How to protect ball screws in harsh environments？

The harsh environment can cause serious damage to the motion system components,especially the linear guide and ball screw rolling system.There are measures that can help prevent these environmental conditions from severely shortening the life of ball screw assemblies.

●Materials suitable for harsh environments

When selecting ball screws for applications that involve liquid contamination,such as water,acid or alkaline cleaning solutions,the first consideration is the material of the components,especially the screw shafts,ballnuts and seals.

While screw shafts and ballnuts are typically made of steel to achieve high load capacity and rigidity,there are other material options that can help them withstand challenging environments.For example,protective coatings such as electroless nickel plating or black oxide can be applied to screw shafts and,in some cases,ballnut housings.Some manufacturers offer stainless steel ball screw shafts for use in applications where water or chemicals pose significant challenges.

●Seals protect against solid and liquid contaminants

Seals are located at each end of the ballnut to prevent the spread of contaminants in liquid and solid form between the load-bearing ball and the raceway.In addition to preventing contamination,these seals also have the important function of maintaining lubrication.

Almost all seals provide some level of protection against solid contamination,such as metal or wood shavings,and ceramic or glass dust.Standard ballnut seals are usually made of FKM,but manufacturers offer other materials,such as EPDM,that can withstand extreme temperatures and protect against specific chemicals.

●Reduce the effects of temperature

The normal operating temperature of the ball screw assembly depends in part on the type of seal and lubricant used,but is usually between 0°C and 80°C.Temperatures above or below these limits and significant temperature fluctuations can lead to thermal expansion of the screw shaft.

One way to mitigate the effects of thermal expansion is to mount the screw shaft under tension,with fixed bearings at both ends.This helps prevent the screw from expanding(or contracting)due to heat(or cold).Forced air cooling of screw assemblies is also a good solution in some applications.A more extreme measure-but usually used in applications such as machine tools where motion accuracy is absolutely critical - is to use a hollow screw shaft with an internal cooling function to reduce the temperature of the screw material.

The ball screw is installed under tension and has fixed bearings at both ends to help reduce thermal expansion.

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