A number of key improvements to the online engineering tools provided by NSK, a global leader in motion control solutions, serve to boost the work efficiency of customers. For instance, easy-to-use tools such as NSK Online Catalogue, Technical Calculations and 2D/3D CAD Data (all previously independent) are now linked. Design engineers can therefore select bearings, confirm specifications and download CAD data as part of a one-stop solution. In another improvement, a new function in Technical Calculations allows the one-time calculation and display of multiple factors that include bearing life, bearing fits/clearances and bearing frequencies, again helping NSK customers to reduce their work time.
A notable underlying change is the application of NSK’s revised basic dynamic load ratings, a parameter used to calculate the estimated life of rolling bearings. The revision, which extends the basic rating life for the company’s main types of rolling bearings, including include deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, cylindrical roller bearings and tapered roller bearings, now feature in the NSK Online Catalogue.
The new estimates derive from applying NSK’s highly accurate (patent-pending) bearing life prediction method based on ultrasonic testing, a world-first process announced by the company in March 2023. NSK developed a quantitative evaluation method that can determine which factors influence the process of crack propagation in a bearing material, and to what extent.
By combining the new method with an ultrasonic inspection technique that scans the non-metallic inclusions in a large volume of steel, the company is able to predict bearing life with far higher accuracy. NSK has therefore revised the basic dynamic load rating of many bearings with no change in design or materials, while still applying the appropriate safety margin to any uprated values. With this revision, the estimated life of radial roller bearings, for example, is up to twice that of previously.
As the basic dynamic load ratings of bearings improves, they are suitable for use in higher load conditions, facilitating the selection of smaller bearings that perform the same function. Benefits include machine downsizing and weight reduction. By way of example, machines that used NSK’s HR32306J tapered roller bearing can now adopt the smaller HR33206J. This change delivers a 14% reduction in bearing outside diameter, a 13% reduction in width and approximately 38% less weight.
Those seeking carbon neutrality also gain. Smaller bearings require fewer resources to manufacture. They also yield lower torque, resulting in less power consumption and fewer CO2 emissions during use. With the same aforementioned change of bearing, users will see a reduction in bearing torque and power consumption of approximately 18% (around 48 kWh per annum). According to NSK calculations, this converts to approximately 22 kg of CO2 emissions savings.