Cartridge units are protected on both sides with laminar rings (fig. 4) to prevent both the ingress of contaminants and the egress of grease. These seals do not limit the attainable speed for the single direction angular contact thrust ball bearings within the unit.
- –40 to +120 °C (–40 to +250 °F) for single direction bearings
- –55 to +110 °C (–65 to +230 °F) for double direction bearings
Under normal operating conditions, the service life of the initial fill will outlast the bearing. If double direction bearings have to accommodate heavy loads and run for long periods at high speeds, relubrication may be necessary. When relubricating, the grease should be applied slowly while the bearing is rotating at normal operating temperature. Excessive pressure should be avoided as this could damage the seals.
Sealed bearings should not be washed or heated to temperatures above 80 °C (175 °F). If a sealed bearing is to be heated for mounting, an induction heater must be used and the bearing should be fitted immediately.