|Seal type||ZZ||Metal shields on both sides.|
|2RS||Rubber seals on both sides.|
|Z||Metal shield on one side.|
|RS||Rubber seal on one side.|
|Tolerances||P0||Normal tolerance level. Is not indicated as a standard.|
|P6||Greater tolerance level than P0.|
|P5||Greater tolerance level than P6.|
Miniature and small bearings are used for extremely high speeds. These bearings offer a low level of noise, vibration, and frictional torque performance.
Miniature and extra-small ball bearings can be sealed by shields or rubber seals to prevent leakage of lubricating grease or entry of dust. Since the appropriate quantity of a high quality lubricating grease is factory sealed, the sealed miniature and extra-small ball bearings allows simpliﬁcation of sealing devices around the bearing and facilitates easy handling.
SEALING AND LUBRICATION
The most popular sizes of miniature and small bearings are also produced in sealed versions. These bearings with Z and ZZ are greased using high quality grease, lubricated for life and suitable for high speeds. Bearings with the suffix RS or 2RS have lip seals on one or both sides made from nitrile butadiene rubber. CRAFT bearings grease is a low noise bearing grease which is thickened by lithium 12-hydroxy stearic, it is made from deeply refined mineral oil with rust and oxidation inhibitors through special technical process. Applied temperatures range -20 C – 120 C.
In general, a ribbon or crown type cage made of steel is used in miniature and small ball bearings.The ribbon type cage is used in relatively large bearing, while the crown type is used in smaller ones.