45-1

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7)What is a blocking device equipped with?

8)How does opening of the valve perform?

9)What is the valve closed by?

10)What are the tappets or the rocker arms equipped with?

13. Put general questions to the sentences.

1.The valve timing gear comprises the following components: camshaft, tappets, and valves.

2.The tappets and the valve push rods are not required.

3.The port control is based on the opening and closing of ports in the cylinder wall.

4.Main component of the valve timing gear is the valve.

5.The valve is closed by the valve spring.

6.The actuating mechanism of the valve timing gear must have a clearance.

7.The valve mechanism is operating with a minimum of components.

14.Which words belong to the valve timing gear:

push rod, ports, camshaft, rate, cylinder, tappets, springs, crankcase, valve cone.

15.Write out the sentences with adverbs.

16.Make a plan of the text.

17.Write out all the key words.

18.Compose a short summary of the text using the following phrases:

The text gives a detailed account of ... .

The text deals with ... .

Much attention is paid to ... .

The text carries the information about ... .

In conclusion it should be noted that ... .

Unit VII

Power train clutch

The internal-combustion engine is not a self-starting type. If has to be started and only after its speed has been increased it develops a sufficient torque. For putting the vehicle in motion, all internal-combustion engine require some disengage able

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connection between engine and axle drive. This disengage able connection is designed as a friction clutch.

The disk clutches are built as multiple-disk and single-disk clutches. A difference is made between dry clutches and oil-batch clutches.

The motorcar clutch is required to engage smoothly and to transmit full engine torque without any slippage when completely engaged. Since the clutch is footoperated, the (pedal force) required for its disengagement should be as possible. Coupling is performed by friction, i.e., the friction surfaces of disks alternately connected with the engine and the change-speed gear to be driven are forced together by spring pressure.

They have been replaced by the single-disk clutch after wear-resistant clutch linings with high friction values had been developed. In modern automotive engineering it is used almost exclusively.

Nearly the whole diameter of the flywheel is employed for its housing resulting in maximum friction surface area. It has only one clutch disk whose hub rests in the splines of the gear shaft, and it is forced between the clutch pressure plate and the flywheel by the spring-loaded pressure plate. The elastic force is acting concentrically.

Six pressure springs are located at the circumference of the clutch in height of the clutch bolt. The springs are supported by a spring cage toward the outside and by the clutch pressure plate toward the inside, and they push the clutch disk against the flywheel.

Disengagement of the clutch is performed by slip ring connected with the clutch pedal via the throttle lever; in some models, this slip ring corresponds to a thrust ball bearing. This slip ring made of hard graphite pushes against the pressure ring when the clutch is disengaged. The three clutch levers actuated by the pressure ring are lifting the clutch pressure plate from the clutch disk by the adjusting screw. As a result the contact pressure of the clutch spring has no effect on the Clutch disk and the flow of power from the flywheel to the clutch shaft is interrupted.

Since only two friction surfaces have to be separated in this case, the space of separating amounts to 2 or 3 mm. The pedal path is approx. 100 mm so that the reduction ratio is high and the exertion required by the driver is little.

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In lorries (trucks) and buses equipped with air brakes, the clutch is sometimes operated by compressed air, i.e. not directly. Recently, the use of hydraulic clutches, has gained ground.

Instead of the mechanical friction clutches, automotive engineering uses fluid flywheel clutches (automatic transmission). The clutch housing is filled with oil. When driven by the engine and beginning with a certain speed, the oil in the primary wheel is pushed toward the outside by the centrifugal force and receives a rotary motion. As a result, the vanes of the secondary wheel are dragged along. Due to the low energy of flow of the oil when idling, no dragging is occurring. The more the speed is increased, the higher will be the dragging force acting on the secondary wheel. Thus, this type of clutch result is smooth starting, and it works nearly without any slippage in the higher speed range.

