6D34 Used Camshaft For Excavator SK200 - 3 SK230 - 6E ME081737
Specification
| Engine Type: Diesel | Type: Diesel Engine |
| Application: Engineering Machinery Engine | Number of cylinders: 6 |
| Teeth quantity: 62 | Size: Standard |
| Type: Direct injection | Item name: Engine Camshaft |
Description
How Camshafts Work
The camshaft uses lobes (called cams) that push against the valves
to open them as the camshaft rotates; springs on the valves return
them to their closed position. This is a critical job, and can have
a great impact on an engine's performance at different speeds.
Camshaft Basics
The key parts of any camshaft are the lobes. As the camshaft spins,
the lobes open and close the intake and exhaust valves in time with
the motion of the piston. It turns out that there is a direct
relationship between the shape of the cam lobes and the way the
engine performs in different speed ranges.
To understand why this is the case, imagine that we are running an
engine extremely slowly -- at just 10 or 20 revolutions per minute
(RPM) -- so that it takes the piston a couple of seconds to
complete a cycle. It would be impossible to actually run a normal
engine this slowly, but let's imagine that we could. At this slow
speed, we would want cam lobes shaped so that:
Just as the piston starts moving downward in the intake stroke, the
intake valve would open. The intake valve would close right as the
piston bottoms out.
The exhaust valve would open right as the piston bottoms out at the
end of the combustion stroke, and would close as the piston
completes the exhaust stroke.
This setup would work really well for the engine as long as it ran
at this very slow speed. But what happens if you increase the RPM?
Let's find out.
When you increase the RPM, the 10 to 20 RPM configuration for the
camshaft does not work well. If the engine is running at 4,000 RPM,
the valves are opening and closing 2,000 times every minute, or 33
times every second. At these speeds, the piston is moving very
quickly, so the air/fuel mixture rushing into the cylinder is
moving very quickly as well.
