What is the purpose of the crankshaft in an engine?

• A. To ignite the air-fuel mixture
• B. To convert linear motion into rotational motion
• C. To control valve timing
• D. To facilitate air intake

Answer: (B)

The crankshaft plays a crucial role in an engine's operation by converting the linear motion of the pistons into rotational motion. When the air-fuel mixture inside the combustion chamber ignites, it generates a force that pushes the piston down. This linear movement of the pistons is then transmitted to the crankshaft, which is designed to rotate around its axis. The rotational motion produced by the crankshaft is what ultimately powers the vehicle, as it connects to other components such as the transmission and drives the wheels. Understanding this fundamental function of the crankshaft is essential for comprehending how an engine transforms fuel energy into mechanical energy for vehicle propulsion.