What is tooth meshing frequency in a chain drive?

Tooth meshing frequency (TMF) is the rate at which chain links engage with sprocket teeth. It equals the number of teeth on the driving sprocket multiplied by the shaft rotational frequency: TMF = Z1 × RPM / 60. This frequency is a dominant vibration source in chain drives and increases with worn or damaged teeth.

What is chain link frequency?

Chain link frequency is the rate at which one complete revolution of the chain occurs. It equals the tooth meshing frequency divided by the total number of links: f_chain = Z1 × RPM / (60 × N_links). A defect on a single chain link will produce vibration at this frequency.

How do I diagnose chain wear from vibration?

Chain wear typically increases the amplitude of tooth meshing frequency and its harmonics. A worn or elongated chain may also produce sidebands around TMF spaced at chain link frequency. Impact-type vibration from loose chains produces broadband noise with elevated TMF harmonics.

What causes chain drive vibration?

Common causes include chain wear and elongation, misaligned sprockets, improper chain tension, worn sprocket teeth, damaged or stiff chain links, and chordal action (polygonal effect). The polygonal effect is inherent to chain drives and produces vibration at tooth meshing frequency.

What is the polygonal effect in chain drives?

The polygonal (chordal) effect occurs because a chain wraps around a sprocket as a polygon rather than a smooth circle. This causes periodic speed variation at the tooth meshing frequency. The effect is more pronounced with fewer teeth on the sprocket and can be reduced by using sprockets with more teeth (≥21).

免費工程工具

滾子鏈故障頻率計算器

計算滾子鏈傳動系統的齒嚙合頻率、鏈節頻率、從動轉速及諧波。

滾子鏈齒嚙合鏈節頻率

結果

齒嚙合頻率

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鏈節頻率（1 鏈迴轉）

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驅動軸頻率

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被驅動端轉速

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速比 (Z₁/Z₂)

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齒嚙合諧波

諧波	頻率 (Hz)	CPM	注意

齒嚙合頻率

齒嚙合頻率 (TMF) 是鏈節與鏈輪齒嚙合的速率：

Z₁ — 主動鏈輪的齒數
n₁ — 驅動軸轉速 (RPM)

鏈節頻率

鏈節頻率代表鏈環的一次完整迴轉：

N_鏈節 — 鏈節總數

被驅動端轉速

振動指標

頻率	來源	指示
1× TMF	齒嚙合	正常鏈運轉，多邊形效應
2×, 3× TMF	諧波	鏈磨損、鏈輪齒磨損、過度鬆弛
1× 鏈節頻率	鏈迴轉	單一故障鏈節、緊鏈節
TMF 周圍的邊帶	調變	磨損/伸長鏈、不對心

範例 — 17/51 鏈傳動

已知： Z₁ = 17, Z₂ = 51, 鏈節 = 120, n₁ = 1450 RPM

TMF = 17 × 1450 / 60 = 410.83 Hz

鏈頻率 = 17 × 1450 / (60 × 120) = 3.42 Hz

從動轉速 = 1450 × 17/51 = 483.3 RPM

速比 = 17/51 = 0.333

⚠️ 注意： 對於少於 21 齒的鏈輪，多邊形（弦線）效應變得顯著，即使在健康的鏈傳動中也會產生較高的 TMF 諧波。當平穩運轉至關重要時，請使用 21 齒以上的鏈輪。