Back-driven Gearbox and motor

[PendGB]

What kind of gearbox is best for being back-driven? The driving torque would be quite small, to the point where the motor's rotor inertia needs to be taken into account. I wouldn't want a reduction ratio any greater than 20:1. I was informed that a cycloidal drive may be the way to go but I was hoping for a second opinion.

Thanks!

 

[BrianPetersen]

Wind-up watches do pretty well with ordinary spur gears. I have no idea what the speed-increase ratio is between the energy-storage spring and the second hand is, but it's gotta be huge.

Or maybe you have a different application?

(more information = better answers)

 

[Compositepro]

When you say back driven I assume you mean you want to increase rpm. Reduction ratio 20:1 implies the opposite. You mean multiplication ratio. Simple spur gears place a significant load on the gear bearings and this increases friction, which is particularly important in high speed drives. Cycloidal, and planetary work well. High speed grinders use a large crowned drive pulley and a small driven pulley with a thin flat belt. These flat belts a have low energy losses.