Adjustable left-hand thread opposite-abutting double-nut lock bolt assembly and assembling method

Abstract

The invention provides an adjustable left-hand thread opposite-abutting double-nut anti-loosening bolt assembly and an assembling method. The adjustable left-hand thread opposite-abutting double-nut anti-loosening bolt assembly comprises a bolt. A plurality of rod part grooves are formed in the rod part of the bolt in the axial direction, so that a rod part boss is formed between every two adjacent rod part grooves; a plurality of bushing grooves are formed in the inner wall of the bushing in the axial direction, so that bushing bosses are formed between the adjacent bushing grooves, the bushing bosses are buckled in the rod part grooves, and the bushing grooves are buckled in the rod part bosses, so that the bushing is buckled on the bolt; an inner hole of the nut is provided with an inner thread in the axial direction, and the outer circumferential face of the lining is provided with an outer thread matched with the inner thread of the nut so that the nut can be connected to the lining in a screwed mode. The two nuts with opposite screwing directions are screwed on the two bushings which are buckled on the bolt and have opposite screwing directions, so that when the nut tightly attached to one side of a fastened piece is loosened and twisted due to a vibration load, the other nut must be reversely screwed and twisted with equal torque, the tightening torque is mutually offset, the lockable pre-tightening force is kept unchanged, and good self-locking is achieved; and the permanent anti-loosening effect is achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of fasteners, and in particular relates to an adjustable reverse-threaded double-nut anti-loosening bolt assembly and an assembly method. Background Art

[0002] A fastener is a mechanical element used to connect and fix two or more parts. It achieves the fastening function by threaded connection and is widely used in many fields such as industry, construction, automobile, aerospace, electronics, etc. Bolt assemblies often serve in alternating loads such as vibration, temperature change, and impact. This means that when bolt assemblies are negatively affected by vibration loads, temperature difference loads, impact loads, alternating loads, etc., they are required to still have a fastening function and stable and lasting anti-loosening performance.

[0003] In actual use, the most common form of fastening failure is caused by the loosening of the bolt assembly itself. Therefore, it is of great practical significance to scientifically design the anti-loosening form of bolted connections and take effective anti-loosening measures. Summary of the invention

[0004] Therefore, the purpose of the present application is to provide an adjustable reverse-threaded double-nut anti-loosening bolt assembly and an assembly method, which at least solves the anti-loosening problem under external load mentioned in the background technology.

[0005] In order to solve the above problems, the first aspect of the present application provides an adjustable reverse threaded double nut anti-loosening bolt assembly, including a bolt, a bushing and a nut;

[0006] The bolt includes a rod, and the outer peripheral surface of the rod is processed with a plurality of radial annular rod grooves along the axial direction, so that radial annular rod bosses are formed between adjacent rod grooves; the inner wall of the bushing is processed with a plurality of radial annular bushing grooves along the axial direction, so that radial annular bushing bosses are formed between adjacent bushing grooves, the bushing bosses are buckled in the rod grooves, and the bushing grooves are buckled on the rod bosses, so that the bushing is buckled on the bolt; the inner hole of the nut is processed with an internal thread along the axial direction, and the outer peripheral surface of the bushing is processed with an external thread matching the internal thread of the nut, so that the nut is screwed onto the bushing.

[0007] Optionally, there are at least two rod grooves on the same cross section, and the portion between adjacent rod grooves is a partitioned radial limiting boss.

[0008] Optionally, the rod bosses arranged in parallel along the axial direction are connected via the radial limiting bosses respectively.

[0009] Optionally, the bushing is of two-piece type, and when the two halves of the bushing are buckled together, the bushing boss at the joint is continuous.

[0010] Optionally, there are at least two bushing bosses on the same cross section, and the portion between the bushing bosses is a partitioning groove.

[0011] Optionally, the groove is communicated with the bushing groove arranged along the axial direction.

[0012] Optionally, the nut includes a load-bearing nut and a locking nut, and the rotation direction of the internal thread of the load-bearing nut is opposite to that of the internal thread of the locking nut.

[0013] Optionally, the bushing includes a load-bearing bushing and a locking bushing, and the rotation direction of the external thread of the load-bearing bushing is opposite to that of the external thread of the locking bushing.

