Double-screwing-direction bolt locking device

Abstract

The invention belongs to the technical field of fasteners, and relates to a double-screwing-direction bolt anti-loosening device which comprises a double-screwing-direction bolt, a locking nut and an anti-loosening nut, internal threads of the locking nut and internal threads of the anti-loosening nut are matched with the double-screwing-direction bolt, and a conical groove of the anti-loosening nut is matched with a belleville spring washer of the locking nut. The belleville spring washer is arranged on the bolt, so that the belleville spring washer is drawn close to the axis of the bolt in the radial direction, friction between the belleville spring washer and the locking nut and friction between the belleville spring washer and the locking nut are increased, meanwhile, stable pre-tightening force can be provided, and when the belleville spring washer is impacted and vibrated, the buffering and vibration absorbing capacity can effectively reduce the loosening tendency of the nut.

Description

Technical Field

[0001] The invention belongs to the technical field of fasteners, and in particular relates to a double-rotation bolt anti-loosening device. Background Art

[0002] Bolts and nuts are the most common fasteners in mechanical connections, used to fasten two or more parts together. They work together through threads to form a detachable connection system. When bolts and nuts are used in combination, the nuts are screwed into the threads on the bolts, and a preload is generated by applying torque to ensure that the connection parts fit tightly and prevent loosening and separation caused by vibration. Loose bolts and nuts may bring a series of safety hazards and technical problems, especially in structures subjected to high loads or dynamic stress. Loose bolts and nuts may reduce structural strength, increase vibration and noise, cause safety accidents, affect equipment performance, shorten service life, and other harmful consequences.

[0003] At present, the methods of preventing bolts and nuts from loosening are mainly divided into two categories: friction-proof nuts and mechanical-proof nuts. Friction-proof nuts prevent loosening by generating a positive pressure between the locking nut pair that does not change with external force, thereby generating a friction force that can prevent the relative rotation of the locking nut pair. For example, the use of elastic washers, double nuts and other structural forms is more convenient during disassembly. Mechanical-proof nuts use locking nut stops to directly limit the relative rotation of the locking nut pair to achieve the purpose of preventing loosening. Common structures include cotter pins, serial steel wires and stop washers. Because it uses stops to directly limit the relative rotation of the threaded pair, it has certain advantages in preventing loosening.

[0004] However, the anti-loosening nuts in the prior art still have certain limitations in terms of vibration resistance, impact resistance and anti-loosening effects, and cannot fully meet the needs of high-strength and high-reliability connections. Specifically, when friction anti-loosening nuts are faced with impact, vibration, and variable load conditions, the bolts will initially loosen and the preload will decrease. As the vibration frequency continues to accumulate, the preload loss will slowly increase, which may eventually cause the nuts to loosen, and then cause the threaded connection to fail, posing a hidden danger to the normal operation of the equipment; while mechanical anti-loosening nuts are extremely inconvenient to disassemble, which undoubtedly increases the maintenance workload and related costs, and brings many inconveniences to the maintenance of the equipment.

[0005] Therefore, a device or method is needed to solve the above technical problems by effectively solving the problem that nuts are easily loosened when subjected to impact for a long time and ensuring that disassembly, maintenance and use are more convenient. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a double-twist bolt anti-loosening device, comprising: a double-twist bolt, a locking nut, and an anti-loosening nut. The screw of the double-twist bolt is in the shape of a stepped shaft with radial dimensions increasing successively from the bolt head to the bolt tail. The outer cylindrical surface of the small radial axis of the double-twist bolt is provided with a first external thread, and the outer cylindrical surface of the large radial axis of the double-twist bolt is provided with a second external thread. The first external thread and the second external thread have opposite rotation directions. The two external threads on the screw have opposite rotation directions while the two internal threads of the two nuts have the same rotation direction. Therefore, when the two nuts are tightened, the axial stress generated by the deformation and extrusion between the internal and external threads causes the end faces of the two nuts to be squeezed toward each other, thereby increasing the pressure between the two nuts and then increasing the friction between the end faces of the two nuts, thereby preventing loosening.

