NSK presented its new Robustride cylindrical roller bearings for the spindle drives of high speed, high precision machine tools at the recent EMO Hannover Fair, a global event for machine tools and metalworking.
According to the company, these advanced bearings feature an optimised cage that facilitates more even lubricant distribution, which in turn reduces bearing wear, especially under high loads.
Also launched at the show were NSK´s Robust angular contact ball bearings with improved accuracy class. The spindle bearings of machine tools must meet very high requirements for running accuracy.
The company has developed various bearing types and series for this demanding application which are known as the Robust series. The series is now supplemented by the Robustride single-row cylindrical roller bearings. Robustride bearings offer a specially devised cage with geometry and guidance that have been improved specifically for this application profile.
NSK´s optimisation work included developing a way to better distribute the lubricant and, subsequently, create less and more uniform heat generation within the bearing. The lubricant flow in the bearing is directed in such a way that the inside (which is rather disadvantaged by centrifugal forces) is also supplied with lubricant in the optimum way.
“Any resulting surface losses are negligible and, even at the extraordinarily high speeds commonplace in many of today´s machining operations, very good lubricant distribution is achieved,” the company said in a statement.
“These design improvements serve to minimise bearing wear, especially at high loads. They also shorten the running-in period of the bearing grease. Another advantage is that Robustride bearings allow significantly greater tolerances in the bearing clearance due to optimised guidance of the rolling elements, which simplifies mounting procedures.”
In addition, NSK has developed new cages for its series of Robust angular contact ball bearings.