On the one hand, it is caused by friction during the long use of the screw lifter, that is, there will be a little friction between the worm and the screw every time they rotate, and the friction also generates a lot of heat. If it is at a high frequency and high utilization rate, the heat in this part is very large, Therefore, the heat in this part will cause a slight increase in the bearing position and oil seal in the housing. This, in turn, will cause the micro displacement of the worm and the worm gear, causing instability, so it will also promote the generation of large friction. A cycle starts again, so on the other hand, it is caused by the friction between the worm and the worm gear, worm gear and the screw, Moreover, they are in direct contact with each other. When the worm and the worm gear rotate at a high speed, the worm and the worm gear will generate a lot of friction. The friction between the worm gear and the screw will be greater, and they will squeeze each other. In this case, a large number of grinding materials will be generated. Under the effect of friction, these grinding materials will generate a large number of powdery objects. In this case, it is to promote the worm and the worm gear, The friction between the worm gear and the lead screw will cause the gap of the elevator to increase over time, resulting in swing and increased noise.