Simulate a Planetary Gear in MDX

[Nick]

I have built a model of a planetary gear set in Pro/E and correctly (I believe) modeled the connections. However, when it comes to defining the gear meshes, I have no problem with the sun to planet gears since they are both supported by the planetary carrier, but the planet to "universe" gear connection do not share a common carrier. As a result, the relative motion between the planet gears and the universe gear is not correct, it skips teeth. Does anyone have any experience with this? Any tips would be appreciated. Thank you.
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[AndyDeighton-di]

The problem is that the annulus or "universe" gear is internal, and you cannot specify that in a gear connection, and so the planet/annulus mesh rotates in the wrong direction. I overcame this by making a dummy idler gear between the planet and annulus. To do this I created an axis on the carrier at the mesh point between the planet and annulus (at the planet PCD). I made a new idler gear part which is simply datum planes and an axis. Assemble the idler onto the carrier idler axis described above. Create a gear connection between the planet and the idler with a 1 to 1 ratio, create a gear connection between the idler and annulus with the correct ratio of planet teeth to annulus teeth. Works nicely.

[Nick]

Thank you! I look forward to trying this.