I'm working with my engineering club at my school and we're looking to design a rocker bogie suspension system like what NASA uses for their rovers. I've found some documentation on the system, but I'm a bit confused on the differential system involved. From my understanding, the system is just two axles, one for the bogies and one for the rocker. The axle connecting the rocker to the chassis runs through the main body and is connected to a differential box in the center so that each side of the rocker axle can rotate freely. My main problem with this, is I can't understand what's keeping the chassis from spinning out. Since the only point of connection seems to be the center axle, what keeps the chassis upright and straight? Does the differential box contribute to this in some way? Or am I missing something?
Also, if anyone could provide any in depth documentation, that would be great. I'm also looking for some good RC sized differentials that could be used for something like this. Any leads would be great. Our club has a 3d printer, but it seems a bit expensive to print something like that. Thanks.