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The Encyclopedia of Horology

Component record · Power

Reduction Wheel

Partially verified

Large gear

What it does

Increases torque from rotor to mainspring

How it works

Evolution

Standard in automatic movements

Known variations

    Identification for collectors

      Common failure modes

      • Tooth damage

      Diagram

      barrelcentre wheelthird wheelfourth wheelescape wheel
      Schematic: the going train. An outline schematic drawn to show the arrangement of the parts discussed here. It is not a dimensioned working drawing and does not depict a particular maker's calibre.

      Sources & references

      1. de Carle, D., Practical Watch Repairing
      2. de Carle, D., Watch and Clock Encyclopedia
      3. Daniels, G., Watchmaking

      Where sources disagree, the disagreement is stated rather than resolved silently.