Additional information for specific bearing types and performance classes
Hybrid bearingsThe higher values for the modulus of elasticity of rolling elements made of silicon nitride decreases the contact area in the raceways to significantly reduce rolling and sliding friction. Additionally, the lower density of ceramic rolling elements, when compared with steel, reduces the centrifugal forces, which also may reduce friction at high speeds.
Standard hybrid ball bearingsUsing the equations given under The SKF model for calculating the frictional moment, the frictional moment for hybrid angular contact ball bearings can be calculated by multiplying the geometric constants R3 and S3 of the all-steel bearings by a factor 0,41 (that is 0,41 R3 and 0,41 S3, respectively).
Hybrid deep groove ball bearings in high speed applications are usually preloaded axially. Under these conditions, hybrid deep groove ball bearings behave like angular contact ball bearings with a similar reduced frictional moment. SKF recommends contacting the SKF application engineering service when calculating the frictional moment for hybrid deep groove ball bearings.