[0014] Optionally, the bolt includes a nut, and at least a portion of the rod of the bolt near the nut is a bare rod, a fastener is mounted on the bare rod, the rod groove at least partially extends to the inner side of an inner hole of the fastener, a load-bearing bushing and a locking bushing are mounted on the portion of the rod groove that is exposed from the fastener, the load-bearing nut is screwed on the load-bearing bushing to press the fastener, and the locking nut is screwed on the locking bushing to press the load-bearing nut.

[0015] The second aspect of the present application provides an assembly method of an adjustable reverse threaded double-nut anti-loosening bolt assembly, which uses the adjustable reverse threaded double-nut anti-loosening bolt assembly, and the anti-loosening bolt assembly is used to lock a fastener; the assembly method includes:

[0016] The bolt passes through the fastener; the first group of bushings are placed close to the fastener and snapped onto the bolt, and then the corresponding nuts are screwed into the first group of bushings to tighten the fastener; the second group of bushings are placed close to the end faces of the nuts of the first group to snap onto the bolt, and then the corresponding nuts are screwed into the second group of bushings to tighten the nuts screwed onto the first group of bushings.

[0017] By means of the above technical solution, the present invention has at least the following beneficial effects:

[0018] The embodiment of the present application provides an adjustable reverse-threaded double-nut anti-loosening bolt assembly, which is a sleeve of a fastener on the bare rod portion and part of the rod groove of the bolt rod; first install a bushing, then screw the corresponding nut on the bushing and tighten it against the end face of the fastener; then install another bushing, and then screw the corresponding nut on the bushing and tighten it against the end face of the previous nut; here, the internal threads of the two bushings have opposite rotation directions, and the external threads of the two nuts also have opposite rotation directions. When in use, the nuts and bushings need to be assembled in pairs, and their positions are flexibly adjustable along the axial direction of the bolt. When the vibration load causes the nut close to one side of the fastener to loosen and produce a twisting trend, the other nut will inevitably produce a reverse equal-torque tightening and twisting trend, and the loosening and tightening torques offset each other, so that the lockable preload remains unchanged, achieving the purpose of good self-locking relaxation, thereby realizing a "permanent" anti-loosening effect. The strength of the groove on the shank of the bolt is higher than that of ordinary standard parts, ensuring that the strength of the bolt assembly is not lower than that of standard parts of the same specification. Due to the top action of nuts with opposite rotation directions, the vibration loosening stress is offset. Except for the preload, the assembly does not need to bear additional load stress during service.

[0019] For each set of nut and bushing threaded connections used in combination, the two-piece bushings of split design, although positioned close to each other, are ultimately in different spatial positions. The oscillating displacement states under vibration conditions will not be absolutely synchronized. The pair of two-piece bushings will have irregular movement dislocations, and at the same time will cause their external external threads to form movement dislocations, breaking the statically engaged threaded continuous docking state, while the internal thread of the nut is a continuous whole and will not be dislocated. When the nut tends to loosen, the two bushing threads are dislocated and constrained from loosening, preventing the nut from loosening. A working state similar to "random buckling" will be formed between the internal and external threads, producing a natural dynamic self-locking and anti-loosening effect, making the nut itself less likely to loosen.

[0020] The embodiment of the present application provides an assembly method for an adjustable reverse-threaded double-nut anti-loosening bolt assembly. The assembly method is simple, the assembly time is short, and the technical requirements for the operator are relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a bolt of an adjustable reverse-threaded double-nut anti-loosening bolt assembly according to an embodiment of the present application;

[0022] Figure 2 For the embodiments of this application Figure 1 AA cross-section diagram;

[0023] Figure 3 For the embodiments of this application Figure 1 BB cross-section diagram;

[0024] Figure 4 This is a front view of a bushing of an adjustable reverse threaded double nut anti-loosening bolt assembly according to an embodiment of the present application;

[0025] Figure 5 A side view of a bushing of an adjustable reverse threaded double nut anti-loosening bolt assembly according to an embodiment of the present application;

[0026] Figure 6 This is a front view of the nut of the adjustable reverse threaded double nut anti-loosening bolt assembly according to the embodiment of the present application;

[0027] Figure 7 A schematic diagram of a half-section of a nut of an adjustable reverse-threaded double-nut anti-loosening bolt assembly according to an embodiment of the present application;

[0028] Figure 8 This is a schematic assembly diagram of the adjustable reverse-threaded double-nut anti-loosening bolt assembly after the fastener is locked according to an embodiment of the present application.

