As part of its AIP+ (Added Value Programme), NSK’s Condition Monitoring Service (CMS) is a method to determine the health of machine components such as bearings while the machine remains operating. Indeed, data from the process can also be used to help determine (or at least narrow down) the causes of form errors when producing parts on grinding machines.

NSK has used CMS at a factory of its own in the UK. In this case, form errors were occurring on a grinding machine producing bearing raceways. After several repair attempts and a fruitless search for possible faults, it was suspected that the bearings must have a defect. Looking to find a definitive resolution, NSK decided to have a status analysis carried out via the CMS.

Analysis showed that neither the spindle nor work-head dresser were the cause of the form errors. In total, three working days were saved which would have been needed to strip down the spindle and investigate the potential bearing defects, not to mention the associated loss of production time for each of the impacted manufacturing cells. As a result, savings in maintenance time and downtime were calculated at €13,080.

In a second example, a user of a centerless grinding machine detected that form errors were occurring in the process. On-site maintenance technicians suspected defects in some of the spindle assembly bearings. However, after using CMS to measure key maintenance-related data while the machine was running, analysis showed that the spindle bearings were in fact not the cause of the form errors. As a result, maintenance technicians were able to quickly focus on other areas, saving two working days that would otherwise have been needed to strip down the spindle, along with the associated downtime. The total savings were calculated at €33,600.