BALL SCREW ASSEMBLY

BALL SCREW ASSEMBLY

The ball screw assemblies consist of a threaded bar whose threads act as the raceways for the balls, and of a T-nut with balls inside it. The threads of the bar may be created simply by rolling them – rolled screws – or by machining them followed by grinding – ground screws. The T-nut may be flanged, cylindrical and smooth or cylindrical and threaded. The ball screw may actually be considered as a real and effective transmission, which is able to transform rotary motion into linear traversing motion with minimum friction and maximum geometric precision and repeatability. Operational precision depends on how it is manufactured (explained above), on the class in which the actual screw is supplied, on the pre-load of the T-nut and on the class of the bearings that support it.

The stiffness and carrying capacity on the other hand depend naturally on the size – diameter and pitch – but also on the type of supports used (bearings, their configuration and type and assembly), on the distance between them and on the rotation speed. The screws can be supplied with their ends machined to customer drawing, in other words turned, ground, milled, with slots, bores and threads, so that they are ready for assembly and use, by mounting the supports and connection elements on the drive. The pre-load of the T-nut may be realised and calibrated by selecting the ball-T-nut and T-nut-screw pair.

 

PDF  Ball Screw and Support Units Quick reference Guide        
     

Typology Series available
Nuts SFUR, SFER, SFIR, BSHR, SFSR
Rolled/ground shafts SCR, SSR
Support units EK, FK, BF, BK
Share Facebook
Share