ベアリング寿命計算機
動的負荷定格、等価負荷、回転速度からボールベアリングまたはローラーベアリングのL10基本定格寿命（ISO 281）を計算します — 百万回転、時間、および実際の運用サイクルでのカレンダー寿命で表示。
入力
L10計算式に使用される指数pを設定します。
ベアリングのデータシートから、kN単位（または任意の単位 — C/Pの比率のみが重要）。
ベアリングにかかる実際の負荷（またはラジアル+スラスト等価の組合せ負荷）、Cと同じ単位。
定格時間を実際の運用サイクルでのカレンダー寿命に変換するために使用します。
出力
| Quantity | Value |
|---|---|
| No data yet | |
ガイド
Every rolling-element bearing has a fatigue life, not just a static failure point — even correctly loaded, its rolling surfaces eventually flake from cyclic contact stress. The L10 basic rating life from ISO 281 is the industry-standard way to predict when: the number of revolutions (or hours) 90% of an identical batch of bearings will reach or exceed before the first sign of fatigue.
How to use it
- Pick ball or roller bearing — this sets the life exponent used in the formula.
- Enter the dynamic load rating (C) from the bearing's datasheet and the equivalent dynamic load (P) actually applied to it. Only their ratio matters, so any consistent unit (kN, lbf) works.
- Enter the rotational speed in rpm.
- Enter operating hours per day — a bearing rated for thousands of hours means something very different run 24/7 versus one 8-hour shift, and this converts the rated hours into an actual calendar service life.
The formula
L10 = (C ÷ P)^p— basic rating life in million revolutionsL10h = L10 × 10⁶ ÷ (60 × n)— in hours, at speednrpmp = 3for ball bearings,p = 10/3for roller bearings
L10h is then divided by your daily operating hours to give a calendar service life in days and years.
Why "L10" and not just "life"?
Bearing fatigue is statistical, not a fixed wear-out point — nominally identical bearings under identical load fail at different times. L10 is the life at which 10% of a population has failed (90% survive), the conventional design figure. Some manufacturers also publish a "modified" rating life (L10a, using ISO 281's a1/aSKF factors for reliability, material, and lubrication) that pushes the number higher under good operating conditions — this calculator gives the baseline L10 that those adjustments build on.
What if my load varies over the cycle?
Use the equivalent dynamic load P, not the peak — for radial and axial (thrust) loads combined, P is typically P = XFr + YFa using the bearing's own X/Y factors from its datasheet. For a duty cycle with distinct load/speed phases, calculate a weighted mean cubic load first, then use that as P here.
Privacy
Everything is calculated in your browser. No values are sent to a server.
Related tools
For selecting a compatible shaft and torque rating around the bearing, see the Shaft Power & Torque Calculator. For the gearing feeding into the shaft, use the Gear Ratio Calculator.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/bearing-life-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"bearingType": "ball",
"dynamicLoadRating": "25",
"equivalentLoad": "5",
"speed": "1500",
"hoursPerDay": "24"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `bearing-life-calculator` tool (Bearing Life Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.