How a Diesel Engine Works

The Main Parts of a Diesel Engine

The main parts of a diesel engine are: the cylinder, the piston, the connecting rod, the crankshaft, valves or ports, the fuel pump and the nozzle.

In the cylinder the piston moves up and down and makes strokes. The piston is connected to a mechanism which controls its motion and is called a crank mechanism. The crank mechanism consists of a shaft which turns or revolves in bearings and has a crank which turns in a circle when the shaft revolves, and a connecting rod which connects the crank to the piston. Through the intake valves or ports air is delivered into the cylinder. A spray nozzle or a fuel injector delivers fuel oil. It is injected in the form of a finely divided spray by a pump which is called a fuel injection pump.

diesel engine д.в.с.

piston, n поршень

crank, n мотыль, кривошип

crankshaft, n коленчатый вал

crank mechanism кривошипный механизм

shaft, n вал

connect, v соединять

connecting rod шатун

fuel oil топливо

fuel pump топливный насос

intake valve впускной клапан

port, n окно

nozzle, n сопло

inject, v впрыскивать

injection, n впрыскивание, распыление

injector, n форсунка

stroke, n ход, такт /поршня/

move, v двигаться

motion, n движение

bearing, n подшипник

consist of, v состоять из

revolve, v вращать/ся/

rotate, v вращать/ся/

deliver, v подавать /топливо/

spray, n, v струя; разбрызгивать,

распылять

What Work the Parts of an Engine Perform

The heart of an engine is the cylinder where the fuel is burnt and the power is developed. The cylinder head closes the top end of the cylinder to make space where the air is compressed and the gases are confined while they are burning and expanding.

The piston moves up and down in a cylinder. It compresses the air charge. When the gases are burning and expanding the piston receives the pressure of the gases. The connecting rod transmits the motion of the piston to the crankshaft. The main bearings support the crankshaft and permit it to rotate. Valves or ports admit air and discharge the burnt or exhaust gases. The frame and the bedplate are used to hold the cylinder, the crankshaft and main bearings together.

The fuel injection pump is used to deliver fuel into the cylinder and the fuel injection nozzle is used to divide the fuel into a fine spray as it enters the cylinder.

perform выполнять charge заряд; заряжать, загружать discharge выпускать expand расширять/ся/ develop развивать, вырабатывать receive, get получать fuel injection pump топливный насос высокого давления spray распылять; струя as (зд.) когда compress сжимать

enter поступать в permit разрешать pressure давление cylinder head крышка цилиндра confine ограничивать transmit передавать support поддерживать exhaust gases отработавшие газы frame рама bedplate станина

How a Diesel Engine Works

In the engines of four-stroke cycle there are four working strokes occupying two complete revolutions of the crankshaft. These four strokes are:

The Intake Stroke. The piston is at the top of the cylinder (top dead centre - t.d.c.) being ready to take in a charge of air. The inlet valve is opened, the exhaust valve is closed. The crankshaft is turning. Turning to the right and down, the shaft pulls down the connecting rod and the rod pulls down the piston.

The piston goes down and takes in air into the cylinder through the intake valve. When the piston comes to the bottom of its stroke (bottom dead centre - b.d.c.), the intake valve closes. The cylinder is now full of fresh air.

The Compression Stroke. During this stroke the crankshaft is turning to the left and upward. And the connecting rod pushes the piston upward. The piston moves upward compressing the air charge. Since all valves are closed, the air doesn't escape. The air charge is forced into a smaller space. This increases the pressure of the air and its temperature. When the piston comes to the top center, the air occupies only 1/16 of its original space and its temperature rises to 1,000°F.

The Power Stroke. Now fuel oil is sprayed through the fuel injector into the hot compressed air. The air is so hot that it automatically ignites the oil. The oil burns producing more heat and pressure. This pressure pushes the piston down on the power stroke. The piston goes down. The motion of the piston is transmitted by the connecting rod to the crank. The force on the crank makes the crankshaft turn. Before the piston comes to the bottom center, the exhaust valve is opened. The burnt gases begin to escape through the exhaust valve. This is the end of the power stroke.

The Exhaust Stroke. The cylinder is still full of burnt gases. When the piston rises it pushes out the remaining gases through the exhaust valve. When the piston is at the top center all the burnt gases are exhausted from the cylinder. The exhaust stroke is completed and the engine is ready to begin another cycle.

top dead centre (t.d.c.) верхнее крайнее положение

(верхняя мертвая точка)

bottom dead centre (b.d.c.) нижнее крайнее положение

(нижняя мертвая точка)

working stroke рабочий ход

intake stroke такт впуска

compression stroke такт сжатия

power stroke такт горения-расширения

(рабочий такт, ход)

exhaust stroke такт выпуска

occupy, v занимать

charge, n, v заряд; заряжать

revolution, n оборот

pull, v тянуть, тащить

down = downward, prep вниз

up = upward, prep вверх

reach, v достигать

space, n пространство

rise (rose, risen), v поднимать(ся)

complete, v, adj завершать, (зд.) полный

make, v (зд.) заставлять

heat, n, v тепло; нагревать

remain, v оставаться

increase, v увеличивать

original, adj первоначальный

ignite, v зажигать(ся)

produce, v производить

force, n сила; нагнетать

draw in (drew, drawn), v всасывать

push, v толкать

oil, n (зд.) топливо

still (зд.) все еще

Дата добавления: 2015-10-30