[0029] The reference numerals are:

[0030] 1. Bolt; 11. Groove on the rod; 12. Boss on the rod; 13. Radial limiting boss;

[0031] 21. Bushing groove; 22. Bushing boss; 23. Groove; 24. Load-bearing bushing; 25. Locking bushing;

[0032] 3. Nut; 31. Load-bearing nut; 32. Locking nut;

[0033] 4. Fastened parts. DETAILED DESCRIPTION

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0038] See also Figures 1 to 8 As shown, according to a first aspect of an embodiment of the present application, there is provided an adjustable reverse threaded double nut anti-loosening bolt assembly, comprising a bolt 1, a bushing and a nut 3;

[0039] The bolt 1 includes a rod, and a plurality of radial annular rod grooves 11 are processed along the axial direction on the outer peripheral surface of the rod, so that radial annular rod bosses 12 are formed between adjacent rod grooves 11; a plurality of radial annular bushing grooves 21 are processed along the axial direction on the inner wall of the bushing, so that radial annular bushing bosses 22 are formed between adjacent bushing grooves 21, and the bushing bosses 22 are buckled in the rod grooves 11, and the bushing grooves 21 are buckled on the rod bosses 12, so that the bushing is buckled on the bolt 1 without radial axial displacement; an internal thread is processed along the axial direction on the inner hole wall of the nut 3, and an external thread matching the internal thread of the nut 3 is processed on the outer peripheral surface of the bushing, so that the nut 3 can be well screwed to the bushing.

[0040] The fastener 4 is mounted on the bare rod part and part of the rod groove of the bolt; first install a bushing, then screw the corresponding nut on the bushing and tighten it against the end face of the fastener 4; then install another bushing, then screw the corresponding nut on the bushing and tighten it against the end face of the previous nut; here, the internal threads of the two bushings have opposite rotation directions, and the external threads of the two nuts also have opposite rotation directions. When in use, the nuts and bushings need to be assembled in pairs, and their positions are flexibly adjustable along the axial direction of the bolt. When the vibration load causes the nut close to one side of the fastener 4 to loosen and produce a twisting trend, the other nut will inevitably produce a reverse equal torque tightening and twisting trend, and the loosening and tightening torques offset each other, so that the locking preload remains unchanged, achieving the purpose of good self-locking relaxation, thereby realizing a "permanent" anti-loosening effect. The strength of the groove on the shank of the bolt is higher than that of ordinary standard parts, ensuring that the strength of the bolt assembly is not lower than that of standard parts of the same specification. Due to the top action of nuts with opposite rotation directions, the vibration loosening stress is offset. Except for the preload, the assembly does not need to bear additional load stress during service.

[0041] Among them, the groove width of the rod groove 11 is greater than the width of the bushing boss 22, and the groove depth of the rod groove 11 is greater than the height of the bushing boss 22. Similarly, the groove width of the bushing groove 21 is greater than the width of the rod boss 12, and the groove depth of the bushing groove 21 is greater than the height of the rod boss 12. When the bushing is buckled on the bolt 1, it is convenient to insert the bushing boss 22 into the rod groove 11, and it is also convenient to buckle the bushing groove 21 on the rod boss 12 to form a clearance fit of the corresponding standard tolerance and basic deviation, and the clearance fit can also resist the influence of thermal expansion and contraction.

[0042] The cross-sectional shapes of the rod groove 11 and the rod boss 12 are both rectangular; the rectangular structure is relatively simple, easy to process and manufacture, reduces production costs, and improves processing efficiency. In other embodiments, it can also be a trapezoid or a triangle; but it is not limited to these shapes.

[0043] Among them, a plurality of bushing grooves 21 are processed along the axial direction on the inner wall of the bushing to form bushing bosses 22 between adjacent bushing grooves 21; here, the groove width and groove depth of adjacent bushing grooves 21 can be the same or different; similarly, the boss width and height of adjacent bushing bosses 22 can be the same or different; they can be adjusted according to the specific force conditions; but it should be noted that the size of the bushing groove 21 is in a corresponding relationship with the size of the rod boss 12, so that the two can be fully engaged; the size of the bushing boss 22 is in a corresponding relationship with the size of the rod groove 12, so that the two can be fully engaged; in this embodiment, in order to facilitate processing and manufacturing and save production and processing time, the groove width and groove depth of adjacent bushing grooves 21 and the width and height of adjacent bushing bosses 22 are the same.

