Entec EW-4200D Gebruiksaanwijzing - Pagina 18

Blader online of download pdf Gebruiksaanwijzing voor {categorie_naam} Entec EW-4200D. Entec EW-4200D 19 pagina's. Marine diesel generators

Pagina afdrukken

Theory of Operation

HOW COMPRESSION IGNITION WORKS

In a four cycle engine, four strokes of the piston are required to

complete one cycle; Intake, Compression, Power, and Exhaust.

With only one stroke providing power, a heavy rotating flywheel

keeps the crankshaft turning through the other three strokes.

Intake Stroke. When the intake valve (8/4) is open and the

piston (7/15) is pulled downward in the cylinder (7/27), air is

drawn into the cylinder and fills the volume above the piston

(intake stroke).

Compression. At the bottom of the stroke, the intake valve

closes and the piston is pushed up toward the cylinder head. The

trapped air is compressed into a small volume (the cup in the top

of the piston) and heat is generated due to this compression. The

smaller the volume the more heat is generated. When the heat in

the compressed air can be concentrated in the piston cup so that

it cannot escape into the cylinder walls, etc., the temperature of

the compressed air will get very high.

Power Stroke. At the top of the compression stroke the fuel is

sprayed into the very hot compressed air and ignites. As the fuel

burns, the hot combusted gases expand, forcing the piston down.

The force applied to the top of the piston in the downward

motion is converted into rotary motion by the connecting rod

and the crankshaft. This is called the power stroke.

Exhaust Stroke. At the bottom of the power stroke, the exhaust

valve (8/11) is opened and as the piston comes back up, the

burned gases are expelled into the exhaust elbow (16/6). When

the piston is back at the top, the exhaust valve closes, the intake

valve opens, and the whole cycle is repeated. This is called a

four cycle engine.

Piston Cup Design. The unique

"cup" design in the top of the

piston helps to contain the "heat

of compression," and is what

gives our engine the ability to

start without the aid of glow

plugs and/or heaters. It also

makes it possible to start the

engine with a handcrank.

Piston Cup

16710 SW 72nd • Portland, Oregon 97224 • (503) 624-7118

EW-4200D

Intake

Compression

Power

Exhaust

Entec West, Inc.