Bidirectional thread dynamic locking locknut assembly

Abstract

The invention belongs to the technical field of fasteners, and provides a bidirectional thread dynamic locking locknut assembly which comprises a screw, a main nut and an auxiliary nut, and the screw comprises a main rod, an auxiliary rod and a hexagonal head; by means of the innovative double-nut design and the reverse thread structure, the automatic locking function under the high-frequency vibration and high-cold and high-temperature environment is achieved, namely the characteristic that the more vibration is, the tighter the vibration is, the nut loosening problem is effectively solved, meanwhile, the assembly can be produced through the conventional turning and thread machining technology, and the production cost is reduced. Special equipment or complex processes are not needed, large-scale popularization and application are facilitated, cost is low, machining is easy and convenient, mounting and dismounting can be easily completed through a conventional tool, professional skills or special tools are not needed, good adaptability to high-cold and high-temperature environments is achieved, and the connector is suitable for various scenes needing high-reliability connection; and particularly, the device has obvious advantages under high-frequency vibration and extreme environment conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of fasteners, in particular to a bidirectional threaded dynamic locking anti-loosening nut assembly. Background Art

[0002] According to statistics from the China Association of Machinery Industry, equipment failure accidents caused by loose bolts account for 35%, of which vibration and temperature changes are the main causes. In the fields of high-value equipment such as mechanical equipment, transportation, aerospace, and ships, the reliability of connectors is directly related to the safe operation and performance of the equipment.

[0003] However, when traditional bolts and nuts are subjected to high-frequency vibration for a long time or are in a high-temperature or cold environment, they often become loose due to factors such as material fatigue, thermal expansion and contraction, which in turn leads to connection failure or even safety accidents. Although there are some anti-loosening bolt and nut products on the market, they generally have the problems of high cost, complex processing, poor anti-loosening effect or weak adaptability.

[0004] To this end, those skilled in the art have proposed a bidirectional threaded dynamic locking anti-loosening nut assembly to solve the problems raised by the background art.

[0005] The above information disclosed in this background technology is only used to increase the understanding of the background technology of the present invention and therefore, it may include information that does not constitute the prior art known to a person of ordinary skill in the art. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a bidirectional threaded dynamic locking anti-loosening nut assembly to solve the problem that traditional bolts and nuts in the prior art often loosen due to factors such as material fatigue, thermal expansion and contraction when subjected to high-frequency vibration for a long time or in a high-cold or high-temperature environment.

[0007] To achieve the above-mentioned purpose, the present invention provides a bidirectional threaded dynamic locking anti-loosening nut assembly, including a screw, a main nut and a secondary nut, the screw including a main rod, a secondary rod and a hexagonal head, the main rod is provided with a main thread on the outside, and the secondary rod is provided with a secondary thread opposite to the main thread on the outside, the main nut is provided with a first internal thread matching the main thread on the inside, and the secondary nut is provided with a second internal thread matching the secondary thread on the inside, the main nut and the secondary nut are respectively fitted on the main rod and the secondary rod through threads, and there is a dynamic locking fit between the main nut and the secondary nut.

[0008] Preferably, the diameter of the secondary rod is smaller than the diameter of the primary rod.

[0009] Preferably, the pitches of the main thread and the secondary thread are both adapted to a dynamic locking function, the main thread and the secondary thread are both adapted to a bidirectional locking thread form, and the diameter of the secondary nut is smaller than the diameter of the main nut.

[0010] Preferably, both the main nut and the auxiliary nut are made of metal materials.

[0011] Preferably, the main nut is made of 42CrMo alloy steel, and the auxiliary nut is made of 17-4PH stainless steel.

[0012] Preferably, a hardened layer is provided on the outer part of the auxiliary nut.

[0013] Preferably, the main nut and the auxiliary nut can also be made of engineering plastics.