[0044] Among them, the bushing boss 22 is buckled in the rod groove 11, and the bushing groove 21 is buckled in the rod boss 12, so that the bushing is buckled on the bolt 1; that is, the bushing is buckled on the bolt 1, the rectangular bushing groove 21 on the bushing is plugged with the rectangular rod boss 12 on the bolt 1, and the rectangular bushing boss 22 on the bushing is plugged with the rectangular rod groove 11 on the bolt 1; through the arrangement of the bushing boss 22 and the rod boss 12, the axial freedom of the bushing on the bolt 1 is limited, so that when subjected to external loads, the bushing cannot have axial displacement on the bolt 1. At the same time, the plug-in method of the rectangular groove and the rectangular boss, first, can provide precise positioning, ensure quick and accurate alignment during assembly, and reduce assembly errors. Second, through the close fit of the rectangular rod groove 11 and the rod boss 12, a stable connection can be achieved, enhancing the overall strength and reliability of the structure. Third, the rectangular rod groove 11 and the rectangular rod boss 12 transmit force through surface contact, which can effectively disperse the load and reduce stress concentration, thereby improving the stability and reliability of the structure; at the same time, they have a large contact area, can effectively resist lateral shear force, and enhance the shear resistance of the structure.

[0045] The end faces of the bushing and the nut 3 are both smooth, and will not cause wear to the end faces of the fastener 4 when in contact with the fastener 4 .

[0046] In other embodiments, there are at least two rod grooves 11 on the same cross section, and the portion between adjacent rod grooves 11 is a partitioned radial limiting boss 13 .

[0047] Among them, there are at least two rod grooves 11 on the same cross section, that is, the rod groove 11 on the same cross section is not a complete, continuous, closed annular groove. The purpose of this setting is to enable a radial limiting boss 13 to be formed between adjacent rod grooves 11 to limit the radial freedom of the bushing so that the bushing does not produce radial displacement when subjected to an external load.

[0048] Specifically, the arc length of the rod groove 11 is greater than the arc length of the radial limiting boss 13 .

[0049] In other embodiments, the rod bosses 12 arranged in parallel along the axial direction are connected via radial limiting bosses 13 .

[0050] Among them, each rod boss 12 arranged in parallel along the axial direction is connected by a radial limiting boss 13, that is, the width of the radial limiting boss 13 is consistent with the groove width of the rod groove 11, and they are evenly distributed in sequence. Therefore, it is not only beautiful and has uniform distribution of bearing capacity, but also can reduce processing difficulty and shorten processing time.

[0051] In other embodiments, the sleeve is a two-piece sleeve. When the two pieces of the sleeve are buckled together, the sleeve boss 22 at the joint is continuous.

[0052] In order to conveniently buckle the bushing onto the bolt 1 , the bushing is designed to be a two-petal type; the petal type bushing is also convenient for providing a bushing groove 21 on the inner wall.

[0053] When the two halves of the bushing are buckled together, the bushing boss 22 at the joint is continuous, that is, no bushing groove 21 is provided at the joint at the end of the bushing.

[0054] When the two halves of the bushing are buckled onto the bolt 1, a gap should be left between the end faces of the bushing; the gap formed between the end faces of the bushing can absorb vibration loads, reduce the risk of the nut being loosened, and also absorb additional stress caused by thermal expansion and contraction due to large changes in ambient temperature.

[0055] In other embodiments, there are at least two bushing bosses 22 on the same cross section, and the portion between the bushing bosses 22 is a partitioning groove 23 .

[0056] Among them, there are at least two bushing bosses 22 on the same cross-section, and the number of bushing bosses 22 is the same as the number of rod grooves 11; the part between the bushing bosses 22 is a partitioning groove 23, and the groove 23 on the bushing cooperates with the radial limiting boss 13 on the rod of the bolt 1 to limit the radial displacement of the bushing and avoid radial displacement under the action of external load.

[0057] In other embodiments, the groove 23 is communicated with the bushing grooves 21 arranged in parallel along the axial direction.

[0058] Among them, the groove 23 is connected with the bushing grooves 21 arranged in parallel along the axial direction, that is, the groove 23 on the bushing is connected with each bushing groove 21 arranged in parallel along the axial direction; the groove width of the groove 23 is the same as the width of the bushing boss 22, so the processing difficulty can be reduced and the processing time can be shortened; when cooperating with the limit boss 13 on the bolt 1, the vibration load is absorbed to reduce the risk of the nut being loosened.

