Bolt anti-loosening structure used under large torque effect

Abstract

A bolt anti-loosening structure used under the action of large torque comprises a connecting body, an outer ring, an inner ring, a connecting block and a fastening bolt, a connecting hole is machined in the connecting body, the inner diameter of each part of the connecting hole is matched with the outer diameter of a main body part of the connecting block, and a threaded section matched with the fastening bolt is arranged in the connecting hole; the outer ring and the inner ring are of a wedge-shaped ring-shaped closed ring structure, the outer diameter of the inner ring and the inner diameter of the outer ring form a concentric circle structure, the inner surface of the outer ring is a conical surface, the outer surface of the inner ring is a conical surface, the inner surface of the outer ring is matched with the outer surface of the inner ring, and when the outer ring and the inner ring are matched, the formed axial section is rectangular. The anti-loosening device mainly comprises the tapered wedge-shaped outer ring and the tapered wedge-shaped inner ring, is simple in structure and low in manufacturing and processing cost, and can achieve the anti-loosening effect through coordinated deformation under the action of strong vibration.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology, specifically relating to a bolt anti-loosening structure for use under high torque. Background Technology

[0002] Bolted connections are the most widely used fastening method in mechanical engineering, and their anti-loosening performance directly affects the safety and reliability of equipment operation. Under complex working conditions such as dynamic loads, vibration and shock, and temperature fluctuations, threaded pairs are prone to loosening due to factors such as microscopic slippage of the contact surface, preload decay, or material creep, which can lead to connection failure.

[0003] Currently, anti-loosening measures mainly include the following: The first is to counteract lateral sliding force by increasing the frictional resistance between the threaded pair or contact surfaces. Typical solutions include spring washers that use elastic rebound to compensate for preload loss, but these are prone to stress loosening at high temperatures, leading to a significant reduction in preload; double-nut structures generate additional stress through axial alignment, but occupy a large axial space, increasing weight and making them unsuitable for thin-walled connections. The second is a mechanical interlocking structure that uses physical limits to directly block the relative movement of the threaded pair. A cotter pin and slotted nut combination achieves rotational freedom constraint through a rigid pin, while a retaining washer uses bending to create spatial interference. However, this anti-loosening structure requires additional installation steps, making the assembly process cumbersome. The third is an innovative thread design that suppresses loosening from the geometric structure source. A combination of left and right-hand threads forms a mechanical self-locking mechanism, eliminating the need for spring washers or other auxiliary components. However, its manufacturing cost is high, and its anti-loosening effect is limited in high-temperature environments. Summary of the Invention

[0004] The purpose of this invention is to provide a bolt anti-loosening structure for use under high torque. This invention mainly consists of a tapered outer ring and an inner ring. The structure is simple, has low manufacturing and processing costs, and can achieve the anti-loosening effect through coordinated deformation under strong vibration.

[0005] To achieve the above objectives, the technical solution of this utility model is: a bolt anti-loosening structure for use under high torque, comprising a connecting body, an outer ring, an inner ring, a connecting block, and a fastening bolt. The connecting body has a connecting hole machined inside, and the inner diameter of each part of the connecting hole matches the outer diameter of the main body of the connecting block. The connecting hole is provided with a threaded hole that mates with the fastening bolt.

[0006] The outer ring and inner ring are closed ring structures in the shape of flat circular rings. The outer diameter of the inner ring and the inner diameter of the outer ring form a concentric circle structure. The inner surface of the outer ring is a conical surface, and the outer surface of the inner ring is a conical surface. The inner surface of the outer ring and the outer surface of the inner ring match each other. When the two are fitted together, the axial cross section formed is rectangular.

[0007] Furthermore, the connecting block is a multi-level cylindrical structure with a small platform, a middle platform, and a large platform. The connecting block can be fitted with an inner ring and an outer ring and then installed on the connecting body. The outer surface of the small platform is in close contact with the inner and outer rings. The connecting hole includes a limiting hole section one and a limiting hole section two. The diameter of the limiting hole section one is equal to the diameter of the small platform, and the diameter of the limiting hole section two is equal to the diameter of the middle platform.

[0008] Furthermore, the diameter of the large platform is larger than the diameter of the second limiting hole segment of the connecting block.

[0009] Furthermore, the inner and outer rings are made of high-strength alloy steel.

