Prime Mover

A device that continuosly transform thermal, electric, hydraulic and other types of energy into power is called a prime mover. They are also calles heat engines, that's the reason why they are Thermal machines, and they are divided in two categories:

1. External combustion engines are the ones that generate power indirectly through the heat produced from the combustion of the fuel, some examples of these engines are the steam engines and the steam turbines.
2. Internal combustion engines are the ones that generate power directly from the gas that they produce, like gas engine, gasoline engine and diesel engine.



 
This is an image of a big steam engine that operated machinery in the Machine Hall of the Philadelphia International EXPO of 1876, in the same room there was eshibited the gas engine.