[0007] The inner thread of the locking nut matches the second outer thread, and the end surface of the locking nut protrudes outward in the axial direction and is provided with a disc spring washer, the disc spring washer is provided with elasticity that can be contracted and expanded in the radial direction, and the disc spring washer is fixedly connected to the locking nut or manufactured integrally with the locking nut;

[0008] The internal thread of the anti-loosening nut matches the first external thread, and the end face of the anti-loosening nut is provided with a cylindrical groove which is axially inwardly concave and coaxial with the anti-loosening nut, and the inner circumference of the groove is axially provided with a taper with a larger outer opening and a smaller inner opening, the radial dimension of the groove opening is larger than the outer diameter of the disc spring washer, the radial dimension of the groove bottom is smaller than the outer diameter of the disc spring washer, and the groove depth of the groove is not greater than the axial height of the disc spring washer;

[0009] When the anti-loosening nut is rotated on the double-rotation bolt and tightened against the locking nut, the groove radially presses the disc spring washer to the outer circumference of the screw of the double-rotation bolt; when the locking nut and the anti-loosening nut are ready to be tightened, since the inner wall of the groove is conical and the disc spring washer is elastically deformable in the radial direction, therefore, when the anti-loosening nut is pressed against the locking nut, the inner wall of the groove gradually squeezes the disc spring washer radially inward, so that the disc spring washer radially moves closer to the axis of the bolt, and the disc spring washer increases the friction between the locking nut and the anti-loosening nut while providing a stable pre-tightening force, and when subjected to impact and vibration, its buffering and vibration absorption capacity can effectively reduce the loosening tendency of the nut.

[0010] Preferably, the disc spring washer is composed of a plurality of circumferentially distributed ribs arranged along the axial direction, wherein one end of the rib close to the locking nut is circumferentially fixedly connected, and one end of the rib away from the locking nut is suspended in the air; the manner in which one end of the rib is fixedly connected to the locking nut and the other end is suspended in the air makes the rib have better elasticity and deformation recovery force, making the nut not easy to loosen, effectively preventing the nut from loosening due to vibration or impact.

[0011] Preferably, the inner ring of the disc spring washer is provided with an internal thread that matches the second external thread; the internal thread of the inner ring of the disc spring washer increases the friction area between the washer and the nut and bolt, increases the friction between the nut and the connecting part, makes the nut not easy to loosen, and effectively prevents the nut from loosening due to vibration or impact.

[0012] Preferably, a disc spring washer is provided on one side end face of the locking nut, and a groove is provided on one side end face of the anti-loosening nut; the groove or disc spring washer provided on one side end face makes the cost of processing the nut lower while preventing the bolt from loosening, and is therefore suitable for large-scale processing or application scenarios using anti-loosening bolts.

[0013] Preferably, a locking groove is provided on the end face of the locking nut, and an axially retractable stop pin is provided on the end face of the anti-loosening nut facing the locking nut, and the pin head of the stop pin extends out of the end face of the anti-loosening nut, and the pin head of the stop pin matches the locking groove; through the cooperation between the stop pin and the locking groove, the anti-loosening nut and the locking nut are connected as a whole without causing angular displacement, and because the two external threads on the screw have opposite rotation directions and the two internal threads of the two nuts have the same rotation direction, the nut can be effectively prevented from loosening from the bolt, thereby improving the anti-loosening performance of the thread pair.

[0014] More preferably, there are multiple locking grooves, and the multiple locking grooves are radially distributed along the radial direction; the multiple locking grooves and the radial distribution make it easier for the retaining pin and the locking groove to find a matching position when the two nuts are being tightened. Even if there is no suitable pinning position during tightening, when the nut is loosened due to external vibration or impact, the locking nut and the anti-loosening nut only need to rotate a small angle with each other to encounter the matching position of the retaining pin and the locking groove. The retaining pin is pressed into the locking groove by a spring to achieve pinning, which can still effectively prevent the nut from loosening from the bolt, thereby improving the anti-loosening performance of the threaded pair.

