Compression type locknut
By designing a tapered thread structure on the nut and changing the thread contact surface, the friction force is maintained by using compressive force, which solves the problem of nut loosening under vibration environment and achieves a low-cost anti-loosening effect.
Patent Information
- Application Number
- CN202512020500.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-02-10
AI Technical Summary
Existing nuts are prone to loosening under vibration, resulting in loss of fastening effect. Existing anti-loosening nut technology is costly and not practical enough.
A compression-type anti-loosening nut was designed. By machining a tapered thread on the main nut and changing the thread contact surface of the secondary nut from bottom contact to top contact, the frictional force is kept constant by the compressive force between the main nut and the secondary nut, thus preventing loosening.
It effectively prevents nuts from loosening in vibrating environments, maintains a tight fit, and reduces costs.
Smart Images
Figure CN121497719A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of machining and relates to a compression-type anti-loosening nut, which is suitable for various occasions and fields where bolts and nuts are needed to fix items. Background Technology
[0002] Screws, as a standard component, are widely used in many fields such as industry, agriculture, transportation, national defense, mining, aviation, and aerospace. The fastening of bolts and nuts is an important means of securing workpieces. However, due to the working environment, bolts and nuts that are locked under vibration may loosen in reverse, thus losing their fastening effect. Although many anti-loosening nuts have emerged at home and abroad, their practical cost remains high due to technical and processing reasons.
[0003] The main reason for loose nuts during daily life and work is that microscopic elastic deformation occurs in fasteners such as bolts during vibration, which leads to changes in the preload of the nut, a decrease in the friction between the threads, and ultimately, slippage and loosening of the nut.
[0004] By analyzing the loosening principle, the design of the compression anti-loosening nut was obtained. The main principle is that the main nut is pre-tightened normally, and the auxiliary nut changes the tooth surface contact surface of the auxiliary nut's internal thread through the tapered thread, so that a compressive force is generated between the main nut and the auxiliary nut. No matter how much vibration occurs, the friction of the main nut can be kept unchanged, thus achieving the purpose of loosening. Summary of the Invention
[0005] Compression locknut.
[0006] The technical solution of this invention is as follows: a compression-type anti-loosening nut includes a main nut and a secondary nut; the main nut is used for normal tightening engagement with the bolt, and a tapered thread is machined on the outer surface in the screw-out direction; the secondary nut is a retaining nut, and a tapered hole thread is machined on the screw-in end of the nut to cooperate with the tapered thread of the main nut. The helix of the tapered thread is offset forward relative to the helix of the straight internal thread on the main nut, so that the contact surface between the straight internal thread on the secondary nut and the external thread on the bolt changes from the original lower contact surface to the upper contact surface during tightening. This allows the main nut and the secondary nut to apply a compressive force to the bolt, and the bolt to apply an expansion force relative to the main nut and the secondary nut, thereby ensuring the friction of the straight internal thread of the main nut under vibration, thus achieving anti-loosening. Attached Figure Description
[0007] Figure 1 A three-dimensional view of the compression lock nut.
[0008] Figure 2 3D view of the main nut.
[0009] Figure 3 3D view of the secondary nut.
[0010] In the diagram, there is a main nut (1), secondary nuts (2), main nut 1-1 with a straight internal thread, main nut 1-2 with a tapered thread, secondary nut 2-1 with a straight internal thread, and secondary nut 2-2 with a tapered hole thread. Detailed Implementation
[0011] The invention will now be further described with reference to the accompanying drawings.
[0012] Figure 2 The diagram shows a three-dimensional view of the main nut, which is the main nut 1. A straight internal thread is located in the middle of the main nut 1, and this internal thread has the same thread size as the mating bolt thread. A face with a thread, namely the main nut tapered thread 1-2, is located on the surface of the main nut 1. The vertical pitch of the main nut tapered thread 1-2 is equal to the pitch of the main nut straight internal thread 1-1. The helix of the main nut tapered thread 1-2 is offset forward relative to the helix of the main nut straight internal thread 1-1 by a distance of 10-20% of the pitch of the main nut straight internal thread 1-1. The taper of the main nut tapered thread 1-2 is 5 degrees or 6-7 degrees.
[0013] Figure 3 The diagram shows a three-dimensional view of the auxiliary nut, which is 2 in total. A straight internal thread 2-1 is located in the middle of the auxiliary nut 2. This internal thread has the same thread size as the mating bolt thread. A tapered thread 2-2 is located at the screw-in end of the auxiliary nut 2. The vertical pitch of the tapered thread 2-2 is equal to the pitch of the straight internal thread 2-1. The helix of the tapered thread 2-2 is positioned relative to the helix of the straight internal thread 2-1. The taper of the tapered thread 2-2 is 5 degrees or 6-7 degrees. The dimensions of the tapered thread 2-2 are the same as those of the main nut tapered thread 1-2.
[0014] Figure 1 The diagram shows a three-dimensional representation of a compression lock nut, which includes a main nut 1 and a secondary nut 2. In use, the main nut 1 is screwed in first, with the tapered thread 1-2 of the main nut facing the direction of the mating bolt. The main nut 1 is tightened normally until the preload value is reached. Then, the secondary nut 2 is screwed in until the tapered threads are fully engaged, reaching the preload value. Due to the offset of the helix of the tapered thread 1-2 of the main nut relative to the helix of the straight internal thread 1-1 of the main nut, the contact surface between the thread of the straight internal thread 2-1 of the secondary nut and the mating bolt changes from the lower contact surface to the upper contact surface. This generates a compressive force under the tapered thread connection of the main nut 1 and the secondary nut 2. In a vibrating environment, this force can maintain the thread friction of the main nut, and the expansion force generated by the bolt also strongly inhibits slippage of the main nut.
[0015] This article uses specific examples to illustrate the inventive concept in detail. The description of the above embodiments is only to help understand the core idea of the present invention. It should be noted that any obvious modifications, equivalent substitutions or other improvements made by those skilled in the art without departing from the inventive concept should be included within the protection scope of the present invention.
Claims
1. A compression-type anti-loosening nut, characterized in that... The compression lock nut includes a main nut 1 and a secondary nut 2; after the main nut 1 is tightened, the secondary nut 2 is screwed in; the tapered thread 1-2 of the main nut is located in the screw-out direction of the bolt, and the tapered hole thread 2-2 of the secondary nut is located in the screw-in direction of the bolt. The bolt is a fastener that needs to cooperate with the compression lock nut, and can be a standard bolt or a custom bolt.
2. The compression-type anti-loosening nut according to claim 1, characterized in that... The taper of the main nut tapered thread 1-2 is between 5 degrees and 6-7 degrees, and the taper of the auxiliary nut tapered hole thread 2-2 is the same as that of the main nut tapered thread 1-2.
3. The compression-type anti-loosening nut according to claim 1, characterized in that... The vertical pitch of the tapered thread 1-2 of the main nut and the tapered hole thread 2-2 of the auxiliary nut is equal to the pitch of the straight internal thread 1-1 of the main nut.
4. The compression-type anti-loosening nut according to claim 1, characterized in that... The helix of the main nut tapered thread 1-2 is offset in the direction of screwing relative to the helix of the main nut straight internal thread 1-1, with an offset amount of 10-20% of the pitch of the main nut straight internal thread 1-1, and the helix of the secondary nut tapered hole thread 2-2 coincides with the helix of the secondary nut straight internal thread 2-1; or the helix of the secondary nut tapered hole thread 2-2 is offset in the direction of screwing relative to the helix of the secondary nut straight internal thread, with an offset amount of 10-20% of the pitch of the main nut straight internal thread 1-1, and the helix of the main nut tapered hole thread 1-2 coincides with the helix of the main nut straight internal thread 1-1.