Glossary
Equivalent bearing load P
Äquivalente Lagerbelastung P
The equivalent bearing load P converts a combination of radial and axial forces into a single substitute load with the same effect on bearing life as the actual load combination. It follows the basic formula P = X·Fr + Y·Fa, with factors X and Y depending on bearing type, contact angle and the axial-to-radial load ratio, as tabulated in manufacturer catalogues.
Together with the dynamic load rating C, P feeds the ISO 281 life calculation via the ratio C/P. For static analysis, an equivalent static load P0 is formed analogously. Because the life exponent amplifies errors, underestimating the real forces leads to significantly shorter actual service life than calculated.