For the forty years following the
of the Wright brothers, airplanes used
internal combustion engines
Today, most general aviation or private airplanes are still
powered by propellers and internal combustion engines, much like your
We will discuss the fundamentals of the
internal combustion engine using the
Wright brothers' 1903 engine, shown in the figure, as an example.
The brothers' design is very simple by today's standards, so it is a good
engine for students to study and learn the
fundamentals of engines
On this page we present a
computer drawing of the lubrication system of the Wright
brothers' 1903 aircraft engine.
The figure at the top shows the major components of the lubrication system
on the Wright 1903 engine.
In any internal combustion engine,
fuel and oxygen are combined in a
to produce the power to turn the
crankshaft of the engine.
The combustion generates high pressure exhaust gas
which exerts a force on the face of a
The piston moves inside a cylinder and is connected to the crankshaft
by a rod which transmits the power.
There are many moving parts is this power train as shown in this computer
The job of the lubrication system is to distribute oil to the
moving parts to reduce friction between surfaces which rub against
The lubrication system used by the Wright brothers is quite simple.
An oil pump is located on the bottom of the engine, at the left
of the figure. The pump is driven by a worm gear off the main exhaust
valve cam shaft. The oil is pumped to the top of the engine, at the right,
inside a feed line. Small holes in the feed line allow the oil to
drip inside the
crankcase. In the figure, we have removed the
and peeled back the covering of the crankcase to see inside. The oil drips
onto the pistons as they move in the cylinders, lubricating the surface
between the piston and cylinder. The oil then runs down inside the crankcase
to the main bearings holding the crankshaft. Oil is picked up and splashed
onto the bearings to lubricate these surfaces. Along the outside of the bottom of the
crankcase is a collection tube which gathers up the used oil
and returns it to the oil pump to be circulated again.
Notice that the brothers did not lubricate the valves and rocker assembly
for the combustion chambers.
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