While reading the text pay attention to Glossary

GLOSSARY

power train – силовая передача, трансмиссия clutch – сцепление

internal combustion engine – двигатель внутреннего сгорания torque – крутящий момент

disengageable connection – разъемное соединение axle drive – осевой привод

friction clutch – фрикционное сцепление

oil-bath clutch – сцепление, работающее в масляной ванне slippage – проскальзывание, буксование

coupling – сцепление (синоним clutch) change-speed dear – коробка передач clutch gear – механизм сцепления

single-disk clutch – однодисковое сцепление multiplate – многодисковое сцепление lining – накладка

hub – ступица, втулка spline – шлиц, паз

gear shaft – вал зубчатой передачи

cage – корпус, кожух (синоним housing) slip ring – выжимное кольцо сцепления

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vane – лопасть

drag – задержка движения, торможение, прихватывание дисков сцепления, сопротивление в сцепление

throttle lever – рычаг управления, пусковой рычаг

Tasks

1.Find in the text English equivalents to the words and word combinations given below:

самоуправляемый, скорость, движение, двигатель, дисковые сцепления, сухие диски сцепления, работать ногой, сила педали, поверхности трения, максимальная площадь трения, давление пружины, маховик, диаметр, кожух, пластина, упругий (эластичный), высота, болт, кольцо, графит, поднимать, контактное давление, мощность (энергия), педаль, тормоза, сжатый воздух.

2.Find in the text the sentences telling you about:

a)How blow the engine has to be started.

b)How the coupling is performed.

c)Location of six pressure springs.

d)Disengagement of the clutch.

e)The pedal path.

f)Automatic transmission.

g)The dragging force.

Translate these sentences.

3. Find in the text the opposites to the following words and word expressions

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4. Match the following attributes and nouns. Select nouns that work as

5.Comment on grammar patterns in the text.

6.Find in the text Passive verb forms.

7.Find the answers to the following questions:

1)Is the internal - combustion engine a self - starting type?

2)What do all internal - combustion engines require?

3)Is the clutch necessary in a motorcar?

4)Do you know how clutch works?

5)Is there clutch pedal in the driver’s compartment?

6)Do you know what the clutch consists of?

7)How is coupling (the mechanism of clutch) performed?

8)Where does clutch disk hub rest?

9)How is the electric force acting?

10)Where are six pressure springs located?

11)What are the springs supported by?

12)What lifts the clutch pressure?

13)What is the pedal path like?

14)What brakes are lorries equipped with?

8. Correct the statements which are wrong (Use «false» or «true»).

1)The internal - combustion engine is a self - staring type.

2)For putting the vehicle in motion, all the internal - combustion engine requires some disengageable connection between engine and axel drive.

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3)The clutch in the hand - operated.

4)Coupling is performed by steering wheel.

5)Six pressure springs are located under instrument panel.

6)The space of separating amounts 10 - 15 mm.

7)The clutch is sometimes operated by compressed air.

8)Automotive engineering uses fluid flywheel clutches.

9)The clutch housing is filled with water.

10)This type of clutch works nearly without any slippage.

9. Complete the sentences with the correct word. The number of letters in each word is given in brackets:

10. Translate the following word-combinations into Russian:

Self-starting type, disengageable connection, the disk clutches, foot-operated, coupling, pressure springs, slip spring, flywheel, throttle lever, the elastic force, friction surfaces, compressed air, oil, vanes.

11.Write out all the key words from the text.

12.Make a plan of the text.

13.Compose a short summary of the text.

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Unit VIII

Change-speed gear

It is the purpose of the change-speed gear to adapt the movement of the car to the particular conditions. The internal combustion engine can develop the desired power only within a specified speed range. Therefore, the change-speed gear is meant to the driving speed to the particular situations with the engine operating at uniform speed as much as possible and to permit to back up the car. The particular ratio is called "gear" and, depending on the number of ratios, the change-speed gear or transmission is called a three-speed, four-speed, or five-speed gear or transmission.

