Housing Corrosion Leading to Reduced Precision

[Kayley]

Hello everyone, I am using this hollow rotary actuator (https://www.oyostepper.com/category-198-b0-Hollow-Rotary-Actuator.html) on an electroplating line where the environment contains acid mist.

After six months of operation, I noticed that the output rotation had become sluggish and positioning accuracy had deteriorated.

Upon disassembly, I found severe corrosion on the aluminum alloy housing—particularly on the inner wall of the hollow bore and the sealing surfaces. Corrosion products had expanded the bearing preload clearance, and there were signs of acid seepage into the interior.

The original surface treatment was standard anodizing, which could not withstand the acid mist.

I would like to ask for advice on the best materials or surface treatments for actuators in this type of corrosive environment. Should I opt for a stainless steel housing or a Teflon coating? How should the sealing structure be reinforced?

Thank you all in advance for your help and guidance.