What is the purpose of the crankshaft?

The purpose of the crankshaft is to convert the linear motion of the pistons into rotational motion. In an internal combustion engine, the pistons move up and down in response to the combustion process. As the pistons move downward, they push against the connecting rods, which are attached to the crankshaft. This interaction transforms the linear motion generated by the pistons into a rotary motion that is necessary for the engine to turn the wheels of the vehicle.

This transformation is crucial for vehicle operation, as it is this rotational motion of the crankshaft that ultimately drives the drivetrain, allowing the vehicle to move. Without the crankshaft performing this key function, the energy produced by the pistons through combustion would not be effectively harnessed to provide propulsion.

The other options refer to different components and functions within an engine and drivetrain system, such as power transmission, valve timing, and engine starting mechanisms, none of which relate directly to the primary function of the crankshaft.