Seals
Contact or non-contact seals in the rolling bearing protect the bearing against the ingress of contamination and prevent the egress of lubricant from the bearing.Contact seals are normally in contact with the cylindrically ground rib of the inner ring under radial contact force or are guided with contact in a groove in the inner ring. The contact force should be kept small to avoid an excessive increase in frictional torque and temperature.
Contact seals give better sealing effect than non-contact seals (gap seals). The higher coefficient of friction of the contact seal leads to higher bearing temperatures. This restricts the speed of the bearing.
Low-friction sealing of bearing positions with a small radial design envelope, such as bearing positions with needle roller bearings, can be effectively achieved using sealing rings G, GR and SD. These sealing rings can be used individually or in a double arrangement.
Single lip sealing rings GR are suitable for shaft diameters up to 7 mm as standard and have external steel reinforcement for stiffening purposes.
Single lip sealing rings G are designed for shaft diameters over 8 mm and have a rubber-encased steel reinforcement with a rubber wave profile for stiffening.
Double lip sealing rings SD have both a seal lip and a protective lip to act against the ingress of contamination and prevent the escape of lubricant.