[0014] Preferably, the engineering plastic material is glass fiber reinforced nylon, and the engineering plastic also contains nano-silica additives.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Through the innovative double-nut design and reverse-thread structure, the present invention realizes the automatic locking function under high-frequency vibration and cold / high-temperature environments, that is, the characteristic of "the more it vibrates, the tighter it gets", effectively solving the problem of nut loosening. At the same time, the components of the present invention can be produced by using conventional turning and threading technologies, without the need for special equipment or complex processes, which is conducive to large-scale popularization and application. The cost is low, the processing is simple, and the installation and disassembly can be easily completed with conventional tools, without the need for professional skills or special tools, and it has good adaptability to cold / high-temperature environments, being applicable to various scenarios requiring highly reliable connections, especially having significant advantages under high-frequency vibration and extreme environmental conditions.

[0017] The above summary is only for the purpose of the specification and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will be readily apparent by referring to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of a two-way threaded dynamic locking anti-loosening nut assembly in an embodiment of the present invention;

[0019] Figure 2 is a cross-sectional view of a two-way threaded dynamic locking anti-loosening nut assembly in an embodiment of the present invention;

[0020] Figure 3 is a partial structural schematic diagram of a bolt of a two-way threaded dynamic locking anti-loosening nut assembly in an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of the overall structural decomposition of a two-way threaded dynamic locking anti-loosening nut assembly in an embodiment of the present invention;

[0022] Figure 5 This is a cross-sectional view of the auxiliary nut of a two-way threaded dynamic locking and loosening prevention nut assembly in an embodiment of the present invention.

[0023] In the figure:

[0024] 1. Screw rod; 11. Main rod; 12. Main thread; 13. Auxiliary rod; 14. Auxiliary thread; 15. Hexagonal head; 2. Main nut; 21. First internal thread; 3. Auxiliary nut; 31. Second internal thread; 32. Hardened layer. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. It should be noted that the drawings are schematic and not drawn to scale. For the sake of clarity and convenience in the figure, the relative dimensions and proportions of the parts shown in the figure are exaggerated or reduced in size and illustrated. Any dimension is only exemplary and not limiting.

[0026] Embodiment:

[0027] Please refer to Figure 1 - Figure 5 As shown, a two-way threaded dynamic locking and loosening prevention nut assembly includes a screw rod 1, a main nut 2, and an auxiliary nut 3. The screw rod 1 includes a main rod 11, an auxiliary rod 13, and a hexagonal head 15. The main rod 11 is externally provided with a main thread 12, and the auxiliary rod 13 is externally provided with an auxiliary thread 14 opposite to the direction of the main thread 12. The inner side of the main nut 2 is provided with a first internal thread 21 matching the main thread 12, and the inner side of the auxiliary nut 3 is provided with a second internal thread 31 matching the auxiliary thread 14. The main nut 2 and the auxiliary nut 3 are respectively fitted on the main rod 11 and the auxiliary rod 13 through threads, and there is a dynamic locking fit between the main nut 2 and the auxiliary nut 3. The main rod 11 is the main part of the screw rod 1, and the main thread 12 thereon is used to cooperate with the main nut 2 to provide basic connection and fastening functions. The length and pitch design of the main thread 12 ensure that the main nut 2 can be tightened thereon and provide sufficient pre-tightening force to meet the connection requirements of the equipment. The auxiliary thread 14 on the auxiliary rod 13 is opposite to the direction of the main thread 12. When the main nut 2 has a loosening tendency under vibration or temperature change, the auxiliary thread 14 generates an additional locking force through reverse cooperation with the auxiliary nut 3 to prevent the main nut 2 from loosening. The hexagonal head 15 is used to cooperate with tools such as wrenches to facilitate the installation and disassembly of the screw rod 1, ensuring that the tightening and loosening operations of the screw rod 1 are simple and fast. The main nut 2 is matched with the main thread 12 of the main rod 11 through the first internal thread 21 to tighten the screw rod 1 and provide the main fastening force. The tightening of the main nut 2 is the basis for the fastening of the entire assembly. The auxiliary nut 3 is matched with the auxiliary thread 14 of the auxiliary rod 13 through the second internal thread 31 to achieve the dynamic locking function through the reverse thread structure.

[0028] Specifically, the diameter of the auxiliary rod 13 is smaller than that of the main rod 11.

[0029] Furthermore, the pitches of the main thread 12 and the auxiliary thread 14 are both adapted to the dynamic locking function. The main thread 12 and the auxiliary thread 14 are both adapted to the thread form of bidirectional locking. The diameter of the auxiliary nut 3 is smaller than that of the main nut 2.