[0015] More preferably, the anti-loosening nut is provided with a pin hole, a compressed spring is provided in the pin hole, the anti-retraction pin can be telescopically slid in the pin hole, one end of the spring is connected to the pin hole, and the other end of the spring is connected to the root of the anti-retraction pin.

[0016] More preferably, the axial cross-section of the pin head of the stop pin is a right-angled trapezoid or a right-angled triangle, the right-angled surface of the stop pin faces the direction of loosening the locking nut, and the beveled surface of the stop pin faces the direction of tightening the locking nut; the right-angled surface of the stop pin faces the direction of loosening the locking nut, and when the nut is loosened due to external vibration or impact, the right-angled surface clamps the locking groove to prevent the nut from loosening; the beveled surface of the stop pin faces the direction of tightening the locking nut, and when the operator tightens the nut, the beveled surface is blocked by the locking groove and an axial component force is generated. The spring behind the stop pin is compressed through the stop pin, so that the stop pin exits the locking groove to facilitate the operator to perform the tightening operation. When the tightening operation is completed, the spring force pushes the stop pin toward the locking groove side. Once the stop pin and the locking groove meet the matching position, the spring presses the stop pin into the locking groove again to achieve pin insertion, which can still effectively prevent the nut from loosening from the bolt, thereby improving the anti-loosening performance of the threaded pair.

[0017] More preferably, the pin hole is a through hole, and a plug cover with an anti-corrosion function is detachably connected to the hole on the side of the pin hole away from the locking nut, and the inner end of the plug cover is against the inner end of the spring; a sealing ring is added at the contact position between the plug cover and the nut hole to further improve the sealing performance and effectively prevent corrosive media from penetrating from the gap, which is suitable for bolt protection with high sealing requirements; the inner side of the plug cover is designed with a thread matching the inner diameter of the through hole, and is screwed on the nut through the thread, which is firmly connected and not easy to fall off, and can provide a good sealing effect; a tight fit design is adopted between the inner diameter of the plug cover and the inner diameter of the through hole, and a close fit is achieved by relying on the elasticity or plastic deformation of the material, thereby achieving the purpose of sealing and protection; the plug cover cooperates with the through hole, which is convenient for setting and adjusting the preload force of the spring in the early stage and for inspecting and maintaining the spring and the stop pin in the later stage, so as to set the spring elastic force and inspect and maintain the loose bolts according to different occasions and different needs. The use of anti-corrosion plug covers can effectively extend the service life of the nuts and reduce maintenance costs.

[0018] More preferably, an elastic rubber ring is provided between the inner end of the plug cover and the inner end of the spring; the flat side of the elastic rubber ring is caught by the bottom end surface of the spring hole of the anti-loosening nut, so that the retaining pin continues to maintain a normal working state when the spring fails.

[0019] The beneficial effects of the present invention are:

[0020] 1. The present invention cooperates the conical groove of the anti-loosening nut with the disc spring washer of the locking nut, so that the disc spring washer is radially close to the axis of the bolt. The disc spring washer increases the friction between the locking nut and the anti-loosening nut and can provide a stable pre-tightening force. When subjected to impact and vibration, its buffering and vibration absorption ability can effectively reduce the loosening tendency of the nut.

[0021] 2. The present invention cooperates the elastically retractable retaining pin on the anti-loosening nut with the radially distributed locking grooves of the locking nut, so that the retaining pin can withdraw from the locking groove during the tightening operation. When the nut is loosened due to external vibration or impact, the retaining pin is pressed into the locking groove by the spring to effectively prevent the nut from loosening from the bolt and improve the anti-loosening performance of the threaded pair. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural principle assembly diagram of a double-rotation bolt anti-loosening device of the present invention;

[0023] Figure 2 It is a schematic diagram of the double-rotation bolt structure of the present invention;

[0024] Figure 3 It is a three-dimensional schematic diagram of the locking nut and the anti-loosening nut of the present invention;

[0025] Figure 4 It is a part diagram of the locking nut of the present invention;

[0026] Figure 5 It is a part diagram of the anti-loosening nut of the present invention;

[0027] Figure 6 It is a part diagram of a stop pin of the present invention;

[0028] Figure 7 It is the plug cover parts diagram of the present invention;

[0029] Figure 8 It is the elastic rubber ring parts diagram of the present invention.

