Complete assembly design for a one cylinder engine. Just the rotor (crankshaft) and cilinder assembly. No gears for oil supply or spark timing devices.
Detail. Crankshaft to piston shaft connection. Needle bearing insert and small oiler openings to piston crankshaft bearing setting. This connection axl is static as depicted by the squared axl insert side.
Just a detail rendering. Slotted connection to crankshaft.