Corrugated pipe type variable-pitch self-locking nut

By adopting the form of a tapered variable pitch bellows in the nut fastener, and the rotation torque of the non-equal pitch conical threads is used to cause axial and radial deformation of the bellows body of the installed nut, it solves the problem that existing nut fasteners are difficult to prevent loosening under high vibration and high load conditions, and achieves a larger bonding area and a larger locking force.

CN120027124APending Publication Date: 2025-05-23苗春才
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202311571680.8
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2023-11-22
Publication Date
2025-05-23

AI Technical Summary

Technical Problem

Existing nut fasteners are difficult to effectively prevent loosening under high vibration and high load conditions, especially in the fields of high-speed rail trains, the locking force of the existing technology is insufficient and it is difficult to meet the strict application needs.

Method used

The form of a bellows with a conical variable pitch is adopted. The inner conical thread of the lock nut and the outer conical thread of the bellows of the installation nut is tightened. By causing the part of the bellows of the installation nut to deform the axial and radial direction of the bellows of the installation nut to prevent the locking and anti-loosening.

Benefits of technology

Through the rotation torque of the unequal pitch conical thread, the tensile compression force between the threads is significantly increased. The bonding area of ​​the corrugated tube variable pitch self-locking nut is larger, the deformation is greater, and the locking force is greater, which effectively prevents loosening.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN120027124A_ABST
    Figure CN120027124A_ABST
Patent Text Reader

Abstract

The invention relates to the technical field of plane universal synchronous transmission machinery. A corrugated pipe type variable-pitch self-locking nut is characterized by mainly comprising a mounting nut (1), a locking nut (2), a locking nut internal thread (3), a mounting nut external thread (4), a mounting nut internal thread (5) and a corrugated pipe body (6). According to the technology, the form of a conical variable-pitch corrugated pipe body (6) is adopted, in the process that a locking nut internal thread (3) and a mounting nut external thread (4) on the corrugated pipe body (6) of a mounting nut (1) are matched and screwed, the corrugated pipe body (6) deforms in the axial direction and the radial direction, the pressure between the thread face of the mounting nut internal thread (5) and the thread face of a bolt is large, and then locking and looseness prevention are achieved. Due to the effect of the spiral torsion structure on torque amplification, the corrugated pipe type variable-pitch self-locking nut is larger in combination area, larger in deformation force and larger in locking force compared with a Japanese Hardellok nut.
Need to check novelty before this filing date? Find Prior Art

Description

[0001] Technical field: The present invention relates to the technical field of nut fasteners. At present, the world's double-nut locking method includes the Japanese Hardlock nut. The Japanese Hardlock nut is locked by combining the convex and concave surfaces of an eccentric cone. It is said to be a nut that never loosens. It has been verified in European laboratories. The anti-loosening effect of the nut is world-leading. It is used in high-speed trains and fields with relatively large mechanical vibrations. My solution is to use a conical variable pitch bellows form. During the process of tightening the inner conical thread of the locking nut and the outer conical unequal pitch thread of the bellows body of the mounting nut, the axial and radial deformation of the bellows body of the mounting nut occurs (the bellows body is prone to radial and axial deformation), thereby locking and preventing loosening. The rotational torque of the unequal pitch conical thread can amplify the tensile and compressive forces between the threads many times. The bellows-type variable pitch self-locking nut has a larger bonding area, greater deformation, and greater locking force than the Hadlock nut.

[0002] Background technology: Tapered threads are used in pipe threads and drill chucks to improve the binding force. The installation nut and the locking nut have different pitches, and the bellows body is easily compressed and stretched in the axial and radial directions. When tightened, the rotational torque of the unequal pitch tapered threads can amplify the tensile and compressive forces between the threads many times, which has a very large compression and tensile force on the bellows body.

[0003] Invention content: The mounting nut adopts internal and external double threads, and the external thread adopts straight thread or tapered thread; the locking nut adopts internal straight thread or internal tapered thread, and the locking nut can be tightened on the mounting nut by rotation, the internal thread tip of the mounting nut and its external thread root are radially opposite to each other, and the internal thread root of the mounting nut and its external thread tip are radially opposite to each other, and the internal and external threads constitute a body similar to the shape of a bellows.

