The transmission type, based on the relative movement combination of the screw and nut, consists of two basic types of fundamental transmission for screw jacks.

(1)Nut fixation, screw rotation and movement; this transmission type, due to the nut's inherent supporting function, eliminates the additional axial movement that could be caused by screw shaft bearings. It features a simpler structure and achieves higher transmission accuracy. However, its axial size should not be too long, as it would compromise rigidity. Therefore, it is only suitable for applications with short travel distances.

(2)Nut rotation needs to be restricted in this transmission system, so a guiding device is required. Its features include a compact structure, good screw thread rigidity, and is suitable for applications with long working travel.