Дизельные двигатели. Эксплуатация и обслуживание = Diesel engines. Operation and maintenance. Практикум
.pdf2.STRUCTURAL PARTS OF A DIESEL ENGINE
1.Read and translate the text. Pay attention to new phrases.
Structural Parts of a Diesel Engine
The principle components of an internal combustion engine may be divided into two principle groups — parts and systems. The main parts of an internal combustion engine may be divided into structural parts and moving parts. The frame of the modern diesel may include such parts as the cylinder block, crankcase, bedplate or base, sump or oil pan, and end plates. The engine frame part which supports the engine's cylinder liners and cylinder heads is called the cylinder block. The engine frame part, which serves as a housing for the crankshaft, is called the crankcase.
In large engines of early design, the support for the main bearings was provided by a bedplate. In some large engines the support for main bearings is provided by a part called the base.
Since lubrication is essential for proper engine operation, a reservoir for collecting and holding the engine's lubricating oil is a necessary part of the engine structure. The reservoir may be called a sump or an oil pan, depending upon its design, and is usually attached directly to the engine. However, in some engines, the oil reservoir may be located at some point relatively remote from the engine; such engines may be called dry sump engines.
Some engines have flat steel plates attached to each end of the cylinder block. End plates add rigidity to the block and provide a surface to which may be bolted housings for such parts as gears, blowers, pumps and generators.
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Many engines, especially the larger ones, have access openings in some parts of the engine frame. These openings permit access to the cylinder liners, main and connecting rod bearings, injector control shafts and various other internal engine parts. Access doors (sometimes called covers or plates) for the openings are usually secured with handwheel or nut-operated clamps and are fitted with gaskets to keep dirt and foreign material out of the engine's interior.
The cylinder assembly consists of the head, the liner, the studs and the gasket; it provides a gas and liquid-tight space. Practically all diesel engines are constructed with replaceable cylinder liners. The liners or bores must be sealed tightly to form the combustion chambers. The space at the combustion end of a cylinder is formed and sealed by a cylinder head, which is a separate unit from the block.
A number of engine parts, which are essential to engine operation, may be found in or attached to the cylinder head. The cylinder head may house intake and exhaust valves, valve guides and valve seats, Rocker arm assemblies are frequently attached to the cylinder head.
The fuel injection valve is almost always in the cylinder head. Cylinder heads of a diesel engine may also be fitted with air starting valves, indicator and blow down valves, and safety valves. Large diesel engines generally have one-cylinder head for each cylinder.
In most cases, the seal between the cylinder head and the block depends principally upon the studs and gaskets. The studs, or stud bolts, secure the cylinder head to the cylinder block. A gasket between the head and the block is compressed to form a seal when the head is properly tightened down.
structural parts
moving parts
frame
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cylinder block
crankcase
bedplate
oil sump
oil pan
support for main bearings
proper engine operation
reservoir for collecting and holding the engine's lubricating oil
dry sump engine
add rigidity to the block
provide a surface
gear
blower
pump
access openings
cylinder liner
connecting rod bearings
injector control shafts
handwheel
nut-operated clamps
be fitted with gaskets
cylinder assembly
stud
provide a gas and liquid-tight space
seal tightly
attach to the cylinder head
form the combustion chamber
intake valve
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exhaust valve
valve guides
safety valve
rocker arm
fuel injection valve
air starting valve
blow down valve
secure the cylinder head to the cylinder block
tighten down properly
2. Complete the sentences choosing the proper word:
1.The components of an internal combustion engine are … .
2.The main parts are divided into … .
3.The frame of a modern diesel includes such parts as … .
4.The engine frame part which supports cylinder liners and cylinder heads the housing for the crankshaft is called … .
5.The essential part for collecting and holding the engine’s lubricating oil is called … .
6.The cylinder assembly consists of … .
7.The cylinder heads house … .
8.The … valve is always in the cylinder head.
9.Cylinder heads of a diesel engine are fitted with … .
10.The cylinder head is secured to the cylinder block by … .
11.The support for main bearings is called … .
(base; studs; parts and systems; intake, exhaust valves, valve guides and valve seats; structural and moving parts; the cylinder block, crankcase, bedplate, sump, end plates; cylinder block; fuel injection valve; crankcase; the head, the liner, the studs and the gasket; reservoir or sump; air starting valves, indicator and blow down valves)
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3.MOVING PARTS OF A DIESEL ENGINE
1.Read and translate the text. Pay attention to new phrases.
Moving Parts of a Diesel Engine
The moving parts may be divided into three groups: the parts which have only reciprocating motion (pistons), the parts which have both reciprocating and rotating motion (connecting rods), and the parts which have only rotating motion (crankshafts and camshafts).
The piston and rod assemblies include a piston, piston rings, piston pin, connecting rod, and related bearings. The piston must be so designed and must be made of such materials that it can withstand the extreme heat and pressure of combustion. The piston aids in the sealing of the cylinder to prevent the escape of gas and transmits some of the heat to the cylinder wall. A piston serves as a valve in opening and closing the ports of a two-stroke cycle engine.