[0004] When the internal thread of the locking nut and the external thread of the mounting nut are both straight threads, the pitch of the internal thread of the locking nut and the external thread of the mounting nut are not equal, or the pitch of the external thread of the mounting nut itself is a variable pitch. When the internal thread of the locking nut and the external thread of the mounting nut are tightened together, the internal thread of the locking nut will produce axial tensile force or contraction force on the bellows body part of the mounting nut, and the bellows body part of the mounting nut will be stretched or compressed in the axial direction. The thread pitch of the bellows body part of the mounting nut changes, and the thread tooth surface of the external thread of the bellows body part of the mounting nut is strengthened with the internal thread tooth surface of the locking nut and the external thread tooth surface of the bolt, thereby increasing the friction force.

[0005] When the internal thread of the locking nut and the external thread of the mounting nut are both tapered threads with equal pitches, a wedge force is generated during the process of tightening the locking nut on the mounting nut, which will cause the bellows body portion formed by the internal and external threads of the mounting nut to shrink and deform radially inward, and the bonding force between the thread tooth surface of the bellows body portion of the mounting nut and the internal thread tooth surface of the locking nut and the external thread tooth surface of the bolt is enhanced, thereby increasing the friction force.

[0006] When the inner thread of the locking nut and the outer thread of the mounting nut are both tapered threads with different pitches, a wedge force is generated during the process of tightening the locking nut on the mounting nut, causing the bellows body to contract radially inward; and an axial tensile or compressive force is also generated, causing the bellows body to be stretched or compressed axially. At this time, the thread surface of the thread of the bellows body of the mounting nut has a stronger bonding force with the inner thread surface of the locking nut and the outer thread surface of the bolt, and the friction force is greater. Description of the drawings:

[0007] Figure 1 . Schematic diagram of bellows type variable pitch self-locking nut

[0008] The present invention is described in detail below with reference to the accompanying drawings.

[0009] like Figure 1 As shown, the bellows type variable pitch self-locking nut is composed of a mounting nut (1), a locking nut (2), an inner thread of the locking nut (3), an outer thread of the mounting nut (4), an inner thread of the mounting nut (5), and a bellows body (6).

[0010] like Figure 1 As shown, the external thread (4) of the mounting nut (1) is a tapered thread, and the internal thread (5) of the mounting nut is a straight thread;

[0011] The inner thread (3) of the locking nut adopts a tapered thread;

[0012] The lock nut (2) can be tightened onto the mounting nut (1) by rotating it.

[0013] like Figure 1 As shown, the tooth tip of the internal thread (5) of the mounting nut and the tooth root of the external thread (4) of the mounting nut are radially opposite to each other, the tooth root of the internal thread (5) of the mounting nut and the tooth tip of the external thread (4) of the mounting nut are radially opposite to each other, and the internal and external threads form a bellows body (6) similar to the shape of a bellows, and the bellows body (6) is easily stretched and compressed.

[0014] like Figure 1 As shown, when the locking nut internal thread (3) and the mounting nut external thread (4) are both straight threads, the locking nut internal thread (3) and the mounting nut external thread (4) have different pitches. When the locking nut internal thread (3) and the mounting nut external thread (4) are tightened together, the locking nut internal thread (3) will generate an axial tensile force or a contraction force on the mounting nut (1) bellows body (6) portion, and the bellows body (6) portion of the mounting nut (1) will be stretched or compressed in the axial direction. The thread pitch of the bellows body (6) portion of the mounting nut (1) changes, and the thread tooth surface of the bellows body (6) portion of the mounting nut (1) is strengthened in combination with the thread tooth surface of the locking nut internal thread (3) and the bolt external thread tooth surface, thereby increasing the friction force.

[0015] like Figure 1 As shown, when the locking nut internal thread (3) and the mounting nut external thread (4) are both tapered threads with equal pitches, a wedge force is generated during the process of tightening the locking nut (2) on the mounting nut (1), which will cause the portion of the bellows body (6) in the mounting nut (1) to shrink and deform radially inward, and the bonding force between the thread surface of the mounting nut external thread (4) of the bellows body (6) of the mounting nut (1) and the thread surface of the locking nut internal thread (3), the thread surface of the mounting nut internal thread (5) and the thread surface of the bolt external thread is enhanced, thereby increasing the friction force.

[0016] like Figure 1 As shown, when the locking nut internal thread (3) and the mounting nut external thread (4) are both tapered threads and have different pitches, when the locking nut (2) is tightened on the mounting nut (1), a wedge force is generated, causing the bellows body (6) to contract radially inward; and an axial tensile and compressive force is also generated, causing the bellows body (6) to be partially stretched or compressed axially. At this time, the thread surface of the mounting nut external thread (4) of the bellows body (6) of the mounting nut (1) and the thread surface of the locking nut internal thread (3), the thread surface of the mounting nut internal thread (5) and the bolt external thread surface are more strongly bonded, and the friction force is greater.

