Peter.

10-31-2009, 08:44 PM

I've been checking out this site and I'm struggling to understand the formulas, could someone run me through it please?

http://www.roymech.co.uk/Useful_Tables/Drive/Epi_cyclic_gears.html

I have an epicyclic gearbox that I want to figure the ratio for. It looks like exapmple 1 on that page. On my gearbox, S is the input shaft, L is the output and A is fixed.

Input gear S has 9 teeth

Planet gears P have 17 teeth

Annular gear A has 45 teeth.

From turning the input and watching the output I can see my ratio is about 6:1

I have another which is much lower geared and has the following values:

S=8

P=28

A=64

What formula should I use?

http://www.roymech.co.uk/Useful_Tables/Drive/Epi_cyclic_gears.html

I have an epicyclic gearbox that I want to figure the ratio for. It looks like exapmple 1 on that page. On my gearbox, S is the input shaft, L is the output and A is fixed.

Input gear S has 9 teeth

Planet gears P have 17 teeth

Annular gear A has 45 teeth.

From turning the input and watching the output I can see my ratio is about 6:1

I have another which is much lower geared and has the following values:

S=8

P=28

A=64

What formula should I use?