[0030] Furthermore, both the main nut 2 and the auxiliary nut 3 are made of metal materials.

[0031] Furthermore, the main nut 2 is made of 42CrMo alloy steel, and the auxiliary nut 3 is made of 17-4PH stainless steel. 42CrMo alloy steel is a high-strength alloy steel with a relatively high tensile strength (≥800 MPa) and good yield strength, while maintaining relatively high toughness. It can maintain its shape under high-strength pre-tightening force and will not undergo plastic deformation. The main nut 2 needs to bear a large pre-tightening force during the fastening process. The high strength and high toughness of 42CrMo alloy steel can ensure that the main nut 2 will not break due to stress concentration during tightening, and can also maintain the structural integrity under high-frequency vibration environment. After 42CrMo alloy steel is quenched and tempered (such as HRC28-32), the surface hardness is moderate and it has good wear resistance. During the dynamic locking process, relative movement will occur between the main nut 2 and the main thread 12 of the screw rod 1. Good wear resistance can reduce thread wear and extend the service life of the nut.

[0032] 17-4PH stainless steel is a precipitation-hardening stainless steel with high strength (tensile strength ≥800 MPa) and good corrosion resistance. After solution aging treatment, it can reach relatively high hardness and strength while maintaining good toughness. The auxiliary nut 3 needs to work together with the main nut 2 during the dynamic locking process. High strength and good corrosion resistance can ensure that the auxiliary nut 3 can still maintain good performance in high and low temperature environments (such as -60°C to 200°C). 17-4PH stainless steel is suitable for surface hardening treatment, such as nitriding treatment. After nitriding treatment, a hardened layer 32 with relatively high hardness (such as 50-80 μm) is formed on the surface, which can significantly improve the wear resistance and anti-seizure property of the nut. During the dynamic locking process, relative movement will occur between the auxiliary nut 3 and the auxiliary thread 14 of the screw rod 1. The surface hardened layer 32 can effectively reduce thread wear, prevent thread seizure, and extend the service life of the auxiliary nut 3. The main nut 2 and the auxiliary nut 3 can be produced by conventional turning and thread processing techniques, without special equipment or complex processes.

[0033] Furthermore, the surface of the auxiliary nut 3 is hardened with a hardened layer 32 formed by nitriding treatment. The hardened layer 32 improves the surface hardness and wear resistance of the auxiliary nut 3, while enhancing the corrosion resistance, ensuring a good locking effect even in harsh environments.

[0034] Working principle: The main nut 2 and the auxiliary nut 3 are successively sleeved on the main rod 11 and the auxiliary rod 13 of the screw rod 1. The main nut 2 is screwed onto the main thread 12, and the auxiliary nut 3 is screwed onto the auxiliary thread 14. According to the directions of the main thread 12 and the auxiliary thread 14, the main nut 2 can be tightened clockwise and the auxiliary nut 3 counterclockwise, or the main nut 2 can be tightened counterclockwise and the auxiliary nut 3 clockwise. The main nut 2 provides the main fastening force, and the auxiliary nut 3 is in a standby state, ready to play a role when there is vibration or temperature change. When the equipment is in a high-frequency vibration or high-low temperature environment, the main nut 2 may tend to loosen because the vibration force is greater than the torque force. Since the auxiliary nut 3 is connected to the auxiliary rod 13 with a reverse thread, the movement of the main nut 2 actually increases the friction between the main nut 2 and the screw rod 1. This increased friction automatically locks the main nut 2 to prevent it from loosening. Since the thread directions of the main nut 2 and the auxiliary nut 3 are opposite, during vibration, the main nut 2 and the auxiliary nut 3 will be more and more tightly combined. This synergistic effect further enhances the locking effect of the assembly, ensuring a reliable connection even under extreme conditions. When tightening the nut, due to special working conditions, the nut may not be tightened firmly. A gasket can be added to be able to tighten it. The main nut 2 is made of 42CrMo alloy steel, and the auxiliary nut 3 is made of 17-4PH stainless steel and is specially treated. These materials can effectively resist material fatigue and corrosion in high-low temperature environments, ensuring the reliability of the assembly under extreme conditions. The hardened layer 32 on the surface of the auxiliary nut 3 improves the surface hardness and wear resistance. In high-low temperature environments, the hardened layer 32 can effectively prevent thread wear and corrosion, extending the service life of the assembly;

