looks fun. what do you want to learn in the simulation?
Don't know what it is but it is interesting.
First i Would check if the two wheels can rotate. When i look at the 2nd and 3rd
lip from the left wheel it seems that they will interfere with the other one, when rotating
What Jared says is true, what do you want to analyze?
Stresses (that is your regular von Mises stress) can be interesting, look and the base of
the teeth where you have made a very big hole (rule of thumb is to never exceed 1/3 of the
widht), in your case the hole is so large that it can be an issue.
but i can also imagine that Herz stresses (contact stress)
can be of importance here too.