Stirling Engine

The stirling engine is a type of external combustion engine. Invented in 1816 by a Scottish clergyman, Robert Stirling, it is now receiving serious consideration as an alternative to the internal combustion reciprocating engine, because the Stirling emits virtually forming hydrocarbons. The stirling engine satisfies U.S. standards for emission of nitrogen oxides and is also significantly queter than conventional gasoline and diesel engines. Single and multicylinder models are made.

A single cylinder stirling engine has five major components; an engine heater, a regenerator, an engine cooler, a displacer piston, and a power piston. The heater is a bank of stainless steel tube brazed into the cylinder head and regenerator. These tubes are  kept hot by burning fuel in an external combustion chamber. The regenerator is a mass of wire sealed within several cups located around the outside of the engine. The cooler consist of boundles of small tubes surrounded by an annular chamber through which cooling water is circulated. The displacer piston is a hollow steel shell that fits loosely in the cylinder. The motion of the displacer piston rod connecting it to the drive mechanism in the crankcase.