[0035] The main nut 2 and the auxiliary nut 3 can also be made of engineering plastics. The engineering plastics are glass fiber reinforced nylon, and the engineering plastics also contain nano-silica additives. Glass fiber reinforced nylon has high mechanical strength and wear resistance. The addition of glass fibers significantly improves the tensile strength and impact resistance of nylon, enabling it to withstand large pre-tightening forces and dynamic locking forces. Nano-silica additives further enhance the wear resistance and fatigue resistance of the material, reduce the wear of the threads during dynamic locking, and extend the service life of the nuts. The main nut 2 and the auxiliary nut 3 are made of engineering plastics and are processed by processes such as injection molding. The production efficiency is high and the processing cost is low. Compared with metal materials, injection molding can quickly produce complex shapes and structures without complex machining. Metal nuts usually require surface treatment to improve wear resistance and corrosion resistance, while engineering plastic nuts have good surface properties and do not require additional surface treatment, further reducing the production cost. They are suitable for lightweight fields such as drones, toys, and robot joints.

[0036] As can be seen from the above, through the innovative double-nut design and reverse thread structure, the automatic locking function in high-frequency vibration and cold / hot high-temperature environments, that is, the characteristic of "the more it vibrates, the tighter it gets", is achieved, effectively solving the problem of nut loosening. At the same time, the components of the present invention can be produced using conventional turning and threading techniques, without the need for special equipment or complex processes, which is conducive to large-scale popularization and application. The cost is low, the processing is simple, and the installation and disassembly can be easily completed using conventional tools without the need for professional skills or special tools, and it has good adaptability to cold / hot high-temperature environments and is suitable for various scenarios requiring highly reliable connections, especially having significant advantages in high-frequency vibration and extreme environmental conditions.

[0037] The standard parts used in the present invention can all be purchased from the market. The special-shaped parts can be customized according to the descriptions in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machines, parts, and equipment all adopt conventional models in the prior art. Coupled with the circuit connection adopting the conventional connection method in the prior art, it will not be elaborated here. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0038] In the attached drawings of the disclosed embodiments of the present invention, only the structures related to the disclosed embodiments are involved. Other structures can refer to the usual designs. Without conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0039] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A bidirectional threaded dynamic locking anti-loosening nut assembly, comprising a screw (1), a main nut (2) and a secondary nut (3), characterized in that: The screw rod (1) comprises a main rod (11), a secondary rod (13) and a hexagonal head (15); the main rod (11) is provided with a main thread (12) on the outside; the secondary rod (13) is provided with a secondary thread (14) in the opposite direction to the main thread (12) on the outside; the main nut (2) is provided with a first internal thread (21) matching the main thread (12) on the inside; the secondary nut (3) is provided with a second internal thread (31) matching the secondary thread (14) on the inside; the main nut (2) and the secondary nut (3) are respectively fitted on the main rod (11) and the secondary rod (13) through threads, and a dynamic locking fit exists between the main nut (2) and the secondary nut (3).

2. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 1, characterized in that: The diameter of the secondary rod (13) is smaller than the diameter of the primary rod (11).

3. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 2, characterized in that: The pitches of the main thread (12) and the secondary thread (14) are both adapted to a dynamic locking function, the main thread (12) and the secondary thread (14) are both adapted to a bidirectional locking thread form, and the diameter of the secondary nut (3) is smaller than the diameter of the main nut (2).

4. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 3, characterized in that: The main nut (2) and the auxiliary nut (3) are both made of metal material.

5. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 4, characterized in that: The main nut (2) is made of 42CrMo alloy steel, and the auxiliary nut (3) is made of 17-4PH stainless steel.

6. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 5, characterized in that: The secondary nut (3) is provided with a hardened layer (32) on the outside.

7. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 1, characterized in that: The main nut (2) and the auxiliary nut (3) can also be made of engineering plastics.

8. A bidirectional threaded dynamic locking anti-loosening nut assembly according to claim 7, characterized in that: The engineering plastic material is glass fiber reinforced nylon, and the engineering plastic also contains nano silicon dioxide additive.

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