[0059] In other embodiments, the nut 3 includes a load-bearing nut 31 and a locking nut 32 , and the rotation direction of the internal thread of the load-bearing nut 31 is opposite to that of the internal thread of the locking nut 32 .

[0060] The internal thread of the load-bearing nut 31 is opposite to the internal thread of the locking nut 32, that is, when the load-bearing nut 31 is a left-handed thread, the locking nut 32 is a right-handed thread; when the load-bearing nut 31 is a right-handed thread, the locking nut 32 is a left-handed thread. The load-bearing nut 31 and the locking nut 32 are a pair of left-handed and right-handed forward and reverse nuts, which are pressed together to form a pair of double-nut anti-loosening arrangements. When the vibration load causes the load-bearing nut to loosen and twist, the locking nut must be tightened and twisted with equal torque in the opposite direction under the action of the axial force, and the loosening and tightening torques offset each other to ensure long-term stable anti-loosening.

[0061] Among them, the thickness of the nut 3 should be greater than the axial length of the bushing, that is, the thickness of the load-bearing nut 31 is greater than the axial length of the load-bearing bushing 24, and the thickness of the locking nut 32 is greater than the axial length of the locking bushing 25; ensure that in the locked state, the bushing is completely covered by the nut 3 to avoid the bushing being partially exposed on the outside of the nut 3, resulting in the load-bearing nut 31 being screwed onto the load-bearing bushing 24 and the locking nut 32 being screwed onto the locking bushing 25, and the end faces of the load-bearing nut 31 and the locking nut 32 cannot be effectively tightened, which in turn causes the forces of the load-bearing nut 31 and the locking nut 32 with opposite rotation directions to fail to offset each other.

[0062] In other embodiments, the bushing includes a load-bearing bushing 24 and a locking bushing 25 , and the external thread direction of the load-bearing bushing 24 is opposite to that of the locking bushing 25 .

[0063] Among them, the load-bearing bushing 24 and the locking bushing 25 are a pair of bushings with opposite rotation directions. The bushings adopt a split design. On the one hand, it avoids setting the positive and negative threads on the same bolt, ensuring the strength of the thread while reducing the difficulty of processing; on the other hand, even when subjected to high torque, once the thread of the locking bushing 25 is damaged, it is only necessary to replace the bushing without replacing the bolt assembly as a set.

[0064] Processing method of the bushing: external threads are processed on the outer peripheral surface of the bushing. After the external threads are processed, the bushing is broken into two parts, and finally the bushing groove 21 and the groove 23 are processed on the inner wall of the bushing. This processing method greatly reduces the processing difficulty of the bushing and saves processing time.

[0065] To facilitate the distinction and selection, when the bushing and nut 3 are manufactured, the length of the bearing bushing 24 is greater than that of the locking bushing 25 , and the thickness of the bearing nut 31 is greater than that of the locking nut 32 .

[0066] In other embodiments, the bolt 1 includes a nut, and at least a portion of the rod of the bolt 1 near the nut is a bare rod, on which a fastener 4 is mounted. The rod groove 11 at least partially extends to the inner side of an inner hole of the fastener 4, and a bearing bushing 24 and a locking bushing 25 are mounted on the portion of the rod groove 11 where the fastener 4 is exposed. The bearing nut 31 is screwed onto the bearing bushing 24 to tighten the fastener 4, and the locking nut 32 is screwed onto the locking bushing 25 to tighten the bearing nut 31.

[0067] In a second aspect of the embodiment of the present application, there is provided an assembly method of an adjustable reverse threaded double nut anti-loosening bolt assembly, wherein the adjustable reverse threaded double nut anti-loosening bolt assembly is used, and the anti-loosening bolt assembly is used to lock a fastener 4; the assembly method comprises:

[0068] The bolt 1 passes through the fastener 4; the first set of bushings is placed close to the fastener 4 and buckled on the bolt 1, and then the corresponding nuts 3 are screwed into the first set of bushings and the fastener 4 is pressed; the second set of bushings is placed close to the end faces of the first set of nuts 3 and buckled on the bolt 1, and then the corresponding nuts 3 are screwed into the second set of bushings and the nuts 3 screwed on the first set of bushings are pressed.

[0069] The assembly method provided by the present application is simple and convenient, with a short assembly time and low technical requirements for operators; it is convenient for inspection and disassembly.

