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How should I read this graph?

  1. Nov 23, 2014 #1

    The diameter of the shaft is 20 mm, and the circumferencial speed is 1,5 m/s, which i calculated doing

    velocity = angular speed * shaft radius

    The shaft rotates at 1370 rpm.

    The graph should give the permissible speeds for the shaft to rotate at that allow the use of the simmerring made of that material. NBR and FKM are two materials from which their simmerings are made.

    Source: http://www.simrit.com/files/00001387.pdf , p.20
  2. jcsd
  3. Nov 23, 2014 #2

    jack action

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    Science Advisor
    Gold Member

    The rpm lines are there as a convenience so you don't have to do the calculation you did yourself.

    If your case is in the light gray region (which it is), you can safely use the NBR material. If it is in the dark gray region (and I presume the light gray region as well), you can use the FKM material. You cannot use either of them if you are in the blue region.
  4. Nov 23, 2014 #3
    Ahhh got it ! thank you very much
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