1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Planetary spur gear problem!

  1. Nov 27, 2011 #1
    1. The problem statement, all variables and given/known data

    I am doing this gear problem, I have attached the question and how I've started this off I am having problems working it all out as the question said I should try and have the casing rotating at a speed of 15-25 rpm.

    I have, these gear sizes which were obtained from a manufacturers catalogue.

    TB = 36
    TC = 24
    TD = 40
    TE = 80
    NX = 100 rpm
    NY = 350 rpm

    3. The attempt at a solution

    To work out the number of teeth on casing F, from the geometry of the figure
    dF/2 = dE/2+dB
    so dF= dE + 2dB
    dF= 80+ 2(40) = 160 teeth.

    Using my my table of motion which I have attached for the speed of gear F, there is a mistake on it as the 2 TC's cancel out to end up y-x*(TB/TF) I have used the input speed for x and the output speed for y so my equation works out as 350-100 * (36/160) = 327.5 rpm this is obviously very wrong. Where have I went wrong? Have I started at the wrong point?

    Thanks in advance.

    Attached Files:

  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted