a decrease in preload, which can lead to structural displacement, connection failure, or even equipment downtime in severe cases.

[0003] Existing anti-loosening structures are mainly divided into two categories: friction-type anti-loosening and mechanical anti-loosening. Friction-type anti-loosening methods, such as anti-loosening rubber, nylon nuts, and ordinary spring washers, have poor vibration fatigue resistance and a high probability of failure under long-term service conditions. Traditional mechanical anti-loosening structures, such as cotter pins and locking washers, are prone to plastic deformation during disassembly and assembly, and most can only be used once. They also require a large amount of maintenance consumables and have long downtime for maintenance.

[0004] Existing patent CN2266052Y discloses a slotted alignment bolt locking structure, which relies on the slotted bolt and nut to cooperate with a limiting block to achieve mechanical locking, providing a certain anti-loosening effect. However, this structure has a simple alignment method and a small number of alignment windows, which can easily cause preload loss during assembly; the locking structure is biased towards a permanent locking design, resulting in poor disassembly and assembly convenience, difficulty in repeated reuse, and insufficient structural configuration for large and heavy-duty bolt applications. Summary of the Invention

[0005] Purpose of the invention This invention addresses the problems in the prior art by providing a reversible pin anti-loosening bolt connection pair with a coprime groove, which solves the problems of inconvenient disassembly and assembly, easy damage to components, inability to be reused, and the weakening of the bolt's own strength by traditional slotted bolts. Technical solution

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A reversible pin anti-loosening bolt connection assembly with a mutual prime groove type includes a bolt, a hexagonal nut, an elastic energy storage element, and an elastic clamp locking component; On the effective engagement section of the bolt's threaded shank, M axial grooves extending axially are uniformly formed along the circumference of the major diameter cylindrical surface of the thread, where M ≥ 2; the bottom of the first axial groove is located above the root of the thread; on the internal threaded hole port section of the hexagonal nut, N axial grooves extending axially are uniformly formed along the circumference of the inner wall of the threaded hole, where N ≥ 2; the greatest common divisor of M and N is 1; when the bolt and the hexagonal nut rotate relative to each other, the first and second axial grooves can be aligned to form a locking window that extends to the thread engagement area; The elastic energy storage element is fitted onto the threaded rod section on the outside of the bolt and clamped between the hexagonal nut and the connected part, in a compressed assembly state, so that the hexagonal nut has a small angular rotational displacement margin relative to the bolt, which is limited by the elastic deformation of the elastic energy storage element. The elastic clamp locking component is an elastic ring-shaped member with a locking protrusion on one axial side, which extends along the bolt axial direction. When the locking protrusion extends into the locking window, it simultaneously abuts against the side walls of the first and second axial grooves to restrict the rotation of the hexagonal nut, thus forming a circumferential limit. The outer thread surface of the inner ring elastically grips the threaded rod, using the external thread profile to prevent the clamp from moving axially along the rod body, thus forming an axial limit. The circumferential and axial limits together form a double constraint on the elastic clamp locking component.

[0007] Technical Principles and Boundaries The core of this invention lies in constructing a collaborative closed loop of "high-density alignment of coprime slots—energy storage rebound compensation—double clamping restraint." Here, the coprime relationship between M and N is a prerequisite for forming a high-density alignment window and the mathematical basis for achieving "alignment without preload loss."

[0008] In this invention, the mathematical property that M and N are coprime forms a precise match with the physical properties of the elastic energy storage element. Specifically: High-density alignment window: Since M and N are coprime and the grooves are uniformly distributed, during the relative rotation of the bolt and nut, the number of times the first axial groove and the second axial groove overlap is the product of M and N, and the overlap angle interval is 360° / (M×N). This makes the locking window have a high-density uniform distribution in the circumferential direction.

[0009] Precise matching of springback margin: After the elastic energy storage element is compressed, it provides a small but definite small-angle rotational displacement margin for the hexagonal nut. This margin matches the minimal overlap angle interval formed by the mutual mass grooves, ensuring that when manually tightening the nut, the operator can easily find the nearest alignment point within the springback stroke of the energy storage element without having to loosen it in the opposite direction.

