What is the primary role of the crankshaft in an engine?

The primary role of the crankshaft in an engine is to convert the linear motion of the pistons into rotational motion. As the engine runs, the pistons move up and down in their respective cylinders due to the combustion of fuel and air. This linear motion needs to be transformed into rotational motion to turn the vehicle's wheels and ultimately to power various systems in the vehicle. The crankshaft accomplishes this conversion by connecting to the pistons via connecting rods; as the pistons move down, they push the connecting rods, which in turn rotate the crankshaft. This rotational motion is then utilized to drive the transmission and ultimately propel the vehicle.

Other functions within the engine include managing air intake, circulating oil, and timing fuel injection, but these are distinct from the specific task the crankshaft is designed for, which is fundamental to the engine's operation and overall power delivery.