What is the main function of a crankshaft in an engine?

A crankshaft is a vital component in an internal combustion engine that primarily serves to convert the linear motion of the pistons into rotational motion. As the pistons move up and down during the combustion process, they push on the connecting rods that are attached to the crankshaft. This action causes the crankshaft to rotate, which ultimately drives the engine's output, powering the vehicle.

The design of the crankshaft, with its offset pins, allows it to translate this linear movement into the necessary rotational force needed to turn the wheels of the vehicle or drive other components. This conversion is essential for the functioning of an engine, as it transforms the energy produced by fuel combustion into mechanical power.

The other options, while closely related to motion, do not accurately represent the primary role of the crankshaft in the overall engine function.