Over a four-month period, test measurements were made on a jaw crusher in the Boliden Renström underground mine in northern Sweden. Located at a depth of 840 meters, this heavy-duty machine crushes ore at a normal operating speed of 181 RPM.

This case study describes the condition monitoring setup and findings during the test period. Through the use of a software “crushing filter”, disturbances from the crushing process on the measurements were filtered out. Multiple band values were used to distinguish the bearing frequencies from the strong modulation components.

During the trial period, two small outer race damages were detected. Due to the early stage of the damages, no actions were taken but the online system remains in place and close monitoring of the development of these damages continues.