[0030] In the figure, 1. double-twist bolt; 2. locking nut; 3. anti-loosening nut; 4. first external thread; 5. second external thread; 6. disc spring washer; 7. groove; 8. taper; 9. rib; 10. locking groove; 11. stop pin; 12. pin hole; 13. spring; 14. plug cover; 15. elastic rubber ring. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technologies in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figures 1 to 8 As shown, the double-rotation bolt anti-loosening device of this embodiment includes: a disc spring washer 6, a locking nut 2, a spring washer and an anti-loosening nut 3.

[0033] The disc spring washer 6 is combined with the lock nut 2, and the disc spring washer 6 can enhance its ability to withstand impact force. When used, the disc spring washer 6 is first placed in the ring of the lock nut 2, and then expanded through the ring to form a cone, so as to achieve the effect of not being easy to fall off.

[0034] The disc spring washer 6 has the advantages of high rigidity, strong buffering and vibration absorption capacity, and can bear large loads with small deformation. During the nut tightening process, the disc spring washer 6 can provide a stable pre-tightening force, and at the same time, when subjected to impact and vibration, its buffering and vibration absorption capacity can effectively reduce the loosening tendency of the nut.

[0035] The fastening nut 2 is combined with the disc spring washer 6, and the double nuts are interlocked to prevent themselves from loosening, thereby enhancing the locking effect.

[0036] The spring washer and the anti-loosening nut 3 are used to further limit the loosening of the nut and improve the stability of the connection.

[0037] A spring 13 and a stop pin 11 are provided inside the anti-loosening nut 3. The spring 13 and the stop pin 11 cooperate with each other to form a double-rotation locking structure through the combination of the forward and reverse double-threaded screw and the left-handed threaded nut and the right-handed threaded nut.

[0038] The anti-loosening nut 3 and the locking nut 2 form an interlocking bidirectional nut. The anti-loosening nut 3 is composed of a nut body, an elastic rubber ring 15, a spring 13, a stop pin 11, etc. The nut body has an internal thread, the lower end is an inner cylinder, and the inner side has a corresponding thread to connect with the locking nut 2. The elastic rubber ring 15 is located inside the nut to provide elasticity and friction to help prevent loosening. The spring 13 works with the elastic rubber ring 15 to provide continuous pressure to enhance the anti-loosening effect. The stop pin 11 is used to limit the axial movement of the nut to ensure that it is fixed in place. The locking nut 2 is composed of a nut body, a locking component, etc. The upper end of the nut body is a locking component, which is a cylinder, consistent with the inner cylinder of the anti-loosening nut 3, and the outer side has a plurality of evenly distributed threads, and the inner thread is consistent with the inner thread of the anti-loosening nut 3.

[0039] The locking nut 2 is tightly matched with the anti-loosening nut 3, and when the spring 13 inside the anti-loosening nut 3 applies pressure, the locking nut 2 will be tightly pressed on the anti-loosening nut 3. This close contact increases the friction between the two, thereby preventing the bolt from loosening.

[0040] The nut in this embodiment is equipped with a disc spring washer 6. When tightened, the disc spring washer 6 changes from a cone to a plane, and the ribs 9 or serrated patterns on its surface extend into the tightening side, increasing the friction between the nut and the connector, making the nut difficult to loosen, and effectively preventing the nut from loosening due to vibration or impact. The disc spring washer 6 has a certain elasticity, can absorb and relieve vibration and impact, protect the connector and equipment from damage, and thus maintain the reliability of the connection under a vibration environment.

