Crankshaft, What it is and how it works.


Crankshaft, What it is and how it works.

A crankshaft is a rotating shaft which (in conjunction with the connecting rods) converts reciprocating motion of the pistons into rotational motion. … The crankshaft rotates within the engine block through use of main bearings, and the crankpins rotate within the connecting rods using rod bearings.


What causes the crankshaft to rotate?

Compression makes the fuel-air mix explode with greater force. Power cycle: spark from a spark plug ignites the fuel-air mix. The explosion forces the piston down the cylinder. … As the pistons are forced up and down they rotate the crankshaft, which after sending the power through the transmission, turns wheels.


Is there a difference between camshaft and crankshaft?

A camshaft uses egg-shaped “cams” to open and close engine valves (one cam per valve), while a crankshaft converts “cranks” (the up/down motion of the pistons) to rotational motion.


A crankshaft is a fundamental feature in a vehicle’s engine. It is the system that converts linear energy into rotational energy. This enables the wheels to drive the car forward. All the pistons in the engine are attached to the crank which is also connected to the flywheel. The crank works in association with other engine components to achieve a synchronized motion.


Cylinder Arrangement

The crankshaft is found below the cylinders of a vehicle’s engine. On V-type engines it is found at the base but on flat engines it is found between the cylinder banks. Motor vehicles may have three to 12 cylinders inside the engine although most have four. Inside each cylinder is a piston which moves up and down the cylinder. All the engine’s pistons are connected to the crankshaft by individual rods. The cylinders work in concert as well as with other engine parts. This is referred to as the four-stroke cycle and occurs in each of the four cylinders. This cycle is what drives a vehicle’s engine.

Four-Stroke Cycle


The four strokes refer to intake, compression, power, and exhaust. On the intake stroke, the piston starts down as the intake valve opens to allow air and fuel into the cylinder. As soon as the piston arrives at the base of the intake stroke, it triggers closure of the intake valve. The air-fuel mixture is retained in the cylinder. This mixture is compressed severely by the piston as it moves up. The cylinder contents are ignited by the spark plug during which process expansion occurs. The combustion process lowers the piston which turns the crank to yield power to drive the vehicle. The exhaust valve then opens to release the exhaust once the piston gets to the bottom of the cylinder. The piston then returns to top of cylinder expressing burned gases through exhaust valve. The 4 stroke cycle then repeats.

Crankshaft-Camshaft Operations

The crank moves the pistons up and down inside the cylinders. The movement of the pistons is regulated by the crank. A component known as the camshaft also ensures that the pistons work properly. Whenever the crank rotates, the camshaft must also rotate along with it. This is because the two components are linked together. The two engine parts have a synchronized movement. When the camshaft rotates it causes the intake and exhaust valves to open and close. This allows a flow of air which is important to cause explosions in the cylinder. Explosions are created inside the cylinders in the engine. The explosions exert pressure on the pistons so that they maintain their movement. These explosions result in movement of the wheels. The moving pistons give rise to jerky movements. The flywheel which is found at the end of the shaft helps to ease the erratic movement. When the shaft moves, it causes the flywheel to adopt a circular motion. Notches in the flywheel help it to achieve a more regular motion. This motion eventually causes the vehicle’s wheels to turn since the flywheel is connected to other vehicle parts.


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