Each engine part has its own particular function to perform and in conjunction with other parts, equally as important, comprises the assembly called the internal-combustion engine or, for short, combustion engine.
An understanding of the operation or functions of the individual parts is necessary for a better understanding of the whole engine.
A person who intends to work in the diesel-engine field must know how to recognize the engine parts by sight and must learn their correct names and also their particular functions.
In Figs. A-1and A-2 are shown cross-sectional views of a diesel engine of the heavier type. In Fig. A-1 the section of the cylinder head is taken through the injector, or spray nozzle, and starting-air valve, whereas Fig. A-2 is a section one vertical plane through the center line of the engine and in the cylinder head shows the intake and exhaust valves.
In Fig. A-3 is shown the cross section of a diesel engine that is used in the automotive transportation field. Attention is called to the difference in the general construction of these two types of engines.
The following glossary of terms gives the student a preliminary understanding of the component parts used in the diesel engine and their functions as well as an explanation of some basic units and definitions of a more theoretical nature but indispensable to a person who wants to work intelligently in the chosen field and to rise from apprentice to engine operator and possibly to chief engineer of a large plant.
The way to use the drawings and the glossary is to study the drawings and to look up in the glossary every part name for explanation.
However, even a man familiar with diesel engines should have some use for the glossary looking up terms, units, and occasionally a definition to make sure that he remembers them correctly. Knowledge confirmed by an authoritative source is the best knowledge a person may have.