[0041] This embodiment uses the double nut interlocking method to prevent the nut itself from loosening, thereby enhancing its locking effect. After the double nuts are tightened, the axial force generated between the nuts will increase the friction between the nut teeth and the bolt teeth, thereby effectively preventing the nuts from automatically loosening. When subjected to external vibration loads, due to the force between the two nuts, thread self-loosening can only occur at the interface between a single nut and the supporting surface, and self-locking is formed between the two nuts, thereby improving the anti-loosening performance of the thread pair.

[0042] The combination of the forward and reverse double-threaded screw and the left-handed threaded nut and the right-handed threaded nut in this embodiment: through the ingenious combination of the forward and reverse double-threaded screw and the left-handed threaded nut and the right-handed threaded nut, the two are relatively fixed to form an interlocking body, and finally achieve two-way locking, further enhancing the anti-loosening effect.

[0043] The bolts in this embodiment adopt a double-rotation design, and the rotation directions of the two threads are opposite. A plurality of square grooves are provided on the locking nut 2. The thread rotation direction of the locking nut 2 is the same as the thread rotation direction of the larger nominal diameter of the double-rotation bolt. The thread rotation direction of the anti-loosening nut 3 is the same as the thread rotation direction of the smaller nominal diameter of the double-rotation bolt. A threaded hole is drilled in the anti-loosening nut 3, and a retaining pin 11 and a spring 13 are installed in the hole. The spring is supported by a plug cover 14. The plug cover 14 is threaded and tightened on the pin hole 12. One end of the retaining pin 11 is cylindrical, and the other end is beveled at a certain angle.

[0044] After the locking nut 2 is tightened, when the anti-loosening nut 3 is installed, when the anti-loosening nut 3 contacts the locking nut 2, the retaining pin 11 automatically pops out under the action of the spring 13 when it encounters the square groove on the tightening nut 3. Since it is beveled at a certain angle, it can slide and be pushed back into the installation hole when it encounters the side wall of the square groove. Until the anti-loosening nut 3 is tightened. If the anti-loosening nut 3 tries to loosen after tightening, since the other side of the retaining pin 11 is not beveled at an angle, it is tightly stuck in the square groove of the locking nut 2, so that it cannot move back. In this way, the two nuts are tightly connected together. In the anti-loosening nut 3, the spring 13 is connected to the elastic rubber ring 15, and the elastic rubber ring 15 supports the retaining pin 11. As shown Figure 7As shown, the plane side of the elastic rubber ring 15 is fixedly connected with the spring 13. When the anti-loosening nut 3 is installed, the anti-retraction pin 11 is stuck in the square groove of the locking nut 2. In order to prevent the spring 13 from failing due to excessive time, the plane side of the elastic rubber ring 15 is stuck by the bottom end face of the pin hole 12 of the anti-loosening nut 3, so that the anti-retraction pin 11 continues to maintain a normal working state.

[0045] When the locking nut 2 tends to loosen, since its thread rotation direction is opposite to that of the anti-loosening nut 3, the power of its loosening tendency will make the anti-loosening nut 3 tighter. Similarly, when the anti-loosening nut 3 tends to loosen, its loosening tendency will make the locking nut 2 tighter. In this way, the anti-loosening requirement is achieved.

[0046] The lock nut 2 and the anti-loosening nut 3 match: the lock nut 3 has a protruding cylinder, the internal thread specification of which is consistent with the lock nut 3, and there is an open square groove to allow the remaining part to have a certain degree of elasticity. The anti-loosening nut 3 has a stepped hole, such as Figure 5 As shown. The large diameter part of the stepped hole is a light hole, but has a certain taper: that is, the diameter of the mouth is large and the diameter of the bottom is small. The thread specification of the small diameter part of the stepped hole is consistent with the corresponding bolt. When the two are used in pairs, the large diameter part of the anti-loosening nut 3 matches the protruding part of the locking nut 2, and the anti-loosening nut 3 squeezes the protruding part of the locking nut 2, so that the protruding part of the locking nut 2 holds the bolt tightly, thereby increasing the friction between the nut and the bolt, and enhancing the anti-loosening effect.