[0010] Compared with the prior art, the beneficial effects of this utility model are:

[0011] 1. The anti-loosening component mainly consists of a tapered outer ring and an inner ring. Because it is a symmetrical annular structure, the pressure distribution is more uniform, avoiding local stress concentration and thus improving overall stability. This structure is simple and has low manufacturing and processing costs.

[0012] 2. When the fastening bolts are tightened with a specific high torque, axial tensile force acts on the tapered combination ring. Due to the contact between the inner and outer ring tapered surfaces, the tensile force is decomposed into a radial component and an axial clamping force. Furthermore, the tapered angle design satisfies the self-locking condition that the tapered angle is less than the friction angle between materials. The radial component forces the inner ring to expand outward and the outer ring to contract inward, forming a high-strength radial clamping force. This clamping force generates significant friction in the tapered surface contact area. Even if external vibration attempts to induce axial loosening, the friction between the tapered surfaces effectively prevents relative sliding, achieving "geometric locking."

[0013] 3. The inner and outer rings are connected to the matching structure through the end face and the inner and outer ring surfaces, which increases the connection area and can effectively prevent bolts from loosening and locking parts from twisting or shifting. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the tensioning structure;

[0015] Figure 2 This is a schematic diagram of the bolted connection structure installation.

[0016] Figure 3 This is a schematic diagram of the overall structure of the bolted connection;

[0017] In the diagram: 1. Connector; 2. Outer ring; 3. Inner ring; 4. Connecting block; 4-1. Small platform; 4-2. Middle platform; 4-3. Large platform; 5. Fastening bolt; 6. Connecting hole; 6-1. Limiting hole section one; 6-2. Limiting hole section two; 7. Threaded hole. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] like Figures 1-3 As shown, a bolt anti-loosening structure for high torque includes a connecting body 1, an outer ring 2, an inner ring 3, a connecting block 4, and a fastening bolt 5. The connecting body 1 is the required connection part. The connecting body 1 has a connecting hole 6 machined inside. The interior of the connecting hole 6 is a multi-faceted cylindrical structure. The inner diameter of each part of the connecting hole 6 matches the outer diameter of the main body of the connecting block 4. The connecting hole 6 is provided with a threaded hole 7 that mates with the fastening bolt 5.

[0020] The outer ring 2 and inner ring 3 form a flat, closed-loop ring structure. The outer diameter of the inner ring 3 and the inner diameter of the outer ring 2 form a concentric circle structure. The inner surface of the outer ring 2 is conical, and the outer surface of the inner ring 3 is also conical. The inner surfaces of the outer ring 2 and the inner ring 3 match. Since the axial cross-sections of both the inner ring 3 and the outer ring 2 are wedge-shaped, the overall axial cross-section formed when they are fitted together is rectangular. After being compressed by axial pressure, the outer ring expands outward, and the inner ring contracts inward, undergoing elastic deformation. Under conditions such as vibration, this slight synergistic deformation achieves an anti-loosening effect.

[0021] The connecting block 4 is a multi-level cylindrical structure with three levels of platforms, including a small platform 4-1, a middle platform 4-2, and a large platform 4-3. The connecting block 4 can be fitted with an inner ring 3 and an outer ring 2 and then installed on the connecting body 1. The outer surface of the small platform 4-1 is in close contact with the inner ring 3 and the outer ring 2. The diameter of the middle platform 4-2 is equal to the outer diameter of the outer ring 2. The connecting hole 6 includes a limiting hole section 1 6-1 and a limiting hole section 2 6-2. When the small platform 4-1 is in contact with the inner ring 3 and the outer ring 2, the diameter of the limiting hole section 1 6-1 is equal to the diameter of the small platform 4-1, the diameter of the limiting hole section 2 6-2 is equal to the diameter of the middle platform 4-2, and the diameter of the large platform 4-3 is larger than the diameter of the limiting hole section 2 6-2, which serves as a limiting device. The large platform 4-3 has a threaded hole 7 machined axially inside to facilitate the connection of the fastening bolt 5 with the connecting part 1, which serves to prevent loosening of the outer ring 2 and the inner ring 3 and to connect them. The fastening bolt 5 is used to fasten the outer ring 2, inner ring 3, and connecting block 4 and connect them to the connecting body 1, thus providing a fastening function. After the bolt 5 is fastened to the connecting body 1, it causes deformation of the inner ring 3 and outer ring 2. The deformation of the inner ring 3 and outer ring 2 acts on the connecting body 1 and connecting block 4, preventing the connecting block 4 from twisting or displacing.

