Bearings with non-contact seals can be operated at the same speeds as bearings with shields, but with improved sealing effectiveness. The seals form an extremely narrow gap with the inner ring shoulder (fig. 1). Non-contact seals are made of oil and wear-resistant NBR that is reinforced by a sheet steel insert.
SKF deep groove ball bearings with a non-contact seal on one or both sides are identified by the designation suffix RZ or 2RZ.