What is L10 bearing life?

L10 life is the basic rating life defined by ISO 281 — the number of revolutions (or hours at a given speed) that 90% of a group of identical bearings will complete or exceed before the first evidence of fatigue damage appears. In other words, there is a 10% probability of failure before L10 is reached.

What is the difference between basic and modified rating life?

L10 is the basic rating life based on C/P and the life exponent. ISO 281 expresses modified rating life as Lnm = a1 × aISO × L10, where a1 accounts for the selected reliability and aISO for operating conditions including lubrication, contamination and fatigue load limit. This calculator computes only basic L10 life.

Why is the life exponent different for ball and roller bearings?

The life exponent p reflects the contact geometry. Ball bearings have point contact (elliptical contact area), giving p = 3. Roller bearings have line contact (rectangular contact area), giving p = 10/3 ≈ 3.333. The higher exponent for rollers means their life is more sensitive to load changes. These values are established in ISO 281.

How do I determine the equivalent dynamic bearing load P?

The equivalent dynamic load P combines radial (Fr) and axial (Fa) forces into a single value that would give the same bearing life. For radial bearings: P = X·Fr + Y·Fa, where X and Y are factors from the bearing catalog depending on the contact angle and Fa/Fr ratio. For purely radial loads, P = Fr. Always consult the bearing manufacturer's catalog for exact X and Y values.

What L10h value should I require?

There is no universal acceptable L10h value. The required rating life must come from the machine specification and risk assessment, considering duty cycle, reliability target, maintenance strategy and the bearing manufacturer’s application guidance. Basic rating life is not a guarantee of service life.

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軸承 L10 壽命計算器

根據 ISO 281 計算軸承基本額定壽命 L10。輸入動額定負荷 C、當量動負荷 P、軸承類型及轉速。

ISO 281:2007 滾珠與滾子 L10 / L10h

結果

基本額定壽命 L₁₀ₕ

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L₁₀ (百萬轉)

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L₁₀ (年，24/7 運轉)

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C/P 比值

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壽命指數 p

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基本額定壽命 (ISO 281)

以轉數表示的基本額定壽命：

以小時表示的基本額定壽命：

C — 來自軸承目錄的基本動額定負荷 (kN)
P — 當量動軸承負荷 (kN)
n — 轉速 (RPM)
p — 壽命指數： p = 3 適用於滾珠軸承， p = 10/3 適用於滾子軸承

選擇所需壽命

ISO 281 提供壽命評定計算，並非針對每種機器類型設定通用最低壽命。請根據機器規格與風險評估，結合實際工況週期、可靠度目標、維護策略及軸承製造商之應用指引，選擇所需壽命。

範圍： 基本壽命評定為常規條件下的統計疲勞評定。ISO 281 並未涵蓋所有使用壽命終結之成因；磨損、腐蝕與電蝕可能導致使用壽命提前終結。

實務範例

計算範例 — 目錄額定值與負荷

已知： C = 42.3 kN, P = 8.5 kN, 轉速 = 1500 RPM, 球軸承 (p = 3)

C/P = 42.3 / 8.5 = 4.976

L₁₀ = (4.976)³ × 10⁶ = 123.24 × 10⁶ = 123,244,000 rev

L₁₀ₕ = 123,244,000 / (60 × 1500) = 1,369 小時

ℹ️ 注意： 此計算器僅計算基本 L₁₀ 壽命。ISO 281 將修正壽命表示為 L_nm = a₁ × a_ISO × L₁₀，係數依據所需可靠度與運轉條件選取。