In all kinds of mechanical connectors, the anti-loosening of bolts is a very important link. There are many ways to prevent bolt loosening, including the use of spring washers to prevent loosening. Spring washer in the screw industry, often called spring gasket. So why it will be frequently used, this is from the role of the spring washer and the principle of open.

1. the role of the spring washer:

The basic function of the spring washer is to apply a force to the nut after it is tightened, increasing the friction between the nut and the bolt! That is, in order to prevent the vibration of the equipment in operation caused by the loosening of the fastening bolts, and increase a protective measure.

2. the anti-loosening principle of spring washer:

The anti-loosening principle of the spring washer is that after the spring washer is pressed flat, the spring washer will produce a continuous elastic force, so that the thread connection pair of the nut and bolt continues to maintain a friction force, producing a resistance moment, so as to prevent the nut from loosening. At the same time, the sharp corner of the spring washer opening is inserted into the surface of the bolt and the connected piece respectively, so as to prevent the bolt from turning relative to the connected piece.

However, in practice, the spring washer only provides 10 N/m of spring force, which is negligible for 280 N/m bolt pretightening torque. Second, such a small force is not enough to make the sharp corner of the spring gasket cut into the bolt and connector surface. After folding observation, the surface of the bolt and the connecting piece have no obvious embedding mark. Therefore, the anti-loosening effect of spring washers on bolts can be ignored.

From the role and principle of the spring washer, the spring washer is not a good way to prevent loosening, or to find an ideal way to increase the friction resistance moment.