Free Engineering Tool
Roller Chain Defect Frequency Calculator
Calculate tooth meshing frequency, chain link frequency, driven speed, and harmonics for roller chain drive systems.
Results
Tooth Meshing Harmonics
| Harmonic | Frequency (Hz) | CPM | Note |
|---|
Tooth Meshing Frequency
The tooth meshing frequency (TMF) is the rate at which chain links engage with sprocket teeth:
- Z₁ — number of teeth on driving sprocket
- n₁ — driver shaft speed (RPM)
Chain Link Frequency
The chain link frequency represents one complete revolution of the chain loop:
- Nlinks — total number of chain links
Driven Speed
Vibration Indicators
| Frequency | Source | Indication |
|---|---|---|
| 1× TMF | Tooth engagement | Normal chain operation, polygonal effect |
| 2×, 3× TMF | Harmonics | Chain wear, worn sprocket teeth, excessive slack |
| 1× chain link freq | Chain revolution | Single defective link, tight link |
| Sidebands around TMF | Modulation | Worn/elongated chain, misalignment |
Given: Z₁ = 17, Z₂ = 51, Links = 120, n₁ = 1450 RPM
TMF = 17 × 1450 / 60 = 410.83 Hz
Chain freq = 17 × 1450 / (60 × 120) = 3.42 Hz
Driven speed = 1450 × 17/51 = 483.3 RPM
Speed ratio = 17/51 = 0.333
⚠️ Note: For sprockets with fewer than 21 teeth, the polygonal (chordal) effect becomes significant, producing higher TMF harmonics even in healthy chain drives. Use 21+ teeth sprockets when smooth operation is critical.
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Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
