What Are The Methods For Preventing Nuts From Loosening? Common Methods For Preventing Loosening Of Fasteners

 Fasteners are an indispensable part of mechanical connections and an important aspect of ensuring stable and safe machine operation. However, during the operation of the machine, fasteners often become loose or even loose due to factors such as vibration, impact, and deformation, causing the machine to lose its original stability and posing danger to the machine. In order to solve this problem, people have developed various methods to prevent loosening of fasteners.

1、 What are the methods for preventing nuts from loosening

1. Flat washer

A washer is a flat metal ring used to protect the surface of the connected part from being scratched by the nut, disperse the pressure of the nut on the connected part, and prevent loosening.

2. Flat washer and spring washer

Spring washers are widely used in load-bearing and non load-bearing structures of general mechanical products, characterized by low cost, convenient installation, and suitable for frequently installed and disassembled parts. But the anti loosening ability of spring washers is very low!

3. Self-locking nut

The main functions of self-locking nuts are anti loosening and anti vibration. For special occasions. Its working principle is generally self-locking by friction. The types classified by function include nylon ring embedded, necked closure, and metal anti loosening device. They all belong to the effective torque type locking nuts.

4. Nut locking liquid

Applying nut locking solution to the bolt tightening area and then tightening the nut can achieve the effect of locking.

5. Double nut (left and right rotation) anti loosening

It is also a good method to tighten and prevent loosening by combining a left-hand nut with a right-hand nut.

6. Screw and nut drilling and pin fixation

In machinery, pins are mainly used for assembly positioning and can also be used as overload shear connections in connection and relaxation level safety devices. The locking effect is good, but it will damage the thread.

2、 Common methods for preventing loosening of fasteners

There are three commonly used anti loosening methods: friction anti loosening, mechanical anti loosening, and permanent anti loosening. Mechanical anti loosening and friction anti loosening are called detachable anti loosening, while permanent anti loosening is called non detachable anti loosening.

Commonly used permanent anti loosening methods include spot welding, riveting, bonding, etc. Cannot be reused. Common friction anti loosening methods include using gaskets, self-locking nuts, and double nuts. Common mechanical anti loosening methods include using split pins, stop washers, and string wire ropes. Mechanical anti loosening methods are relatively reliable, and for important connections, mechanical anti loosening methods should be used.

1. Friction anti loosening

(1) Spring washer anti loosening

After the assembly of the spring washer, the washer is flattened, and its rebound force can maintain the compression force and friction force between the threads, thereby achieving anti loosening.

(2) Counter nut anti loosening

Use the nut to exert additional tension and friction force on the bolt type. Due to the use of an extra nut and its unreliable operation, it is currently being used less frequently.

(3) Self locking nut anti loosening

Utilize the elastic force of the closure to tightly compress the threads, ensuring reliable anti loosening.

(4) Elastic ring nut anti loosening

Insert fibers or nylon into the thread to increase friction. The elastic ring also plays a role in preventing liquid leakage.

2. Mechanical anti loosening

(1) Slotted nut and split pin anti loosening

Use a split pin to pass through the small hole at the end of the bolt and the groove of the nut, or drill the pin hole to form a fixation.

(2) Round nut and stop washer

After tightening the nut, fold one of the outer tongues of the washer into one of the grooves of the nut.

(3) Stop washer

If two bolts need to be double interlocked tightly, double stop washers can be used.

(4) Tandem steel wire anti loosening

Connect the screws in series and brake each other. It is necessary to pay attention to the direction in which the steel wire penetrates.

3. Permanent anti loosening

(1) Edge punching method for preventing loosening

After tightening the nut, punch the end of the thread to damage the thread.

(2) Adhesive anti loosening

Insert thread adhesive and apply it to the thread fitting surface, ensuring good anti loosening effect.

In summary, there are many methods for preventing loosening of fasteners, and different methods can be adopted according to different machines and usage conditions. Mechanical anti loosening and friction anti loosening are commonly used detachable anti loosening methods, while permanent anti loosening is suitable for fasteners that need to be permanently fixed on some machines or equipment. Choosing appropriate anti loosening methods plays an important role in ensuring the stable operation of the machine.