Five common types of self-locking nuts
June 08,2022
Flat Head Allen Socket Sleeve Square Internal And External Thread Nut
The functions of self-locking nuts are mainly to prevent loosening and anti-vibration. For special occasions. Its working principle is generally self-locking by friction. The types of self-locking nuts classified by function include those with nylon rings, those with neck closures, and those with metal anti-loosening devices. They are all effective torque locknuts
What is a self-locking nut
Self-locking Square Thread Nut is a new type of high anti-vibration and anti-loosening fastening parts, which can be used in various mechanical and electrical products with a temperature of -50 to 100 ℃. Aerospace, aviation, tanks, mining machinery, automobile transportation machinery, agricultural machinery, textile machinery, electrical products and various types of machinery have a sharp increase in the demand for nylon self-locking nuts, because its anti-vibration and anti-loosening performance is much higher than other Various anti-loose devices, and the vibration life is several times or even dozens of times higher.
Working principle of self-locking nut
The self-locking Square Thread Nut generally relies on friction. The principle is to press the embossed teeth into the preset holes of the sheet metal. Generally, the diameter of the square preset holes is slightly smaller than that of the rivet nut. The nut is connected with the locking mechanism. When the Square Thread Nut is tightened, the locking mechanism locks the ruler body, and the ruler frame cannot move freely to achieve the purpose of locking; when the nut is loosened, the locking mechanism disengages the ruler body, and the ruler The frame moves along the ruler.
The self-locking nut standard GJB125.1~125.6-86 stipulates that the double-ear sealing swimming self-locking nut is composed of four parts: sealing cover, self-locking nut, pressure ring and sealing ring. It has compact structure and reliable sealing, and is suitable for products whose working pressure is not more than 2atm, working medium is gasoline, kerosene, water or air, and the operating temperature is -50～100℃. However, it has certain difficulties in the manufacturing process and air tightness test.
Types of self-locking nuts
1. High-strength self-locking Internal And External Thread Nut is a classification of self-locking nuts, with high strength and reliability. It is mainly based on the introduction of European technology, which is used for road construction machinery, mining machinery, vibration machinery and equipment, etc. At present, there are very few domestic manufacturers of such products.
2. Nylon self-locking Flat Head Allen Socket Sleeve Nut nylon self-locking nut is a new type of high-vibration and anti-loosening fastening parts, which can be used in various mechanical and electrical products at temperatures of -50 to 100 °C.
At present, the demand for nylon self-locking nuts in aerospace, aviation, tanks, mining machinery, automobile transportation machinery, agricultural machinery, textile machinery, electrical products and various types of machinery has increased sharply, because its anti-vibration and anti-loosening performance is greatly improved. Compared with other various anti-loosening devices, the vibration life is several times or even dozens of times higher.
At present, more
than 80% of accidents in machinery and equipment are caused by loose fasteners, especially in mining machinery, and the use of nylon self-locking Flat Head Allen Socket Sleeve Nut can prevent fasteners from loosening. of major accidents.
3. Swimming self-locking Internal And External Thread Nut GJB125.1～125.6-86 The double-ear sealing swimming self-locking nut is composed of four parts: sealing cover, self-locking nut, pressure ring and sealing ring. It is compact in structure and reliable in sealing. It is suitable for products whose working pressure is not more than 2atm, the working medium is gasoline, kerosene, water or air, and the operating temperature is -50 ~ 100 ℃. However, it has certain difficulties in the manufacturing process and air tightness test.
4. Spring self-locking nut The spring clip self-locking nut consists of an S-shaped spring clip and a self-locking nut. The S-shaped spring clip is provided with a clamping hole for clamping the self-locking nut and a transition hole for passing through the bolt. And the guide hole for bolt guidance, the self-locking nut is placed between the clamping hole and the transition hole, and clamped in the clamping hole.
5. Shibi solid self-locking nut Shibi solid self-locking nut. There is a 30-degree wedge-shaped slope at the bottom of the female thread. When the bolt and nut are tightened against each other, the cusp of the bolt is tightly pressed against the wedge-shaped slope of the Spicer thread, thus generating a large locking force. .
Due to the change in the angle of the tooth profile, the normal force applied to the thread-to-thread contact is at a 60-degree angle to the bolt axis, rather than the 30-degree angle of ordinary threads. Obviously, the normal pressure of the thread is much larger than the tightening pressure, so the anti-loosening friction force generated is bound to be greatly increased.
At the same time, when the crest of the male thread is engaged with the female thread of the Spire, the tooth tip at the crest is easily deformed, so that the load is evenly distributed over the entire length of the contacting helix, avoiding more than 80% of the occlusion of ordinary standard threads. The phenomenon in which the total load is concentrated on the thread surfaces of the first and second teeth.
Therefore, Square Thread Nut, Flat Head Allen Socket Sleeve Nut, and Internal And External Thread Nut not only overcome the shortcomings of ordinary standard coupling pairs that are easy to loosen themselves under vibration conditions, but also extend the service life.