How much grease should a bearing have?

The initial grease fill is typically calculated as G = 0.005 × D × B grams, where D is the bearing OD in mm and B is the width in mm. For regreasing, use 50% of this amount. Actual fill percentage depends on speed — 30-50% of free space is common.

What happens if I over-grease a bearing?

Over-greasing causes excessive churning, increased temperature, higher power consumption, and can lead to seal failure and grease leakage. At high speeds, over-greasing is more harmful than under-greasing.

What fill percentage should I use?

For low speed (n×dm 300,000): 25-35%. Sealed bearings from the factory are typically 25-35% filled.

How do I determine the grease volume for relubrication?

For periodic relubrication, use approximately G_regrease = 0.005 × D × B × 0.5 grams. This delivers fresh grease to the contact areas without overfilling the bearing cavity.

Does bearing type affect grease quantity?

Yes. Ball bearings have more internal free space than roller bearings of the same size. The formula G = 0.005 × D × B is a good approximation for all types, but the fill percentage should be adjusted based on bearing type and speed.

免費工程工具 #051

軸承潤滑脂用量計算器

計算滾動軸承建議的潤滑脂填充量。公式：G = 0.005 × D × B。輸入軸承外徑與寬度。

G = 0.005 × D × B公克填充百分比指南

結果

潤滑脂用量（100% 填充）

—

調整後用量（選定填充百分比）

—

補脂量（約為全填充的 50%）

—

體積（約）

—

潤滑脂用量公式

D — 軸承外徑 (mm)
B — 軸承寬度 (mm)
G — 潤滑脂用量（公克）

填充百分比指南

n × d_m	速度等級	建議填充量
< 100,000	低速	50–80%
100,000 – 300,000	中速	30–50%
300,000 – 500,000	高速	25–35%
> 500,000	極高速	20–30%

實務範例

範例 — 6208 深溝球軸承

已知： D = 80 mm, B = 18 mm

G = 0.005 × 80 × 18 = 7.2 克 （100% 填充）

40% 填充時：7.2 × 0.40 = 2.9 克

補充潤滑脂：7.2 × 0.50 = 3.6 克

⚠️ 注意： 潤滑脂過量是導致潤滑脂相關軸承故障的首要原因。如有疑慮，請減少潤滑脂用量，並依賴適當的再潤滑間隔。