Manufacturing Micro-gears for watch and medical industries

Mimotec produces a wide variety of cogwheels, pinions, gears with backlash adjustment, and non-circular gears. These can be used for mechanical watch movements, as well as for micro-reducers or micro-pumps for the medical industry (e.g. insulin pumps).

The great advantage of UV-LIGA technology or electroforming technology is that it can produce gears that strictly adhere to the theoretical profile. Whether external, internal, or backlash-compensated, these gears are characterised by circularity and coaxiality between the central hole and the tooth head in the micron range.

The UV-LIGA process is perfectly suited to producing micro-gears. The smallest gears can reach a diameter of around 700µm, with a thickness of 400µm.

It is also possible to produce a gear coupled to a pinion or cam in one piece. This simplifies assembly operations considerably and guarantees perfect indexing of one in relation to the other.

Our additive manufacturing technique offers a choice of hard nickel-based stainless materials such as Ni, NiP (100% non-magnetic), and NiFe, as well as hard Au24 carat (220HV).

Combined with a polished surface finish of the functional surfaces (Ra 15–20nm) and a high hardness ranging from 540HV to 610HV, micro-gears produced by UV-LIGA technology offer good wear resistance.

All of our components are manufactured based on drawings provided by our customers. Thanks to the great design freedom of our process, we are able to produce customised tooth structures to meet the specific requirements of your applications. As the examples below illustrate, the only limit is your imagination.

Example of gearing for micro-annular gear pump applications which allow very precise flow control.

Micro-gear with external and internal teeth, planet-type, offering very high precision teeth structuring as well as perfect coaxiality (+/-1µm).

Double-stage micro-toothing with specific structures and perfectly angularly aligned with each other.

It is also possible to combine a dual function in one component. This example from watchmaking shows a cogwheel and a one-piece cam.This solution removes the assembly process and guarantees the perfect alignment of the cam and the wheel.

This asymmetrical split gearing structure eliminates backlash in motion transmission when changing direction.

The flexible section is achieved with a thin blade of 20µm, which can be up to 200µm thick.

This type of structure is only possible with our manufacturing method.