Features/Functions:

Advantages: The cylinders’ centerline is in the same plane, and the crankshaft pin is only connected with the large end of the main connecting rod, so this structure is compact and short in axial dimensions, which increases the crankshaft stiffness.

Disadvantages: There displacements of the two cylinders are different, and the additional bending moments caused by auxiliary connecting rod acts on the main connecting rod.

Connecting the crankshaft and piston, transmitting the force from the piston to the crankshaft.