[0070] A more specific installation process is: the bolt 1 passes through the fastener 4, the fastener 4 is located on the bare rod part of the bolt 1, and at least part of the rod groove is located in the inner hole of the fastener 4; the two-piece load-bearing bushing 24 is buckled on the bolt 1 close to the fastener 4, and then the load-bearing nut 31 is screwed on the load-bearing bushing 24 to press the fastener 4; the two-piece locking bushing 25 is buckled on the bolt 1, where a gap is left between the end faces of the load-bearing bushing 24 and the end faces of the locking bushing 25, and then the locking nut 32 is screwed on the locking bushing 25 to press the load-bearing nut 31.

[0071] Although the bolt assembly provided in the present application uses the nut 3 to adjust the position to tighten the fastener 4, the screwing part of the nut and the bushing is guaranteed to have at least eight turns of thread to ensure a good uniform force effect.

[0072] It is easy for those skilled in the art to understand that the above-mentioned advantageous methods can be freely combined and superimposed without conflict.

[0073] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. An adjustable reverse thread double nut anti-loosening bolt assembly, characterized in that: include: A bolt (1), the bolt (1) comprising a rod, the outer peripheral surface of the rod being processed with a plurality of radial annular rod grooves (11) along the axial direction, so that radial annular rod bosses (12) are formed between adjacent rod grooves (11); A bushing, wherein the inner wall of the bushing is processed with a plurality of radial annular bushing grooves (21) along the axial direction, so that radial annular bushing bosses (22) are formed between adjacent bushing grooves (21); the bushing bosses (22) are buckled in the stem groove (11), and the bushing groove (21) is buckled on the stem bosses (12), so that the bushing is buckled on the bolt (1); The nut (3) has an inner hole axially processed with an internal thread, and the outer peripheral surface of the bushing is processed with an external thread matching the internal thread of the nut (3), so that the nut (3) can be screwed onto the bushing.

2. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 1, characterized in that: There are at least two rod grooves (11) on the same cross section, and the portion between adjacent rod grooves (11) is a partitioned radial limiting boss (13).

3. The adjustable reverse thread double nut anti-loosening bolt assembly according to claim 2, characterized in that: The rod bosses (12) arranged in parallel along the axial direction are connected respectively via the radial limiting bosses (13).

4. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 1, characterized in that: The bushing is of two-piece type. When the two halves of the bushing are buckled together, the bushing boss (22) at the joint is continuous.

5. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 4, characterized in that: There are at least two bushing bosses (22) on the same cross section, and the portion between the bushing bosses (22) is a partitioning groove (23).

6. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 5, characterized in that: The groove (23) is communicated with the bushing grooves (21) arranged in parallel along the axial direction.

7. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 1, characterized in that: The nut (3) comprises a load-bearing nut (31) and a locking nut (32), and the rotation direction of the internal thread of the load-bearing nut (31) is opposite to the rotation direction of the internal thread of the locking nut (32).

8. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 7, characterized in that: The bushing comprises a load-bearing bushing (24) and a locking bushing (25), and the external thread rotation direction of the load-bearing bushing (24) is opposite to the external thread rotation direction of the locking bushing (25).

9. The adjustable reverse threaded double nut anti-loosening bolt assembly according to claim 8, characterized in that: The bolt (1) comprises a nut, the shank of the bolt (1) being at least partially a bare shank near the nut, a fastener (4) being mounted on the bare shank, the shank groove (11) at least partially extending to the inner side of an inner hole of the fastener (4), a bearing bushing (24) and a locking bushing (25) being mounted on the portion of the shank groove (11) exposed from the fastener (4), the bearing nut (31) being screwed onto the bearing bushing (24) to press the fastener (4), and the locking nut (32) being screwed onto the locking bushing (25) to press the bearing nut (31).

10. An assembly method of an adjustable reverse threaded double nut anti-loosening bolt assembly, characterized in that: An adjustable reverse-threaded double-nut anti-loosening bolt assembly according to any one of claims 1 to 9 is used to lock a fastener (4); the assembly method comprises: The bolt (1) passes through the fastener (4); the first set of bushings is placed close to the fastener (4) and snapped onto the bolt (1); then the corresponding nut (3) is screwed into the first set of bushings and the fastener (4) is pressed; the second set of bushings is placed close to the end face of the nut (3) of the first set and snapped onto the bolt (1); then the corresponding nut (3) is screwed into the second set of bushings and the nut (3) screwed onto the first set of bushings is pressed.

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