As the name suggests, a locknut is a kind of nut to pre […]
As the name suggests, a locknut is a kind of nut to prevent loosening, and is generally used for preventing loosening of machinery and equipment. Let's introduce its advantages and anti-loose methods.
A locknut is a nut, a part that is screwed together with a bolt or screw for fastening. All production machinery must use an original part. The locknut is a part that tightly connects the mechanical equipment. Threads, lock nuts and screws of the same specification can be connected together. The following describes in detail 4 ways to prevent loosening of lock nuts.
The lock nut stopper directly restricts the relative rotation of the lock nut pair. Such as the use of open gear pins, tandem steel wires and stop washers. Since the lock nut stopper has no pre-tightening force, the anti-loosening stopper can only be effective when the lock nut is loosened to the stop position. Therefore, the lock nut is not prevented from loosening in practice but avoids falling out.
Riveting and anti-loosening
After tightening, using punching, welding, bonding and other methods, the lock nut pair loses the movement characteristics and the connection becomes an undetachable connection. The disadvantage of this method is that the bolt can only be used once, and the disassembly is very difficult, and the bolt pair must be destroyed before disassembly.
This is the most widely used anti-loosening method. This method generates a positive pressure between the lock nut pairs that does not change with the external force to generate a friction force that can prevent the lock nut pairs from rotating relative to each other. This positive pressure can be achieved by compressing the lock nut pair axially or in both directions at the same time. For example, elastic washers, double nuts, self-locking nuts and insert locking nuts are used.
It is the double body structure of the lock nut, that is, the anti-loosening method of the Down lock nut.
Flushing method to prevent loosening
After the nut is tightened, punch the thread at the end of the thread to break the thread; the anti-loosening is usually applied to the threaded surface with an anaerobic adhesive. After the nut is tightened, the adhesive can solidify by itself, and the anti-loosing effect is good. The disadvantage of this method is that the bolt can only be used once, and it is very difficult to disassemble, and the bolt pair must be destroyed before it can be disassembled.
Three advantages of locknuts:
First, superior vibration resistance: When the thread is tightened, the crest thread of the bolt is tightly entered into the 30° wedge-shaped slope of the nut to be clamped, and the normal force exerted on the wedge-shaped slope is consistent with the bolt’s The axis is at an angle of 60° instead of 30°. Therefore, the normal force generated when the lock nut is tightened is much greater than that of the ordinary standard nut, which has great anti-loose and anti-vibration ability.
Second, strong wear resistance and shear resistance: the 30° inclined surface of the nut thread bottom can make the nut locking force evenly distributed on all the threads of each tooth. Since the compression force on the thread surface of each tooth is evenly distributed, so Nuts can better solve the problems of thread wear and shear deformation.
Third, good reusable performance: Extensive use shows that after repeated tightening and disassembly of the locknut, its locking force is still not reduced, and the original locking effect can be maintained.