2 Replies Latest reply on Apr 25, 2010 3:09 AM by Re Ej

    Contact Forces for Spur Gears

    Re Ej

      Hi There!

      I am trying to simulate contact forces resulting from a a pair of meshing spur gears in SW motion,so far no success,I find this link:




      on this link its mention(check the 3rd item in the list) :



      COSMOSMotion users can now simulate the interaction between spur gear, bevel gear pairs and calculate gear teeth contact force using new Gear joint. This new gear joint uses less resources and time than the traditional 3D contact simulation.

      which gear joint is this which give the forces?the gear mate provided in Advance mate just turns the gears but do not care about contact forces so any tutorial or guidance how to simulate the contact forces?Thanks for your time and help!I am using SWP 2009.


        • Re: Contact Forces for Spur Gears
          Ian Hogg

          It would be better if you post motion related questions under motion.


          I don't know who wrote the statement you point to on the web, and while it is sort of true, it is not directly available.

          The gear mate defines the gear ratio coupling between to rotating components. If you apply a torque on one of the shafts, it will scale the torque correctly to give you the reactionary torque on the other shaft. Based on your gear pitch circle, you can then work out what the gear tooth force is (on average)


          In reality for most gears, the tooth force varies with the rolling contact point (radial contact position changes) so you get cyclic variation in the force for each tooth. The only way to accurately get that function is using precise 3D contact since it correctly accounts for the geometry.


          Even in ADAMS where there is a mathematical gear joint, you define the pitch circles and all it does is give you the resulting tooth force at that location (not the detailed force variation with contact point).


          Also remember that mathematical joints ignore gear backlash so if you're concerned with that, 3D contact is the way to go.