1. Crankshaft and Oil Film Journal Bearing
Presenter: Aaron Ma
Date: Nov 8, 05
Objective: To explain the role and function of the crankshaft and the bearing in an engine.

2. Purpose of Crankshaft
Converts the piston's linear up and down motion into circular rotating motion.
Connected to the piston by a connecting rod

3. How is a Crankshaft Made?
Forged or cast from either mild steel or high strength steel
Machined out of a single billet of forged steel
Cost mild<cast<forged/billet

4. Why are so many of its dimensions critical?
determines the piston stroke measurement, and engine displacement;
Ex. a common way to increase the power of an engine is to increase the stroke.
increases the reciprocating vibration, however, limiting the high RPM capability of the engine

5. Oil Film Bearings
Carries load by sliding
Sealed around the crankshaft

6. How is the oil supplied to the film bearings?
Crankshaft rotates
Bearing is dipped into oil sump under crankshaft
Fluid is swept into the bearing, forming a lubricating wedge under or around the shaft.
Rely on an external pump to supply fluid

7. References http://en.wikipedia.org/wiki/Crankshaft