Crankshaft
Combustion of the fuel-air mixture in the engine produces power. This power is transformed into rotary movement of the crankshaft.
Function
Combustion of the fuel-air mixture in the engine produces power. This power is transformed into rotary movement of the crankshaft. The linear motion of the pistons is converted by way of the connecting rod into a 
torque and is then passed to the flywheel.
The crankshaft has to withstand considerable loads in this process. On the one hand it is subjected to severe bending and torsional stress. Further loads arise from torsional vibration, as the rotary movement of the crankshaft is constantly being abruptly accelerated and decelerated. The bearings are also subject to a high degree of wear.
Crankshaft design and components
To be able to withstand wear and the strain of rotary movement, crankshafts need to have a hard surface and a tough core. For this reason crankshafts are often forged. Alloyed heat-treated steel or nitrided steel is used as raw material. The crankshaft journals are also surface-hardened. A crankshaft comprises the following components:
- Main journals
- Crank pins
- Crank webs
- Counterweights
