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 ...

When you push or pull with a simple machine, you are applying a force and doing work. And, if you get more force out of a machine than you put into it, then that machine has a mechanical advantage.

• Planetary units with helical gears, rather than spur gears, have higher torque capacity and run quieter. • Different manufacturers measure and rate backlash in different ways. • Software tools for ...