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Shaft Sizing

  1. Feb 21, 2012 #1

    I was hoping that somebody would be able to help me.

    I need to size a shaft coming from a turbocharger spinning at 150,000rpm the shaft needs to transmit 9Nm and 200mm in length, the shear stress of the material is 457MPa.

    I need to size the diameter of the shaft and know that it is going to be very small but cant seem to find a formula that gives me a sensible answer, right now I am using a formula from engineering toolbox (http://www.engineeringtoolbox.com/torsion-shafts-d_947.html)

    D = 1.72 (Tmax/σmax)1/3

    But this give me a diameter of 0.46mm which seems so small that it would just twist and break.

    an y help greatly appreciated.

  2. jcsd
  3. Feb 21, 2012 #2


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    Hi Max. Check your work again. I'm getting 4.65 mm.
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