What is the bearing equivalent dynamic load P?

The equivalent dynamic load P is a hypothetical constant radial load that would give the same bearing life as the actual combined radial and axial loads. It is calculated as P = X·Fr + Y·Fa, where X and Y are load factors depending on the bearing type and load ratio.

What are the X and Y factors?

X is the radial load factor and Y is the axial load factor. They depend on the bearing type and the ratio Fa/Fr relative to the e-value. When Fa/Fr ≤ e, the axial load has negligible effect (X=1, Y=0). When Fa/Fr > e, both X and Y apply.

What is the e-value in bearing calculations?

The e-value is a threshold ratio specific to each bearing type. It determines whether the axial load significantly affects bearing life. When Fa/Fr exceeds e, the Y factor must be applied to account for the axial load contribution.

How do I handle pure radial load?

For pure radial load (Fa = 0), the equivalent load simplifies to P = Fr. No axial factor applies, and you can use the radial load directly in the L10 life calculation.

Can I use this for static equivalent load P0?

This calculator computes the dynamic equivalent load P for life calculations. For static equivalent load P0, the formula is similar but uses different X0 and Y0 factors. Use the Bearing Static Safety Factor calculator for P0 assessment.

免費工程工具 #046

軸承當量動載荷計算器

計算當量動軸承載荷 P = X·F_r + Y·F_a. Automatically selects X,Y factors based on bearing type and F_a/F_r 比值與 e 值自動選取 X、Y 係數。

P = X·Fr + Y·Fa e 值檢查自動選取 X、Y

徑向載荷 F_r (kN)

軸向載荷 F_a (kN)

軸承類型

快速預設

結果

當量動載荷 P

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Fa/Fr 比值

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e 值閾值

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使用係數 (X, Y)

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載荷條件

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當量動載荷

當量動軸承載荷將徑向與軸向力合併為單一數值：

條件為：若 F_a/F_r ≤ e，則 P = F_r。若 F_a/F_r > e，則 P = X·F_r + Y·F_a.

依軸承類型的 X、Y 與 e 係數

軸承類型	e	X (Fa/Fr ≤ e)	X (Fa/Fr > e)	Y (Fa/Fr > e)
深溝球軸承 (DGBB)	0.19	1	0.56	2.30
角接觸球軸承 15°	0.38	1	0.44	1.47
角接觸球軸承 25°	0.68	1	0.41	0.87
角接觸球軸承 40°	1.14	1	0.35	0.57
調心球軸承	0.40	1	0.65	1.71
圓柱滾子軸承	—	1	—	—
調心滾子軸承	0.37	1	0.40	1.60
球面滾子軸承	0.27	1	0.67	2.35

ℹ️ 注意： 上述數值為簡化的典型值。精確的 X、Y 和 e 值取決於具體的軸承型號以及 C₀/F_a。請參閱製造商目錄以獲取精確數值。

實務範例

範例 — 深溝球軸承 6208

已知： F_r = 8 kN, F_a = 3 kN

F_a/F_r = 3/8 = 0.375 > e = 0.19 → 軸向負荷顯著

P = 0.56 × 8 + 2.30 × 3 = 4.48 + 6.90 = 11.38 kN