MOTIONSOLVE/MOTIONVIEW Why do my gears seems bouncing when they mesh?

Dumberoo
Dumberoo Altair Community Member
edited August 2021 in Community Q&A

Hello Everyone. 

I have a gear setup in motionsolve/motionview. I used tranmission gears up to the differential.


I used RIGID 3D Contacts for the gears. Once i solved it, the gears doesnt produce a smooth transmission of motion. The only gear that shows smooth rotation is the Pinion gear which is attached to the motor (the gear that I applied MOTION (700RPM)) 

What i Mean is, the Pinion Gear Shows a uniform angular motion 700RPM but the succeeding gears seems bouncing with each other and produces a non constant speed. (its like rotate- then stop then rotate again then stop). I thought of editing the CONTACT from IMPACT to POISSON and Reduce Coefficient of Restitution to avoid the bouncing but Im not sure if what im doing is correct.


How to avoid this? Thank you for your answer. GodBless

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Answers

  • AnanthK
    AnanthK
    Altair Employee
    edited August 2021

    Some things to check: 

     

    1) Is this purely a visual effect or actually something you see in the data? Animations can be deceiving particularly with rotating parts and animation frame rates. 

    2) Have the 3D contacts gone through a thorough check for meshing errors and element normals? Mesh quality obviously affects 3D contact results - you may have to manually mesh the geometry in Hypermesh in extreme cases. 

    3) Are there any redundant constraints in the model? Check the log file for this. If constraints are being randomly removed by MotionSolve this will result in strange results. This can be resolved by one of 3 methods - use a different combination of joint constraints that allows the correct DOF for the system, or use compliant joints with high stiffness, or use flexbodies for some of the shafts that are otherwise over-constrained. 

    4) How good is the CAD data? If there is initial interference or the geometry is not close to perfect, 3D contact will not work as intended.  

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