Planetary sizing
Planetary sizing
(OP)
Hi,
I am sizing planetary gear set for an automotive transmission using KISSsys. But when I use its rough sizing feature I get large number of teeth on sun gear as compared to planet gears. My previous experience is always sun gear teeth are lower than planet gears. So wanted to understand if anybody has better approach for deciding no of teeth of planetary gear set.
Thanks
Sachin
I am sizing planetary gear set for an automotive transmission using KISSsys. But when I use its rough sizing feature I get large number of teeth on sun gear as compared to planet gears. My previous experience is always sun gear teeth are lower than planet gears. So wanted to understand if anybody has better approach for deciding no of teeth of planetary gear set.
Thanks
Sachin





RE: Planetary sizing
I don't think I've ever seen an automotive planetary gear set in which the sun gear did not have more teeth than each of the planet gears.
Usually there is at least one concentric shaft going up the middle of that planetary set, often two or three, so having a decent amount of diameter to the sun gear helps to make room for that!
http://www.thetruthaboutcars.com/2014/02/ur-turn-s...
RE: Planetary sizing
Yes, my previous experiece has been with planetary design of tractor transmissions as a final rediction ratio. Where we had sun gear teeth cut on the sunshaft and we always had configurations where sun teeth were lesser than planet. But as you say it is not the case most of the time in automotive transmissions.
I have a reduction ratio to be achived in tha range of 9 to 9.5. I am using two planetary in line with each set gving reduction of around 3.0. I am locking ring gear in both sets.Input is given to sun gear. Power is taken out from forst planetary carrier and is input to secong sunshaft.
RE: Planetary sizing
They offer tutorials and help in learning how to operate the software.
RE: Planetary sizing
RE: Planetary sizing
RE: Planetary sizing
RE: Planetary sizing
Thanks you.
RE: Planetary sizing