Axial clearance usually refers to the maximum axial movement between the screw and the nut when the screw and the nut are not rotating relative to each other. In addition to the clearance of the structure itself, after the axial load is applied, the axial clearance also includes the play caused by elastic deformation.https://cnctraining.cn/
The following conditions should be considered when eliminating the clearance of the ball screw pair through the preload method: the preload can effectively reduce the axial displacement caused by the elastic deformation, but the excessive preload will increase the friction resistance and reduce the transmission efficiency. https://glovepuppetry.com/And shorten the life span. Therefore, it usually takes several adjustments to ensure that the machine tool can operate flexibly under the maximum axial load, which eliminates the gap. Except for a few single-nut structures that use micro-interference balls to eliminate gaps, double-nut structures are commonly used to eliminate gaps.
Double nut tooth difference adjustable backlash structure. Cylindrical external gears are made on the flanges of the two nuts, and the number of teeth difference is
1. The number of teeth of the two internal ring gears is the same as that of the external gear, and they are fixed on with screws and pins. https://berylliumcopper.cn/At both ends of the nut seat, first take out the inner gear ring when adjusting.
According to the size of the gap, make the two nuts turn one tooth or several teeth in the same direction respectively, so that the nuts move closer to each other or move the corresponding distance in the axial direction. , The amount of clearance snacks can be calculated with the following simple formula: In the formula, n is the number of teeth turned by the two nuts in the same direction, t is the lead of the ball screw, and the number of teeth of the gear. Let’s talk about the structure of the gap adjustment type. It is more complicated,https://cncbending.cn/ but it is easy to adjust, and the precise adjustment can be obtained through simple calculation. It is a widely used structure at present. Figure 3.25 is a double nut washer adjustable gap structure. The structure of the nut itself is the same as that of a single nut. , He adjusts the axial gap by the thickness of the Mold repair gasket
3. This adjustment method has the advantages of simple structure, good rigidity and convenient disassembly and assembly, but it is difficult for him to complete the adjustment during mold repair again, and the adjustment accuracy is not as good as Tooth gap adjustment is good.
Double nut threaded clearance adjustment structure, it uses flat keys to limit the rotation of the nut in the nut seat. When adjusting. When adjusting, it is necessary to twist the round nut 3 to move the ball nut 2 a certain distance in the axial direction, and then lock it after eliminating the gap. This adjustment method has the advantages of simple structure and convenient adjustment, but the adjustment accuracy is poor.