[0047] In this embodiment, the disc spring washer 6 cooperates with the nut: the disc spring washer 6 cooperates with the nut to prevent point contact under dynamic stress, so that the nut can withstand greater impact force and ensure that the fastener will not loosen.

[0048] This embodiment adopts the form of upper and lower double nuts, that is, after the locking nut 2 is tightened, the anti-loosening nut 3 is tightened separately, and double interlocking is achieved by changing the pitch and the center axis of the nut to ensure that the nut will not loosen after installation, thereby improving the reliability and safety of the connection.

[0049] The threaded connection pair in the double-rotation bolt of this embodiment not only overcomes the disadvantage of the common standard connection pair that is easy to loosen under vibration conditions, but also prolongs the service life. This special anti-loosening method can be disassembled repeatedly, and the anti-loosening function still exists permanently. This anti-loosening method has the characteristics of high vibration resistance, lightness, and repeatable disassembly.

[0050] The nut installation method of the double-rotation bolt in this embodiment is consistent with that of an ordinary nut, no additional accessories are added and no additional installation tools are required, and the overall installation process is simple.

[0051] Example

[0052] Example 1

[0053] The double-rotation bolt anti-loosening technology of the present invention comprises a disc spring washer 6, a locking nut 2, a spring washer and an anti-loosening nut 3, which helps to improve the anti-loosening performance of the connection structure.

[0054] The connection structure includes: a locking nut 2, the locking nut 2 is threadedly connected with a locking nut 3, a spring 13 and a stop pin 11 are arranged inside the locking nut 3, and the spring 13 and the stop pin 11 cooperate to form a bidirectional locking structure with the locking nut 2. The locking nut 3 is a double nut structure, which increases the contact strength with the bolt body, thereby reducing the probability of it loosening due to vibration.

[0055] The cross section of the lock nut body is a regular hexagon.

[0056] The extension section has a through hole inside and a plurality of opening slots are symmetrically provided on the extension section, and the opening slots divide the extension section into a corresponding number of locking petals, so as to prevent the nut from loosening during long-term vibration.

[0057] The height of the locking flap is less than or equal to the height of the extension section. The inner wall surface of the locking flap is provided with anti-skid threads. The anti-skid thread structural design can improve the anti-loosening performance of the locking flap, thereby improving the anti-loosening performance of the entire slotted nut.

[0058] The disc spring washer 6 helps to balance the preload loss caused by deformation and creep during bolt and nut assembly, and at the same time has sufficient elasticity to increase the overall elastic force of the connection pair. The inherent elastic force can compensate for the preload loss, meet the clamping force requirements, and ensure the reliability of the connection pair.

[0059] In practical applications, the disc spring washer 6 is first placed in the annular part of the locking nut 2, and then expanded into a cone through the annular part, so that the disc spring washer 6 is combined with the locking nut 2. Next, the spring washer and the lock nut 3 are installed in place. On the parts to be connected, the locking nut 2 is first installed, and then the lock nut 3 is installed, so that the extrusion part of the lock nut 3 and the locking part of the locking nut 2 cooperate with each other to achieve interlocking between the nuts. Through this structural design, the double-rotation bolt anti-loosening technology can effectively solve the problem that the nut is easy to loosen when subjected to impact for a long time, improve the reliability and safety of the connection, and is suitable for various high-strength and high-reliability connection occasions.

[0060] To summarize, the present invention cooperates the conical groove of the anti-loosening nut with the disc spring washer of the locking nut, and the elastically retractable stop pin on the anti-loosening nut cooperates with the radially distributed locking grooves of the locking nut, thereby effectively solving the problem that the nut is easy to loosen when subjected to impact for a long time, while ensuring that disassembly, maintenance and use are more convenient.

