Maintenance
Bearing Life Calculator — L10 Rating Life (Hours)
Calculate bearing L10 rating life in hours for dairy plant equipment using dynamic load rating, equivalent load, and speed. Free online bearing life calculator.
Formula
(16667 / speed) * Math.pow(dynamicRating / equivalentLoad, bearingType)
speed
Rotational Speed (rpm)
dynamicRating
Dynamic Load Rating (C) (kN)
equivalentLoad
Equivalent Dynamic Load (P) (kN)
bearingType
Bearing Exponent
Worked Example
1
Given:
bearingType = 3
dynamicRating = 25.5
equivalentLoad = 8
speed = 1450
2
Apply the formula:
(16667 / speed) * Math.pow(dynamicRating / equivalentLoad, bearingType)
3
Result:23760 hours
What is Bearing L10 Life?
L10 life (also called rating life) is the number of operating hours that 90% of a group of identical bearings will complete or exceed before the first signs of fatigue failure appear.
It is the international standard for comparing and selecting bearings for dairy plant equipment such as pumps, separators, conveyors, and fans.
Formula
L10 (hours) = (16667 / n) × (C / P)³
Where:
- n = rotational speed (rpm)
- C = dynamic load rating of bearing (kN) — from bearing catalogue
- P = equivalent dynamic load (kN) — from actual forces on bearing
- Exponent = 3 for ball bearings; use 10/3 ≈ 3.33 for roller bearings
How to Find C and P
- C (Dynamic load rating): Look up your bearing type and number in SKF, FAG, or NTN catalogue
- P (Equivalent load): P = X·Fr + Y·Fa (where Fr = radial force, Fa = axial force; X and Y are factors from catalogue)
L10 Benchmarks for Dairy Equipment
| Equipment | Recommended L10 Life |
|---|---|
| Centrifugal pump | 20,000 – 30,000 hr |
| Separator/centrifuge | 30,000 – 50,000 hr |
| Agitator/mixer | 15,000 – 25,000 hr |
| Conveyor drive | 20,000 – 40,000 hr |
| Fan/blower | 25,000 – 40,000 hr |
Improving Bearing Life
- Correct mounting: Use proper tools; avoid hammering
- Alignment: Misalignment reduces bearing life by 50–80%
- Lubrication: Under/over-lubrication both shorten life
- Contamination control: Keep food-grade grease sealed
- Vibration monitoring: Detect early failure before collapse