Previously believed to be only human-made, a natural example of a functioning gear mechanism has been discovered in a common insect -- showing that evolution developed interlocking cogs long before we ...

What is behind this design feature, and is it really all that unusual at all?

Backlash, a clearance between mating gear teeth, is built into speed reducers to let the gears mesh without binding and to provide space for a film of lubricating oil between the teeth. This prevents ...

This article was updated Feb. 28, 2023. It was originally published March 1, 2000. Planetary gears can supply high levels of torque and high-speed reduction. They are also relatively compact compared ...