WeChat: 13679287344
Phone: +86 13679287344
E-mail: [email protected]
Add: Room1102, Land Center T1, Yanzhan Road, No. 1111, Qujiang New District, Xi'an, China.
Phone: +86 13679287344
E-mail: [email protected]
Add: Room1102, Land Center T1, Yanzhan Road, No. 1111, Qujiang New District, Xi'an, China.
The methods of bolts anti-loosening
Time: 2024-12-06 Source: Author:
There are various methods of bolt loosening prevention, each of which has its own specific application scenarios and advantages and disadvantages. Anti-loosening measures can be categorized according to the principle of action: friction anti-loosening, mechanical anti-loosening and permanent anti-loosening. Mechanical anti-loosening and friction anti-loosening are called detachable anti-loosening, while permanent relaxation is called non-detachable anti-loosening. This article introduces in detail the different methods of bolts anti-loosening.
Friction anti-loosening
Double nuts against tightening anti-loosening: Tighten two nuts on the screw rod continuously. There will always be pressure between the contact surfaces of the nuts, the screw-engaged part in the nut is pulled, and the nut is compressed. This set of closed forces will then form a friction force that is not affected by changes in external loads. The structure is simple and easy to use, but the structure size is large, which is suitable for smooth, low-speed, heavy-duty fixtures on the connection to prevent loosening.
Spring washers to prevent loosening: add spring washers between the nut and the original nut mating plane. Spring washers due to the tightening of the nut flattened by the elastic force generated by the threaded vice to maintain a certain pressure between the anti-loosening. The tip of the beveled cut of the washer should be against the direction of nut loosening to stop the nut from reversing, but it is easy to damage the plane of contact with the spring washer (nut and connecting parts) for general connection.
Self-locking nuts: Self-locking nuts are generally self-locking by friction, preventing the nut and bolt from rotating relative to each other, thereby preventing loosening. Among them, the 30° wedge thread anti-loosening technology is a special kind of self-locking nut, which increases the locking force by changing the angle of the thread, thus improving the anti-loosening effect. The price of self-locking nuts is relatively high, but the anti-loosening performance is stable.
Mechanical anti-loosening
Stop gasket: A stop gasket is a gasket used to prevent nuts or other fasteners from loosening. It is usually made of a metal sheet with a serrated or toothed shape that can be inserted between the nut and the thread, increasing friction and preventing the nut from loosening. Stop gaskets are widely used in a variety of machinery and equipment, especially in the need to withstand vibration or shock.
Cotter pin: prevent loosening by fixing the screws, but the pin may break during mechanical movement, resulting in screw and nut wear and anti-loosening performance is unstable.
Tandem steel wire: tandem steel wire to prevent loosening is a way to prevent multiple bolts or other fasteners from loosening by stringing them together with mild steel wire. This method mainly uses the expansion and elasticity of steel wire to absorb external forces and maintain the stability of fasteners. Tandem wire loosening method is simple, reliable and effective, but the disassembly is more troublesome, suitable for aircraft, rockets and other occasions that require high reliability.
Permanent anti-loosening
Spot welding: The bolts and nuts are fixed together by spot welding to achieve permanent anti-loosening. This method is suitable for some occasions that do not require frequent disassembly.
Riveting: the use of rivets will be riveted to the bolt and nut, can also be realized permanently anti-loosening. However, the riveted connection can not be disassembled, so it is suitable for some occasions that do not need to be disassembled.
Bonding: The use of adhesives to glue bolts and nuts together can also achieve the effect of anti-loosening. However, the selection and use of adhesives need to be careful to ensure the reliability and durability of the connection.
In summary, there are various methods to prevent bolts from loosening, and the choice of which method depends on the specific application scenarios and requirements. In practical applications, one or more anti-loosening methods can be selected and used in combination as needed to improve the reliability and durability of the connection.
Friction anti-loosening
Double nuts against tightening anti-loosening: Tighten two nuts on the screw rod continuously. There will always be pressure between the contact surfaces of the nuts, the screw-engaged part in the nut is pulled, and the nut is compressed. This set of closed forces will then form a friction force that is not affected by changes in external loads. The structure is simple and easy to use, but the structure size is large, which is suitable for smooth, low-speed, heavy-duty fixtures on the connection to prevent loosening.
Spring washers to prevent loosening: add spring washers between the nut and the original nut mating plane. Spring washers due to the tightening of the nut flattened by the elastic force generated by the threaded vice to maintain a certain pressure between the anti-loosening. The tip of the beveled cut of the washer should be against the direction of nut loosening to stop the nut from reversing, but it is easy to damage the plane of contact with the spring washer (nut and connecting parts) for general connection.
Self-locking nuts: Self-locking nuts are generally self-locking by friction, preventing the nut and bolt from rotating relative to each other, thereby preventing loosening. Among them, the 30° wedge thread anti-loosening technology is a special kind of self-locking nut, which increases the locking force by changing the angle of the thread, thus improving the anti-loosening effect. The price of self-locking nuts is relatively high, but the anti-loosening performance is stable.
Mechanical anti-loosening
Stop gasket: A stop gasket is a gasket used to prevent nuts or other fasteners from loosening. It is usually made of a metal sheet with a serrated or toothed shape that can be inserted between the nut and the thread, increasing friction and preventing the nut from loosening. Stop gaskets are widely used in a variety of machinery and equipment, especially in the need to withstand vibration or shock.
Cotter pin: prevent loosening by fixing the screws, but the pin may break during mechanical movement, resulting in screw and nut wear and anti-loosening performance is unstable.
Tandem steel wire: tandem steel wire to prevent loosening is a way to prevent multiple bolts or other fasteners from loosening by stringing them together with mild steel wire. This method mainly uses the expansion and elasticity of steel wire to absorb external forces and maintain the stability of fasteners. Tandem wire loosening method is simple, reliable and effective, but the disassembly is more troublesome, suitable for aircraft, rockets and other occasions that require high reliability.
Permanent anti-loosening
Spot welding: The bolts and nuts are fixed together by spot welding to achieve permanent anti-loosening. This method is suitable for some occasions that do not require frequent disassembly.
Riveting: the use of rivets will be riveted to the bolt and nut, can also be realized permanently anti-loosening. However, the riveted connection can not be disassembled, so it is suitable for some occasions that do not need to be disassembled.
Bonding: The use of adhesives to glue bolts and nuts together can also achieve the effect of anti-loosening. However, the selection and use of adhesives need to be careful to ensure the reliability and durability of the connection.
In summary, there are various methods to prevent bolts from loosening, and the choice of which method depends on the specific application scenarios and requirements. In practical applications, one or more anti-loosening methods can be selected and used in combination as needed to improve the reliability and durability of the connection.
