Ball Screws: Maximum precision and long service life
A Ball Screw is a “Screw-Nut” type of drive that converts the rotational motion of a stepper motor or servo drive’s shaft to a screw into a translational motion box of a nut mounted on/in a table or spindle. Originally intended for use in high-precision equipment, it is in fact the basis for constructing controlled axis motion diagrams in 90% of today’s CNC machines, regardless of precision requirements.

Advantages of ball screws over other types of gears:
High accuracy in linear motion;
Efficiency of 98%;
Long service life;
In Ball Screws, unlike gear ratios, the preload is created according to the desired grade;
Since Ball Screws do not require additional force to move the table or spindle housing from rest to motion, lower power motors can be used.
Disadvantages: they are afraid of dirt and dust, their length is limited (due to the danger of sagging screws, which can lead to deformation of the tightening point and accelerate the wear of the nut), and they have an increased sensitivity to vibration.

Classification of Ball Screws
Ball screws are categorized according to several criteria.

Screw manufacturing technology. On rolled screws, the recesses are formed by cold rolling. This method is cheaper, but is only suitable for medium accuracy grades. For ground screws, the recesses are cut out and then ground prior to heat treatment. It proves to be more expensive, but more accurate.

Nut type. There are flanged and round types, each of which is subdivided into single and double types.

Types of ball return mechanisms. External Recirculation – The ball is returned to the work area through a tube located outside the nut body. The return cycle is 1.5 to 5.5 revolutions of the screw. Internal Recirculation – The ball transition cuts into the internal contour of the nut with each revolution. The return cycle is one revolution. End Return System – The ball travels along the complete path of all turns located inside the nut. For gears with large pitch propellers.

Propeller pitch is the basic criterion for selecting gears to solve a particular problem. Fine pitch ballscrews are used in low speed machines and are characterized by long service life and high load capacity. Increasing the number of steps results in a reduced ability to absorb high loads, but increases the speed of movement.