I designed an internal spur gear without using the solidedge integrated gear application. When I set rotational motor to the pinion, rather then following the gear, it rotates on its own axis. I can not choose the gear so pinion can follow its path.
These are fun and IMO Solid Edge does a good job with this sort of thing. I didn't work up a pretty animation, I don't have the knack/patience for rendering to make it look good. But this will get you the concept.
The key is to have the necessary third member, the carrier that holds the planet gear in its orbit. a couple axial aligns on that part, one to the ring gear and the other to the planet. Then SE takes care of the rotation relation with the rotation command that you showed, between the ring and the planet, enter the number of teeth on each and I usually have to flip rotation and flip the tooth count between the two because I get it wrong the first time.
Those who know me question the assigned user rank.