I am still not understanding your diagram lol.Here's a mechanism which I think would work. You could have the central oval cam (which doesn't rotate) rock back & forth to change direction.
View attachment 285697
I am imagining the piston to the right of the wheel, pushing the pin to the left. The pin interferes with the fixed cam, so cannot move past it. The pin is in a slider. The image is the 4 stages of half a stroke, and it behaves the same on the way back.
The idea is to have a mechanical movement where the first parts of the pistons stroke are converted into non-linear motion - in this case, the pin is deflected sideways by the central cam, and starts the wheel rotating anti-clockwise. At the start of each rotation, the pin slides along the cam and starts the wheel going in the correct direction.
These are my questions on the first diagram also:
This implies that the concept is mathematically possible.If you're interested, this was inspired by the mechanism inside of a clicky pen, which converts repeated reciprocating motion to rotary in a similar way to what you are requesting - have a look at a transparent clicky pen and you'll see the mechanism spins as you click it!
There is another concept that proves it is mathematically possible without adding a flywheel type extra weight. While this contraption is not exactly ideal, with collisions on the walls at 90 degree angles, and not exactly 100% the same as a typical crank, but does imply it is mathematical possible.So, since it isn't actually a flywheel, beyond having a rotational component, like many other bits and pieces of the system like the crankshaft, crankarm, piston-rod, etc...
Without rotational momentum, a basic system (piston->piston-rod->crank-arm->crankshaft) is never getting past tdc/bdc, regardless of how friction-free the bearings are.