SCREW DRIVES GT, MICRONLine®, KOKON® SCREW ... - BIBUS

Ball Screw Drives KGTScrew DrivesSizing and selectionCritical speed of ball screwsWith thin, fast-rotating screws, there is a danger of “whipping”.The method described below allows the resonant frequency to beestimated assuming a sufficiently rigid assembly. Furthermore, speeds inthe vicinity of the critical speed considerably increase the risk of lateralbuckling. The critical speed is therefore included in the calculation of thecritical buckling force.Maximum permissible speedn zul Maximum permissible speed [rpm]n kr Theoretical critical speed [rpm], that can lead to resonance effects(V) n zul = 0.8 . ➔ see tablen .kr fkrf kr Correction factor, considering the bearing support of the screw. ➔ see table! The operating speed must not exceed 80 % of the maximum speedBearing supportTypical values of correction factor f kr corresponding to the usual cases of installation for standardTheoretical critical speed n kr screw bearings.Theoretical critical speed n kr[rpm]f kr = 0.36f kr = 1.47Case 1 Case 2f kr = 1Case 3 Case 4f kr = 2.23Unsupported length L28 Tel : +49 (0) 7157-124- 0 Web site : www.DanaherMotion.net