Drives & Controls April 2024

NSK IS DEVELOPING A “world- rst” technique for diagnosing the remaining life of lubricant grease rapidly and accurately by monitoring how it changes in colour as it ages. A mobile app will allow users to perform on-site analysis of the condition of the lubricants in their bearings and linear motion systems, thus reducing the need for grease inspections and cutting replenishment costs, as well as helping them to implement condition-based maintenance strategies. Grease degrades over time, so on-site inspection of lubricants is essential to maximise uptime and OEE (overall equipment e ectiveness). Industrial companies are increasingly switching from time-based to condition-based maintenance strategies. There is thus a need for an accurate method of diagnosing grease degradation that can be deployed rapidly on site. It would also help to tackle labour shortages and to support carbon neutrality e orts. Existing high-accuracy diagnosis methods rely on laboratory analysis, but this is costly, cannot be used on-site, and entails long waits for results. Visual observation or densitometer methods are therefore more common, but su er from low accuracy. As a result, many users replenish lubricants unnecessarily early to ensure that their machinery continues to operate, thus wasting grease. The new NSK app can analyse the level of lubricant degradation using a small sample of grease. Over time, the grease base oil and additives undergo chemical changes due to oxidation and heat. These changes cause the molecular structure of the lubricant to change and to absorb more shortwavelength light, thus a ecting its colour. Grease is white when new, but turns yellow or orange with use, before eventually becoming black, indicating it has no remaining life. The new app assesses the colour of the grease to calculate how much life it has left. NSK is currently seeking customer feedback on the app before a full-scale launch. TECHNOLOGY n ‘First’ bearing grease degradation app displays remaining life rapidly on-site NSK’s app allows users to monitor the colour of grease on site to determine its remaining life