Piston rings perform three functions: seal the cylinder, distribute and control lubricating oil on the cylinder wall, and transfer heat from the piston to the cylinder wall. In trunk-type piston assemblies, the connection between the piston and the connecting rod is usually the piston pin.
The connecting link between the piston and crankshaft or the crankshaft and the crosshead of an engine is the connecting rod.
The camshaft is a shaft with eccentric projections, called cams, designed in control the operation of valves, usually through various intermediate parts. The cams are arranged on the shaft to provide the proper firing order of the cylinders. The shape of the cam determines the point of opening and closing, the speed of opening and closing, and the amount of the valve lift. All cylinders will be affected if there is
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a change in timing. The camshaft is driven by the crankshaft by various means; the most common are gears or a chain and sprocket.
One of the principle engines parts, which has only rotating motion, is the crankshaft. The crankshaft changes the movement of the piston and the connecting rod into the rotating motion required to drive such items as reduction gears, propeller shafts, generators, pumps, etc. The parts of a crankshaft are main bearing journals, connecting rod journals, counterweights, timing gear bolting flange, lubricating oil holes, and flywheel dowel. The flywheel is a means, which stabilizes shaft rotation.
An important group of engine parts consists of the bearings. Some bearings remain stationary in performing their function while others move. Main bearings which support the crankshaft are of the sliding contact, or plain type, consisting of two halves or shells. The bearings used in connection with the piston pins are of three types: the integral bearing, the sleeve bearing or bushing, and the needle type roller bearing. The bearings in the bosses (hubs) of most pistons are of the sleeve bushing type.
moving parts
reciprocating motion
rotating motion
piston
connecting rod
crankshaft
camshaft
piston and rod assembly
piston rings
piston pin
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withstand the extreme heat and pressure of combustion
aid in the sealing of the cylinder
prevent the escape of gas
transmit some of the heat to the cylinder wall
serve as a valve in opening and closing the ports
seal the cylinder
distribute and control lubricating oil on the cylinder wall
transfer heat from the piston to the cylinder wall
shaft with eccentric projections
cam
provide the proper firing order of the cylinders
determine the point of opening and closing
amount of the valve lift
timing
chain and sprocket
change the movement of the piston and the connecting rod into the rotating motion
reduction gear
propeller shaft
main bearing journal
connecting rod journal
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counterweight
timing gear bolting flange
lubricating oil hole
flywheel dowel
stabilize shaft rotation
bearing of the sliding contact
bearing of plain type
integral bearing
sleeve bearing or bushing
needle type roller bearing
boss
hub
2. Complete the following sentences choosing the proper word:
1.Parts of the engine which have only reciprocating motion are … .
2.Parts of the engine which have both reciprocating and rotating motion are … .
3.Parts which have only rotating motion are … .
4.The piston and rod assemblies include … .
5.The function of the piston rings are the following … .
6.The connection between the piston and connecting rod in the trunk-type piston is … .
7.The connection between the piston and crankshaft or the crankshaft and the crosshead is … .
8.The camshaft is a shaft with cams which provide … in the cylinder.
9.The parts of the crankshaft are … .
10.A means which stabilizes shaft rotation is … type comprise an important group of engine parts.
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(sleeve, needle, roller bearings; pistons; crankshaft and camshaft; connecting rods; flywheel; a piston, piston rings, pin, connecting rod bearings; main bearing journals, counterweight, lubricating oil holes, flywheel dowel, timing gear bolting flange; seal the cylinder, distribute and control lubricating oil, transfer heat to the cylinder wall; firing order of the cylinder; piston pin; connecting rod)
3. Put the verb in the correct form of the Passive Voice:
1.The piston (to make) of such materials that it can withstand the extreme heat and pressure of combustion.
2.The lubricating oil (to distribute) on the cylinder wall 2 minutes
ago.
3.The proper firing order of the cylinders (to provide) due to arranging the cams on the shaft.
4.The camshaft (to drive) by the crankshaft by various means; the most common are gears and chain. Shaft rotation (to stabilize) by the flywheel.
5.Sleeve, needle, roller types of bearings (to use) in the piston.
4. Put questions to the underlined words:
1.Pistons have only reciprocating motion.
2.Piston rings transfer heat from the piston to the cylinder wall.
3.The flywheel stabilizes shaft rotation.
4.The bearings in the bosses of most pistons are of the sleeve bushing type.
5.The piston and rod assemblies include a piston, piston rings, piston pin, connecting rod and bearings.
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5. Translate from Russian into English:
1.Поршневой палец — это соединение между поршнем и шатуном.
2.Поршень способствует уплотнению цилиндра, чтобы предотвратить просачивание газа, и передает часть тепла к стенке цилиндра.
3.Коленчатый вал приводит в движение редукторы, гребной вал, генераторы.
4.Как называется соединение между коленчатым валом и крейцкопфом?
5.Поршень служит в качестве клапана при открытии и закрытии окон в двухтактном двигателе.
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