speed difference formulation in a planetary gearset

[soundara]

Hello there,

I have a planetary gear set where the input is the ring gear and output is the planetary gear...none of the gears are fixed...but the shaft of the sun gear experiences resistance to its motion as a result of spinning inside a viscous fluid. The gear ration...zring/z sun = 2.7

Can you please help me in formulating a general equation for planetary gearing systems that would give me a relation between the speed difference (planet speed - sun speed) as a function of (planet speed - ring speed).
The general equation goes like (nsun + gearratio*nring- (1+gearratio)*nplanet).How do i reach the required formulation from this...

thanks

regards,
soundara

 

[Matt51]

Is this a simple planetary? the general eqn for a simple planetary is ws = -(alpha)(wr)+[(1+alpha)wc] where alpha is R/S.
The eqn for the planet speed is:
wp=[(2)(alpha)wr+{(1+aplha)/(1-alpha)]wc

now you can subtract the two and get wp-ws =