Basic Engine Parts
The core of the engine is the cylinder, with
the piston moving up and down inside the cylinder. The engine described above
has one cylinder. That is typical of most lawn mowers, but most cars have more than one cylinder (four, six and eight cylinders are
common). In a multi-cylinder engine, the cylinders usually are arranged in one
of three ways: inline, V or flat (also known as horizontally opposed or boxer), as shown in the
following figures.
Different configurations have different
advantages and disadvantages in terms of smoothness, manufacturing cost and
shape characteristics.
These advantages and
disadvantages make them more suitable for certain vehicles.
Let's
look at some key engine parts in more detail.
Spark
plug
The spark plug supplies the spark that ignites the air/fuel mixture so
that combustion can occur. The spark must happen at just the right moment for
things to work properly.
Valves
The intake and exhaust valves open at the proper time to let in
air and fuel and to let out exhaust. Note that both valves are closed during
compression and combustion so that the combustion chamber is sealed.
Piston
A piston is a cylindrical piece of metal that moves up and down
inside the cylinder.
Piston
rings
Piston rings provide a sliding seal between the outer edge of
the piston and the inner edge of the cylinder. The rings serve two purposes:
·
They prevent the fuel/air mixture and exhaust in the combustion
chamber from leaking into the sump during compression and combustion.
·
They keep oil in the sump from leaking into the
combustion area, where it would be burned and lost.
Most
cars that "burn oil" and have to have a quart added every 1,000 miles
are burning it because the engine is old and the rings no longer seal things
properly.
Connecting
rod
The connecting rod connects the piston to the crankshaft. It can
rotate at both ends so that its angle can change as the piston moves and the
crankshaft rotates.
Crankshaft
The crankshaft turns the piston's up and down motion into
circular motion just like a crank on a jack-in-the-box does.
Sump
The sump surrounds the crankshaft. It contains some amount of
oil, which collects in the bottom of the sump (the oil
Figure 2. Inline - The cylinders are arranged in a line in a single bank.
Figure 3. V - The cylinders are arranged in two banks set at an angle to one another.
Figure 4. Flat - The cylinders are arranged in two banks on opposite sides of the engine.
.
No comments:
Post a Comment