Im trying to model as accurately as I can I am trying to figure out how this is supposed to work. Im not engineer.

What is throwing me off is the plastic parts the gears fit in it looks like they lock all the gears in? How is this in principle supposed to work. Do the 4 small gears lock in place and the two side ones rotate? or do they only lock at a certain stage? are the two side gears suppose to lock or do they spin freely? or do they all spin freely? If so why do the plastic parts have the nudges in them? Whats the purpose of the 85442 part that gear mounts to? Or does only the right side gear lock in place to 85426 which in turn locks to the big 8648 gear and the  gear on the left spins inside the other half of the chamber? The 4 small gears in the center do they spin or not? or only 2 spin and 2 dont?