Engine Power Train
This is a computer animation of the power train of the Wright
1903 aircraft engine.
This engine powered the first, heavier than
air, self-propelled, maneuverable, piloted aircraft; the Wright
flown at Kitty Hawk, North Carolina, in December, 1903.
for their aircraft, the brothers used twin, counter-rotating
at the rear of the aircraft. To turn the propellers, the
brothers designed and built a
internal combustion engine.
In this animation, and on the figure below,
we have stripped away all of the
except those associated with the power train.
The view is from above the rear of the engine.
As the name implies, the job of the power train is to provide the power
to turn the aircraft propellers.
For the brothers' propulsion system, two power sprockets are
located on a rotating crankshaft, colored red, which turns
large "bicycle" chains to power the propellers.
The energy to rotate the crankshaft is provided during the
of four pistons, colored gray, moving in enclosed cylinders, colored blue.
The power train converts the linear motion of the pistons
into rotational motion of the crankshaft.
There are three main parts to the power train; the crankshaft,
the pistons, and the cylinders.
The crankshaft is a single, long piece of metal which
is cut into a very specific "snake" shape. The ends of the shaft are rounded
to accept the flywheel and the sprockets at the right of the figure, and the
timing sprocket on the left end.
The three rounded sections in the middle of the crankshaft ride on bearings in the
crankcase of the engine.
There are four additional rounded sections of the crankshaft which are enclosed
by the ends of the piston rods.
The piston rods are connected to the pistons by pins which you can't see
in this view.
are connected to the opened ends of the cylinders, to the
left in the figure. During the
of the fuel, the pressure is increased in the combustion chamber and in the volume formed
by the piston head and the top of the cylinder. The pressure on the head of the cylinder
generates the force to move the piston and the crankshaft. The pistons fire one at a
time in a
The job of the flywheel is to store the energy from the individual firings so that
the engine runs more smoothly.
- Re-Living the Wright Way
- Beginner's Guide to Aeronautics
- NASA Home Page