Evaluation of Lubrication Performance in Ball Screws by the Electrical Impedance Method (EIM)

Abstract

Applying the electrical impedance method (EIM) to ball screws allows for the measurement of oil-film thickness and metal contact ratio along with broad evaluations of lubrication performance inside the actual product, a feat that was difficult until now. We upgraded conventional EIM and improved measurement accuracy. And we evaluated lubrication performance inside actual products with various lubricants and surface properties and expect the improved EIM to be useful in extensive future applications.