The anti-loosening effect of the lock nut mainly depend […]
The anti-loosening effect of the lock nut mainly depends on the interaction force between the nut and the bolt thread. At present, there are many ways to improve the interaction force between meshing threads, such as the improvement of the thread structure of the Spiro nut, the nylon roughening of the nylon nut, and the surface treatment of the thread.
The first is to use two identical nuts to screw on the same bolt, and add a tightening torque between the two nuts to make the bolt connection reliable.
The second is a special lock nut, which needs to be used together with a lock washer. The special lock nut is not a hexagonal nut, but a middle round nut. There are 3, 4, 6 or 8 gaps on the circumference of the nut (depending on the size of the nut and the product series of the manufacturer). Several notches are not only the focus of the tightening tool, but also the entry point of the locking washer.
The third type is to drill through threaded holes from the outer surface of the nut to the inner thread surface (usually two, distributed at 90 on the outer surface), used to screw in small diameter countersunk screws, the purpose is to thread Apply a centripetal force to prevent the lock nut from loosening. At present, the lock nuts of better quality on the market are inlaid on the inner surface of the nut with copper small pieces that are consistent with the thread of the lock nut, which is used to prevent the radial jacking screw from directly contacting the locked thread and causing damage. By. This kind of lock nut has gradually begun to be applied in the occasion of the shaft end locking of rotating parts, such as the anti-loosening of the bearing at the mounting end of the ball screw.
The fourth type of lock nut is composed of two parts, each part has a staggered cam, because the internal wedge design slope angle is greater than the bolt nut angle, this combination will be tightly bitten into a whole, when vibration occurs At this time, the raised parts of the locknut are staggered to each other to generate lifting tension, so as to achieve a perfect anti-loose effect.
The fifth type is structural anti-loosening. By designing and improving the thread structure, it does not rely on other external factors to obtain its own locking function. Therefore, its applicability is wider than the above-mentioned methods, and the requirements for the environment are also relatively more low.