[0017] Implementation method: When processing and manufacturing the installation nut (1), the tooth tip of the internal thread (5) of the installation nut and the tooth root of the external thread (4) of the installation nut are radially opposite to each other, and the tooth root of the internal thread (5) of the installation nut and the tooth tip of the external thread (4) of the installation nut are radially opposite to each other, and the internal and external threads form a bellows body (6) similar to the shape of a bellows; when installing the locking nut (2), the locking nut (2) can be heated and expanded first and then tightened on the bellows body (6) of the installation nut (1); after the locking nut (2) cools down, the bellows body (6) of the installation nut (1) is again subjected to radial compression or axial compression, tensile deformation, thereby increasing the extremely strong bonding force.

Claims

1. A bellows type variable pitch self-locking nut comprises a mounting nut (1), a locking nut (2), an inner thread of the locking nut (3), an outer thread of the mounting nut (4), an inner thread of the mounting nut (5), and a bellows body (6). Features: (1) The mounting nut (1) has internal and external double threads, and the external thread (4) of the mounting nut has a straight thread or a tapered thread; (2) The internal thread of the locking nut (3) adopts internal straight thread or internal tapered thread; (3) The inner thread (3) of the locking nut and the outer thread (4) of the mounting nut are installed in coordination; (4) the tooth tip of the internal thread (5) of the mounting nut and the tooth root of the external thread (4) of the mounting nut are radially opposite to each other, the tooth root of the internal thread (5) of the mounting nut and the tooth tip of the external thread (4) of the mounting nut are radially opposite to each other, and the internal and external threads form a bellows body (6) similar to the shape of a bellows; (5) The external thread (4) of the mounting nut may be a non-uniform pitch (variable pitch) thread.

2. According to the bellows-type variable pitch self-locking nut as described in claim 1, when the internal thread (3) of the locking nut and the external thread (4) of the mounting nut are both tapered threads, the pitch of the internal thread (3) of the locking nut is less than or equal to or greater than the pitch of the external thread (4) of the mounting nut; when the internal thread (3) of the locking nut and the external thread (4) of the mounting nut are both straight threads, the pitch of the internal thread (3) of the locking nut is less than or greater than the pitch of the external thread (4) of the mounting nut.

3. According to claim 1 and claim 2, in the bellows type variable pitch self-locking nut, when the internal thread (3) of the locking nut and the external thread (4) of the mounting nut are both straight threads, the pitches of the internal thread (3) of the locking nut and the external thread (4) of the mounting nut are not equal. When the internal thread (3) of the locking nut and the external thread (4) of the mounting nut are tightened together, the internal thread (3) of the locking nut will generate an axial tensile force or a contraction force on the bellows body (6) of the mounting nut (1). The bellows body (6) of the mounting nut (1) will be stretched or compressed in the axial direction. The pitches of the internal and external threads of the bellows body (6) of the mounting nut (1) will change. The thread surfaces of the external thread (4) of the mounting nut and the locking nut internal thread (3), the thread surfaces of the internal thread (5) of the mounting nut and the external thread surfaces of the bolt are enhanced, and the friction force is increased.

4. According to claim 1 and claim 2, the bellows type variable pitch self-locking nut, when the inner thread (3) of the locking nut and the outer thread (4) of the mounting nut are both tapered threads with equal pitches, a wedge force is generated during the process of tightening the locking nut (2) on the mounting nut (1), which will cause the bellows body (6) of the mounting nut (1) to shrink and deform radially inward, and the bonding force between the thread surface of the mounting nut outer thread (4) and the thread surface of the locking nut inner thread (3), the thread surface of the mounting nut inner thread (5) and the outer thread surface of the bolt is enhanced, thereby increasing the friction force.

5. As described in claim 3 and claim 4, in the bellows type variable pitch self-locking nut, when the inner thread (3) of the locking nut and the outer thread (4) of the mounting nut are both tapered threads and the pitches are unequal, when the locking nut (2) is tightened on the mounting nut (1), a wedge force is generated to cause the bellows body (6) to contract radially inward; and an axial tensile or compressive force is also generated to cause part of the bellows body (6) to be stretched or compressed axially. At this time, the thread surface of the mounting nut outer thread (4) and the thread surface of the locking nut inner thread (3), the thread surface of the mounting nut inner thread (5) and the outer thread surface of the bolt have stronger bonding force and greater friction.

6. As described in claim 3 and claim 4, the bellows-type variable pitch self-locking nut, the locking nut (2) of the invention is better locked on the mounting nut (1) after heating.