An engine is an energy conversion device. Its core function is to convert other forms of energy into mechanical energy. Specifically:
Energy conversion process: Chemical energy is converted into thermal energy through the combustion of liquid or gaseous fuel; this thermal energy drives the reciprocating motion of a piston; a crank-connecting rod mechanism then converts the piston's linear motion into the rotational motion of the crankshaft, ultimately outputting mechanical energy.
Applicable energy types: In addition to the chemical energy of fuel, some engines can also directly convert electrical energy into mechanical energy to meet power requirements in various scenarios.
