Radial ball-bearing differential


The Dara differential is based on a compact modular design in which the two inputs to the differential gear are connected to the teeth of the barrel-drum and to those of the ratchet wheel; the output from the differential is linked to the power reserve indicator.

Patent number: EP1995649A2


  • Independent, reliable module, ready to be integrated into the movement
  • No friction adjustment
  • No play adjustment
  • Very compact – d 0.50 x D 4.20 x Th 1.00 mm
  • Lubrication-free


  • Product data sheet – Dara
  • SSC Publication – Dara

Everything to develop your radial ball-bearing differential

Do you want to develop your solution adapted to the special features of your construction based on Dara? To follow our design process, you can go to the next step and view the references for our radial ball-bearing differential.

A team listening to your concerns

Traditional differential systems in watchmaking generally need a watchmaker to make the sensitive friction adjustment when assembling the movement.

Our engineers have designed a preset independent module offering precision and reliability to implement the power reserve indicator function.

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