[0022] The diameter of the large platform 4-3 is larger than the diameter of the limiting hole section 6-2 of the connecting block 4, thus serving as a limit to prevent the connecting block 4 from being screwed in too deeply. The inner ring 3 and outer ring 2 are made of high-strength alloy steel, mainly including: 35SiMn, 40SiMn, 35CrMo, 42CrMo, 30Cr, 35Cr, 40Cr, etc. This is because adding alloying elements such as Cr and Mn to the chemical composition of structural steel can significantly improve the tensile strength and axial stiffness of the material. Under the preload of the fastening bolt 5, the inner ring 3 undergoes elastic deformation due to radial expansion, while the outer ring 2 is compressed inward; both store elastic potential energy. When external vibration or temperature changes cause a slight decrease in the bolt preload, the elastic deformation energy is automatically released, pushing the conical surface to re-tighten, compensating for the loss of preload. This dynamic adjustment capability enables the structure to perform excellently in continuous vibration or alternating load environments. Elastic deformation not only counteracts the decay of preload but also converts vibration energy into heat energy through the material's internal energy dissipation mechanism, further suppressing the tendency to loosen. To improve the reliability of anti-loosening measures, the conical surface can also be surface-treated to enhance friction. Surface hardening can significantly increase the hardness of the conical surface, reducing fretting wear during long-term use.

[0023] During installation, the outer ring 2 first embeds into the connecting hole of the connector 1 to achieve radial constraint. The inner ring 3 forms initial contact with the outer ring 2 through its conical surface. The positioning of the connecting block 4 ensures symmetrical load distribution. When a high preload torque is applied, the axial pressure generated by the fastening bolt 5 causes the outer ring 2 and inner ring 3 to undergo coordinated elastic deformation: the outer ring 2 contracts radially, while the inner ring 3 extends axially. This coupled deformation generates extremely high contact stress, with its normal force reaching several times that of traditional bolt connections. Its unique energy dissipation mechanism can convert vibration kinetic energy into elastic potential energy. Through deformation coordination, part of the axial preload is converted into radial clamping force, forming a stable "stress self-locking" effect at the friction interface, solving the problem of preload attenuation in traditional bolt connections. Through the innovative bolt anti-loosening mechanism, the requirements for anti-loosening under high torque are met, along with the convenience of installation and the flexibility of maintenance, significantly improving transmission efficiency and equipment lifespan. Simultaneously, under the combined action of the bolt anti-loosening mechanism, the connecting block 4 will not rotate or displace even when subjected to an axial force in the circumferential direction centered on the axis of bolt 5.

Claims

1. A bolt anti-loosening structure for use under high torque, characterized in that: It includes a connector (1), an outer ring (2), an inner ring (3), a connecting block (4), and a fastening bolt (5). The connector (1) has a connecting hole (6) inside. The inner diameter of each part of the connecting hole (6) matches the outer diameter of the main body of the connecting block (4). The connecting hole (6) has a threaded hole (7) inside that mates with the fastening bolt (5). The outer ring (2) and inner ring (3) are closed ring structures in the shape of flat circular rings. The outer diameter of the inner ring (3) and the inner diameter of the outer ring (2) form a concentric circle structure. The inner surface of the outer ring (2) is a conical surface, and the outer surface of the inner ring (3) is a conical surface. The inner surface of the outer ring (2) and the outer surface of the inner ring (3) match each other. When the two are in contact, the axial cross section formed is rectangular.

2. The bolt anti-loosening structure according to claim 1, characterized in that: The connecting block (4) is a multi-level cylindrical structure, including a small platform (4-1), a middle platform (4-2) and a large platform (4-3). The connecting block (4) can be fitted with an inner ring (3) and an outer ring (2) and then installed on the connecting body (1). The outer surface of the small platform (4-1) is in close contact with the inner ring (3) and the outer ring (2). The connecting hole (6) includes a limiting hole section one (6-1) and a limiting hole section two (6-2). The diameter of the limiting hole section one (6-1) is equal to the diameter of the small platform (4-1), and the diameter of the limiting hole section two (6-2) is equal to the diameter of the middle platform (4-2).

3. A bolt anti-loosening structure for use under high torque as described in claim 2, characterized in that: The diameter of the large platform (4-3) is greater than the diameter of the limiting hole segment two (6-2) of the connecting block (4).

4. A bolt anti-loosening structure for use under high torque as described in claim 2, characterized in that: The inner ring (3) and outer ring (2) are made of high-strength alloy steel.

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