How does a mechanical watch movement work? A brief explanation
What is a mechanical movement?
A mechanical movement measures and displays the time using purely physical principles. The energy is supplied by a mainspring, which is wound either by hand (manual winding) or by the movement of the wrist via a rotor (self-winding movement).
The four basic components
- Mainspring: stores the driving energy; maximum running time = power reserve (usually 38–70 hours)
- Gear train: transmits and distributes the energy in a controlled manner
- Escapement: breaks down the flow of energy into precisely timed pulses (the ‘ticking’)
- Balance wheel: oscillates at a fixed frequency (usually 4–5 Hz), thereby setting the tempo
Process: Wind the mainspring → Gear train distributes power → Escapement regulates the timing → Balance wheel regulates → Hand train displays the time.
Automatic vs. manual winding
| Feature | Manual winding | Automatic |
| Power source | Crown wound by hand | Rotor driven by arm movement |
| Components | less | additional rotor |
| Day-to-day use | needs to be wound up regularly | winds itself up when worn |
Why mechanical watches are never 100% accurate
Temperature, position, magnetic fields and wear and tear have a minimal effect on the balance wheel. For this reason, a deviation of just a few seconds per day is already considered very precise – quartz watches are technically superior in this respect, whilst mechanical watches score points for their craftsmanship and durability.
Frequently Asked Questions (FAQ)
How often does a movement need servicing?
A service is recommended every 4–7 years.
Is an automatic watch more accurate than a hand-wound one?
No, accuracy depends on the escapement and balance wheel, not on the winding system.
Why do magnetic fields affect timekeeping accuracy?
They influence the balance spring, thereby altering the oscillation frequency.
Conclusion
The mainspring, gear train, escapement and balance wheel transform stored energy into a precise, consistent time display – a small mechanical masterpiece that, with proper care, will last for generations.
