Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Simple torsional stress question

  1. Aug 30, 2015 #1
    I am having trouble understanding a relatively simple concept.

    A motor is connected to an impeller directly. i.e Motor -> shaft -> impellers

    A motor is also connected at 90* to an impeller/shaft i.e Motor -> small shaft -> bevel gears (as linked below) -> shaft -> impellers


    Will the torsional stress induced by a load on the impellers be better absorbed in the second instance by the gears thus putting less stress on the motor?
  2. jcsd
  3. Aug 30, 2015 #2


    User Avatar
    Gold Member

    The gears will add a small amount of inertia to the system, but otherwise, the two are identical. There is no useful stress reduction achieved by the gears.
  4. Aug 30, 2015 #3
    Thank you. Is there some sort of literature I can read about a proof for this?
  5. Aug 30, 2015 #4


    User Avatar
    Gold Member

    Why not do your own analysis of the system? Write the equations of motion, draw the stress blocks on the shaft(s) and find the stresses for yourself. That will be the most convincing approach.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook