1. High transmission accuracy and positioning accuracy;

2. Wide feed speed adjustment range;

3. Quick response;

4. Backlashless transmission;

5. Good stability and long service life;

6. Easy to use and maintain. Therefore, the feed motion system of CNC machine tools, especially the contour control feed motion system, must realize the automatic control of feed motion position and movement speed, which requires high positioning accuracy and good dynamic response characteristics.

In the mechanical transmission device of CNC machine tools, the linear feed movement mainly has three directions: transverse, longitudinal and vertical, namely X, Y and Z; The feed axis of CNC lathes is X axis and Z axis, and the CNC milling machine or machining center is X, Y axis and Z axis. Whether it is a CNC lathe or a machining center machine tool, their horizontal feed shaft and vertical feed shaft are basically the same in structure, mainly composed of transmission part and support part. The installation of the vertical feed shaft needs to consider the self-locking of the lead screw to prevent the headstock from sliding due to a sudden power failure, so a brake device must be installed.