Automobile Aircraft Diesel #228284

The connecting rod is a straight rod with one end fastened to a pin or pivot in the piston so the lower end can swing. The crank shaft is a shaft with its ends mounted in oiled bear ings so it can revolve, and thus the offset portion in the middle, the crank, describes a circle as the shaft turns around. The lower end of the connecting rod is fastened to the crank, so it must follow the same circular path.