[0061] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A double-rotation bolt anti-loosening device, characterized in that: include: A double-rotation bolt (1), a locking nut (2), and a locking nut (3); the screw of the double-rotation bolt (1) is in the shape of a stepped shaft with radial dimensions increasing in sequence from the bolt head to the bolt tail; the outer cylindrical surface of the small radial axis of the double-rotation bolt (1) is provided with a first external thread (4); the outer cylindrical surface of the large radial axis of the double-rotation bolt (1) is provided with a second external thread (5); the first external thread (4) and the second external thread (5) have opposite rotation directions; The internal thread of the locking nut (2) matches the second external thread (5); the end surface of the locking nut (2) protrudes outward in the axial direction and is provided with a disc spring washer (6); the disc spring washer (6) is provided with elasticity that can be contracted and expanded in the radial direction; the disc spring washer (6) is fixedly connected to the locking nut (2) or is manufactured integrally with the locking nut (2); The internal thread of the anti-loosening nut (3) matches the first external thread (4), the end face of the anti-loosening nut (3) is provided with a cylindrical groove (7) which is axially inwardly recessed and coaxial with the anti-loosening nut (3), the inner circumference of the groove (7) is axially provided with a taper (8) with a larger outer opening and a smaller inner opening, the radial dimension of the groove (7) notch is larger than the outer diameter of the disc spring washer (6), the radial dimension of the groove bottom of the groove (7) is smaller than the outer diameter of the disc spring washer (6), and the groove depth of the groove (7) is not greater than the axial height of the disc spring washer (6); When the anti-loosening nut (3) is rotated on the double-rotation bolt (1) to tighten against the locking nut (2), the groove (7) presses the disc spring washer (6) radially to the outer circumference of the screw of the double-rotation bolt (1).

2. A double-rotation bolt anti-loosening device according to claim 1, characterized in that: The disc spring washer (6) is composed of a plurality of ribs (9) arranged axially and distributed around the circumference. One end of the rib (9) close to the locking nut (2) is fixedly connected around the circumference, and one end of the rib (9) away from the locking nut (2) is suspended.

3. A double-rotation bolt anti-loosening device according to claim 1, characterized in that: The inner ring of the disc spring washer (6) is provided with an internal thread matching the second external thread (5).

4. A double-rotation bolt anti-loosening device according to claim 1, characterized in that: A disc spring washer (6) is arranged on one end surface of the locking nut (2), and a groove (7) is arranged on one end surface of the anti-loosening nut (3).

5. A double-rotation bolt anti-loosening device according to claim 1, characterized in that: The end surface of the locking nut (2) is provided with a locking groove (10), and the end surface of the anti-loosening nut (3) facing the locking nut (2) is provided with a stop pin (11) that can be retracted along the axial direction, and the pin head of the stop pin (11) extends out of the end surface of the anti-loosening nut (3), and the pin head of the stop pin (11) matches the locking groove (10).

6. A double-rotation bolt anti-loosening device according to claim 5, characterized in that: A plurality of locking grooves (10) are provided, and the plurality of locking grooves (10) are radially distributed along the radial direction.

7. A double-rotation bolt anti-loosening device according to claim 5, characterized in that: The anti-loosening nut (3) is provided with a pin hole (12), a compressed spring (13) is provided in the pin hole (12), the anti-retraction pin (11) can be telescopically slid in the pin hole (12), one end of the spring (13) is connected to the pin hole (12), and the other end of the spring (13) is connected to the root of the anti-retraction pin (11).

8. A double-rotation bolt anti-loosening device according to claim 7, characterized in that: The axial cross-section of the pin head of the retaining pin (11) is a right-angled trapezoid or a right-angled triangle, the right-angled surface of the retaining pin (11) faces the direction of loosening the locking nut (2), and the oblique-angled surface of the retaining pin (11) faces the direction of tightening the locking nut (2).

9. A double-rotation bolt anti-loosening device according to claim 7, characterized in that: The pin hole (12) is a through hole, and a plug cover (14) is detachably connected to the hole opening of the pin hole (12) on the side away from the locking nut (2), and the inner end of the plug cover (14) abuts against the inner end of the spring (13).

10. A double-rotation bolt anti-loosening device according to claim 9, characterized in that: An elastic rubber ring (15) is also provided between the inner end of the plug cover (14) and the inner end of the spring (13).

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