[0010] The formation of a collaborative closed loop: The high-density alignment window provides the spatial basis for "rapid alignment," while the energy storage rebound provides the power source for "non-destructive alignment." The combination of the two completely eliminates the preload loss caused by repeated loosening and unloosening of nuts in traditional solutions. Subsequently, the embedding of the elastic clamp locking component solidifies this temporary alignment state into a permanent mechanical lock.

[0011] The aforementioned bolts, hexagonal nuts, elastic energy storage elements, and elastic clamp locking components have the following connection relationships and synergistic effects: The first axial groove of the bolt and the second axial groove of the hexagonal nut, through the mutual prime relationship of M and N, form multiple locking window positions during one relative rotation, providing a high-density alignment point base for locking. An elastic energy storage element is sandwiched between the hexagonal nut and the connected part and is in a compressed assembly state, ensuring that the hexagonal nut always has a small angular rotational displacement margin relative to the bolt, limited by the elastic deformation of the elastic energy storage element. When the nut is tightened to the set preload, the elastic potential energy stored in the elastic energy storage element drives the nut to rotate slightly, allowing the first and second axial grooves to manually align and form locking windows without releasing the preload. The locking protrusion of the elastic clamp locking component is embedded into this locking window along the bolt axial direction, simultaneously abutting against the side walls of the first and second axial grooves to restrict the rotation of the hexagonal nut, constituting circumferential limiting; at the same time, the outer thread surface of the inner ring elastically clamps the threaded rod of the elastic clamp locking component, using the external thread profile to prevent the clamp from moving axially along the rod body, constituting axial limiting. The aforementioned circumferential and axial limiting mechanisms together form a dual constraint on the elastic clamp locking component, ensuring that the connection pair maintains a stable locked state under vibration conditions. Through the coordinated force chain and functional chain of "high-density alignment via mutual mass grooves—energy storage and rebound compensation—dual clamp limiting," the four components achieve the technical effects of alignment assembly without preload loss, bidirectional rigidity to prevent loosening, and reversible disassembly and recycling.

[0012] Furthermore, with each rotation of the hexagonal nut relative to the bolt, the first axial groove and the second axial groove overlap multiple times in the circumferential direction to form a locking window.

[0013] Furthermore, the values ​​of M and N are selected based on the nominal diameter D of the bolt: When the nominal diameter D≤M16, M and N take values ​​of (3,4) or (4,5); When M18<D≤M30, M and N take values ​​of (5,6) or (6,7); When D > M30, M and N take values ​​of (7,8) or (8,9).

[0014] Furthermore, the locking protrusion is integrally formed with the elastic clamp locking body, and there is no relative gap between the two. The locking protrusion is formed and set at a preset position in the circumferential direction of the elastic clamp locking part.

[0015] Furthermore, the locking protrusion has a polygonal cross-section structure, and the locking protrusion forms a surface-to-surface contact fit with the walls of the first axial groove and the second axial groove, respectively.

[0016] Furthermore, the elastic energy storage element is any one of a disc spring washer, a wave spring, or a disc spring assembly.

[0017] Furthermore, the elastic clamp locking component is a detachable component independent of the bolt and hexagonal nut; the locking protrusion extends into the threaded engagement area of ​​the bolt and hexagonal nut.

[0018] Furthermore, in the assembled state, the locking protrusion is embedded inside the locking window, and the elastic clamp locking member elastically clamps the external thread surface of the threaded rod.

[0019] Furthermore, the two ends of the elastic clamp locking member are folded outward to form operating ears, and the surface of the operating ears is provided with an anti-slip structure.

[0020] Furthermore, the elastic clamp locking member can be radially expanded by squeezing the operating ear with external force, and can be reset by its own elastic rebound after the external force is removed; in the rebound reset state, the locking protrusion is stably embedded in the locking window and tightly fits the groove walls of the first axial groove and the second axial groove. Beneficial effects

[0021] Compared to existing technologies, this invention forms a single-cycle, multiple-alignment window through the mutual prime fit of the bolt M-slot and the nut N-slot, and with the small-angle springback allowance of the nut provided by the elastic energy storage element sandwiched between the nut and the connected parts, the nut completes slot alignment without releasing the preload. The above-mentioned "mutual prime high-density alignment" and "energy storage springback compensation" work together to ensure that there is no loss of preload during the entire assembly process.

