Schaeffler proves with its newly-developed, six-row linear recirculating ball bearing and guideway assembly (KUSE) that significant development advances are possible even for well-established products. By improving the infeed zone design on the carriage saddle plates, INA Linear Technology has now succeeded in increasing the load ratings for six-row KUSE linear recirculating ball bearing and guideway assemblies by up to 44% depending on the size and design. As a result, the rating life is three times longer than that of conventional designs. Thanks to the significant increase in performance, the redesigned KUSE series has been awarded the Schaeffler X-life quality mark.
Six-row linear recirculating ball bearing and guideway assemblies in X-life quality have a high level of rigidity and extremely low pulse amplitude. They can now also be used in applications that only tolerate slight vibrations and require very high accuracy, such as in measuring machinery. In general, the recirculating rolling elements prevent a constant number of fully-loaded rolling elements being present in the load zone of the carriages. Depending on the effective number of rolling elements in the load zone, the carriage balances deflections along the stroke to varying degrees. This causes a slight, pulsing equalizing movement in the load direction of the carriage. This kind of movement is called stroke pulsation. Pulse amplitudes of up to 1 µm (peak to peak) for a single ball are not uncommon. For the new KUSE X-life guidance systems, the contour of the infeed zone has been optimized in such a way that the stroke pulsation is considerably reduced, especially at higher loads. At a load of 1.35 tons, the pulsation amplitude is less than 0.1 µm, for example. This is a reduction of 83%.