VoltCheck24 Rotating Machinery Calculator
Estimate basic dynamic fatigue rating life (L10 / L10h), dynamic equivalent load P = X·Fr + Y·Fa, and recommended grease lubrication intervals for deep groove ball bearings and roller bearings.
Basic rating life in operating hours is given by: L10h = (10^6 / (60 · n)) · (C / P)^p, where n is rotational speed (RPM), C is basic dynamic load rating (kN), P is dynamic equivalent load (kN), and exponent p = 3 for ball bearings (p = 10/3 for roller bearings).
Bearings subjected to both radial load (Fr) and axial thrust load (Fa) calculate equivalent load as P = X · Fr + Y · Fa, factoring contact angle and radial/axial ratio (Fa / Fr > e).
Vibration velocity above 4.5 mm/s (RMS) on industrial pumps and electric motors signals significant bearing wear or unbalance. Above 11.2 mm/s represents extreme danger of catastrophic drive shaft seizure.
L10h represents the number of operating hours that 90% of a group of identical bearings will achieve or exceed before the first evidence of material fatigue flaking appears.
Over 80% of premature bearing failures stem from inadequate or contaminated lubrication, over-greasing leading to churn overheating, misalignment, and electrical shaft currents (VFD EDM fluting).