[0022] Compared to existing technologies, the elastic clamp locking component uses the inner ring to elastically clamp the outer thread surface of the threaded rod, and uses the external thread profile to prevent the clamp from moving axially along the rod body, thus achieving axial floating limit; at the same time, the locking protrusion abuts against the two side walls of the first axial groove and the second axial groove to limit the rotation of the hexagonal nut; the axial limit and circumferential limit form a double constraint, which makes the connection pair maintain stable preload under vibration conditions and has excellent vibration resistance performance.

[0023] Compared to existing technologies, the entire assembly and disassembly process relies on the elastic deformation of the elastic clamp itself. The main components of the bolts and nuts will not undergo plastic deformation. The entire set of components can be disassembled and reused multiple times, reducing the later maintenance costs.

[0024] Compared to existing technologies, the bottom of the first axial groove is set above the thread root, so the effective load-bearing cross section of the threaded rod will not decrease after grooving, thus balancing the anti-loosening effect and the tensile strength of the bolt itself. Corresponding coprime groove parameters are matched for bolts of different nominal diameters, and the moment of inertia of the spring section is increased for large-diameter bolts, which is suitable for heavy-load working conditions.

[0025] Compared to existing technologies, the elastic clamp locking component is an independent and detachable accessory, making it easy to assemble and disassemble; the polygonal locking protrusions and groove walls are in surface contact, resulting in stronger shear resistance and higher structural reliability. Attached Figure Description

[0026] Figure 1 This is a three-dimensional exploded view of the reversible pin anti-loosening bolt connection pair of the coprime groove type of the present invention, showing the exploded structure and spatial assembly position relationship of each component. Figure 2 This is an axial sectional view of the reversible pin anti-loosening bolt connection pair of the comass groove type of the present invention, showing the mating structure of each component in the assembled state; Figure 3 This is a schematic diagram of the assembly and alignment operation of the elastic clamp locking component of the present invention, showing the operation structure of the expansion and alignment of the elastic clamp locking component; Figure 4 This is a schematic diagram of the locking assembly operation of the elastic clamp locking component of the present invention, showing the assembly structure of the elastic clamp locking component snapping into the locking window; Figure 5 This is an axial sectional view of the reversible pin anti-loosening bolt connection assembly of the coprime groove type of the present invention after assembly, showing the cooperation and limiting structure of each component in the locked state.

[0027] Explanation of reference numerals in the attached figures: 1— Bolt; 11—First axial groove; 2—Elastic energy storage element; 3—Hexagonal nut; 31—Second axial groove; 4—Elastic clamp locking element; 41—Locking protrusion; 42—Operating ear; 5—Locking window; 6—Connected part. Detailed Implementation

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. This embodiment is only used to explain the present invention and does not limit the scope of protection of the present invention.

[0029] Example 1: Overall Structure and Working Principle (Coprime Scheme) like Figures 1-2 As shown, a reversible pin anti-loosening bolt connection assembly with a mutual mass groove is mainly composed of a bolt 1, a hexagonal nut 3, an elastic energy storage element 2, and an elastic clamp locking element 4.

[0030] On the effective engagement section of the threaded rod of bolt 1, M axial grooves extending axially are uniformly opened along the circumference of the major diameter cylindrical surface of the thread. In this embodiment, M=3. On the internal threaded hole port section of hexagonal nut 3, N axial grooves extending axially are uniformly opened along the circumference of the inner wall of the threaded hole. In this embodiment, N=4. The greatest common divisor of M=3 and N=4 is 1. When bolt 1 and hexagonal nut 3 rotate relative to each other, the first axial groove and the second axial groove are aligned to form a locking window 5 that extends to the thread engagement area. The bottom of the first axial groove 11 is higher than the root of the thread tooth.

