Investigation of the contact stiffness variation of linear rolling guides due to the effects of friction and wear during operation

•Contact stiffness variation due to friction and wear is quantitatively explained.•The stiffness model considers the thermal deformation and wear of linear guides.•Stiffness decay is greatly affected by gradually generated wear of the carriage.•The stiffness variation was successfully diagnosed by vibration signals.

This study investigates the contact stiffness variation of linear rolling guides due to the effects of friction and wear during operation. The initial and final contact stiffness models were established. As a validation of the predicted varying stiffness, the experimental modal analysis was performed on a specialized linear guide system. The results show that the contact stiffness of linear guides decrease with the increase of running distance, and the entire stiffness decay could be divided into two distinct stages depending on how the thermal and wear effects influence the contact deformations of the balls at different running distances.