| How Stirling Engines Work
Stirling engines can be hard to understand. Here are the
key points. Every Stirling engine has a sealed cylinder with one part hot
and the other cold. The working gas inside the engine (which is often air,
helium, or hydrogen) is moved by a mechanism from the hot side to the cold
side. When the gas is on the hot side it expands and pushes up on a piston. |
When it moves back to the cold
side it contracts. Properly designed Stirling engines have two power pulses
per revolution, which can make them very smooth running.
Two of the more common types are two
piston Stirling engines and displacer-type
Stirling engines. The two piston type Stirling engine has two power pistons.
The displacer type Stirling engine has one power piston and a displacer
piston. |
The
displacer type Stirling engine is shown here. The space below the displacer
piston is continously warmed by a heat source. The space above the displacer
piston is continously cooled. The displacer piston moves the air (displaces
the air) from the hot side to the cold side. The 
The
two piston type Stirling engine is shown here. The space above the hot
piston is continuously warmed by a heat source. The space above the cold
piston is continuously cooled.