[0031] The elastic clamp locking component 4 is an open-type elastic ring-shaped component with a locking protrusion 41 on one axial side. The locking protrusion 41 extends along the bolt axial direction. After assembly, the locking protrusion 41 extends into the locking window 5 and abuts against the side groove walls to restrict the rotation of the hexagonal nut 3, thus forming a circumferential limit. The inner ring of the elastic clamp locking component 4 elastically clamps the outer thread surface of the threaded rod, using the tooth profile to prevent the clamp from moving axially along the rod body, thus forming an axial limit. The circumferential limit and the axial limit together form a double constraint on the elastic clamp locking component 4.

[0032] In this embodiment, the elastic energy storage element 2 is a disc spring washer, which is fitted on the outside of the threaded rod and clamped between the hexagonal nut 3 and the connected part 6. After assembly, the elastic energy storage element 2 is in a compressed state. Relying on the elastic deformation of the elastic energy storage element 2, the hexagonal nut 3 can achieve a small angle of rotation to complete the slot alignment. The rotation range is limited by the deformation of the elastic energy storage element.

[0033] In the assembled state, the preload is applied between the hexagonal nut 3 and the connected part 6, and the elastic energy storage element 2 is compressed and stores energy. When the first axial groove 11 and the second axial groove 31 align due to the slight rotation of the hexagonal nut 3 to form the locking window 5, the locking protrusion 41 of the elastic clamp locking member 4 is inserted into the locking window 5 along the bolt axis and simultaneously abuts against the groove walls on both sides, restricting the rotation of the hexagonal nut 3. At the same time, the inner ring of the elastic clamp locking member 4 clamps the external thread profile of the threaded rod, using the thread profile to prevent the clamp from moving along the axial direction of the rod. In the above force path, the preload → elastic energy storage element 2 → small-angle rebound of the hexagonal nut 3 → groove alignment → bidirectional abutment of the locking protrusion 41 → inner ring of the elastic clamp locking member 4 clamps the external thread, forming a closed-loop cooperation, constraining both circumferential and axial directions.

[0034] Example 2: Bolt selection and strength matching design For bolts with different nominal diameters, select the corresponding combination of complementary grooves: for nominal diameters D≤M16, select (3,4) or (4,5); for M18<D≤M30, select (5,6) or (6,7); for D>M30, select (7,8) or (8,9).

[0035] The locking protrusion 41 is integrally formed with the elastic clamp locking part body, with no assembly gap; the locking protrusion 41 adopts a polygonal cross-section structure, forming a surface-to-surface contact with the groove wall, improving the shear resistance; the elastic clamp locking part is made of spring steel, and the surface of the locking protrusion 41 is hardened to a hardness ≥ HRC55, which is higher than the thread surface of bolts and nuts, reducing the amount of wear after long-term use.

[0036] This invention not only ensures the structural strength after the bolt slots are cut, but also achieves high-density alignment, assembly without preload loss, and reversible disassembly and recycling. It is suitable for alternating vibration conditions such as wind power, pressure vessels, and rail transportation.

Claims

1. A reversible pin anti-loosening bolt connection assembly with a coprime groove type, characterized in that, Includes bolts (1), hexagonal nuts (3), elastic energy storage elements (2), and elastic clamp locking elements (4); On the effective engagement section of the threaded rod of the bolt (1), M first axial grooves (11) are uniformly opened along the circumference of the major diameter cylindrical surface of the thread, M≥2; the bottom of the first axial groove (11) is located above the root of the thread tooth. The internal threaded hole section of the hexagonal nut (3) is provided with N axially extending second axial grooves (31) evenly distributed along the circumferential direction of the inner wall of the threaded hole, where N≥2; The greatest common divisor of M and N is 1; when the bolt (1) and the hexagonal nut (3) rotate relative to each other, the first axial groove (11) and the second axial groove (31) can be aligned to form a locking window (5) that extends to the thread engagement area. The elastic energy storage element (2) is fitted on the threaded rod section outside the bolt (1) and sandwiched between the hexagonal nut (3) and the connected part (6), and is in a compressed assembly state, so that the hexagonal nut (3) has a small angular rotational displacement margin relative to the bolt (1) limited by the elastic deformation of the elastic energy storage element (2); The elastic clamp locking member (4) is an elastic ring-shaped member with a locking protrusion (41) on one axial side, and the locking protrusion (41) extends along the bolt (1) axially. When the locking protrusion (41) extends into the locking window (5), it simultaneously abuts against the side walls of the first axial groove (11) and the second axial groove (31) to restrict the rotation of the hexagonal nut (3), thus forming a circumferential limit. The inner ring of the elastic clamp locking member (4) elastically clamps the outer thread surface of the threaded rod, and uses the external thread profile to prevent the clamp from moving axially along the rod body, thus forming an axial limit; The circumferential and axial limiting devices together form a dual constraint on the elastic clamp locking member (4).

2. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, For every rotation of the hexagonal nut (3) relative to the bolt (1), the first axial groove (11) and the second axial groove (31) overlap multiple times in the circumferential direction to form the position of the locking window (5).

3. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, Select the values ​​of M and N according to the nominal diameter D of the bolt (1): When the nominal diameter D≤M16, M and N take the values ​​of (3,4) or (4,5). When M18<D≤M30, M and N take values ​​of (5,6) or (6,7). When D > M30, M and N take values ​​of (7,8) or (8,9).

4. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The locking protrusion (41) and the elastic clamp locking member (4) are integrally formed, with no relative gap between them. The locking protrusion (41) is formed and set at a preset position in the circumference of the elastic clamp locking member (4).

5. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The locking protrusion (41) has a polygonal cross-section structure, and the locking protrusion (41) forms a surface-to-surface contact fit with the groove walls of the first axial groove (11) and the second axial groove (31).

6. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The elastic energy storage element (2) is any one of a disc spring washer, a wave spring, or a disc spring assembly.

7. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The elastic clamp locking member (4) is a detachable component independent of the bolt (1) and the hexagonal nut (3); the locking protrusion (41) extends into the threaded engagement area of ​​the bolt (1) and the hexagonal nut (3).

8. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, When assembled, the locking protrusion (41) is embedded inside the locking window (5), and the elastic clamp locking member (4) elastically clamps the external thread surface of the threaded rod.

9. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The two ends of the elastic clamp locking member (4) are folded outward to form operating ears (42), and the surface of the operating ears (42) is provided with an anti-slip structure.

10. The reversible pin anti-loosening bolt connection assembly with a coprime groove type according to claim 1, characterized in that, The elastic clamp locking member (4) can be radially expanded by squeezing the operating ear (42) with external force, and can be reset by its own elastic rebound after the external force is removed; in the rebound reset state, the locking protrusion (41) is stably embedded in the locking window (5) and closely fits the groove walls of the first axial groove (11) and the second axial groove (31).

11. An assembly method for a reversible anti-loosening pin connection pair with a coprime groove type according to claim 1, characterized in that, Includes the following steps: S1: Pass the bolt (1) through the connected part (6), screw it into the hexagonal nut (3), and tighten the hexagonal nut (3) to the set preload; at this time, the elastic energy storage element (2) is compressed, and the first axial groove (11) and the second axial groove (31) are misaligned; S2: Manually tighten the hexagonal nut (3) to make it rotate slightly within the small angle rotation margin provided by the elastic energy storage element (2), so that the first axial groove (11) and the second axial groove (31) are aligned to form a locking window (5). S3: The elastic clamp locking part (4) is fitted onto the bolt (1), so that the locking protrusion (41) is embedded in the locking window (5). The locking protrusion (41) simultaneously abuts against the side walls of the first axial groove (11) and the second axial groove (31), restricting the rotation of the hexagonal nut (3). S4: When disassembly is required, manually pinch the operating ears (42) at both ends of the elastic clamp locking part (4) to expand it radially, and the locking protrusion (41) will disengage from the locking window (5), and the hexagonal nut (3) can be unscrewed.

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