Every change-speed gear or transmission has two gear shafts. The upper shaft is the main or sliding shaft, the lower shaft is the countershaft or layshaft. The clutch or drive shaft transmits the engine torque to the transmission via the clutch its one end is supported in the transmission housing and the other end in the crankshaft. It carries the clutch thrust plate causing the shaft to follow and the main drive gear, located inside the transmission housing and constantly in mesh with a gear on the countershaft. The main shaft is supported in the drive shaft and has longitudinal grooves carrying the individual gear clusters to be shifted in longitudinal direction by shifter forks. In addition to these two shafts, the reverse idler gear shaft is laterally supported in the housing it carries also the reverse idler gear for changing the direction of rotation when backing up. The gears of the countershaft are firmly connected to it and are permanently rotating due to the gears constantly in mesh.

In modern motorcars, especially in passenger cars, the "steering column gearshift mechanism" is preferred to the "stick control" arranged in the centre of the car. The gear-shift lever is mounted on the steering column underneath the steering wheel and its operation is very convenient since it is within easy reach. Besides, the passage from the left seat toward the right side-is free. The hand brake is not arranged in the conventional way next to the gear-shift lever but it is located underneath the instrument panel.

In some cars the gear-shift handle is located in the centre of the instrument panel and this is also a very convenient arrangement. In this case, the motion of the gear-shift handle is transmitted to the shitting lever of the transmission via some pipe passed through the instrument panel.

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The torque delivered by the transmission shaft has to be transmitted to the driving wheels. The drive of a motorcar can be performed both by the front wheels or rear wheels. In either case, some construction elements have to be incorporated between the transmission and the drive wheel, namely:

1)the cardan or universal shaft, required only for rear wheel drive from the engine arranged in the front end of the car;

2)the final drive and the differential or differential gear;

3)the axle shafts.

GLOSSARY

Change-speed gear – коробка передач, реверсивный механизм the internal combustion engine – двигатель внутреннего сгорания range – диапазон, радиус действия

is meant – здесь – предназначается

to back in the car – давать задний ход, двигаться в обратном направлении gear – шестерня

gear shaft – вал зубчатой передачи, вал с нарезанными шестернями counter shaft = lay shaft – промежуточный вал

clutch – сцепление

drive shaft – ведущий (приводной) вал torque – крутящий момент

thrust plate – упорный диск, упорная шайба groove – желобок, паз

gear clusters – блок шестерен to shift – смещаться

shifter fork – вилка переключения передач idler shaft – вал холостого хода

within easy reach – сподручное расположение (рулевой колонки) gear-shift mechanism – механизм переключения передач

the gear-shift lever – рычаг управления

Tasks

1. Find in the text sentences with the words given above and try to translate them. Guess the meaning of the following words:

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to adapt, particular conditions, power, driving speed, particular situations, to operate, transmission, three speed transmission, the upper shaft, sliding shaft, the lower shaft, motor car, front wheels, rear wheels, engine, end, to locate, longitudinal direction, forks, to change direction, permanently, constantly, passenger car, center of the car, operation, hand brake, instrument panel, driving wheels.

2.Find in the text adverbs.

3.Find in the text adjectives.

4.Find in the text participles.

5.Find in the text nouns in the function of attribute. Write out and translate these word combinations.

6.Find the sentences with modal verbs.

7.Find in the text the English equivalents to the following words:

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8. Find the answers to the questions:

1)What is the purpose of the change-speed gear?

2)What can the internal combustion engine develop?

3)What is called the particular ratio?

4)How many shafts does every change-speed gear have?

5)What are they?

6)Where is the main shaft supported?

7)What are gear clusters shifted by?

8)Where is the steering column gear shaft mechanism arranged?

9)Where is the hand brake located?

10)Where should the torque delivered by the transmission shaft be transmitted?

11)How can the drive of a motorcar be performed?

9. Compose a short summary of the text using the phrases:

The heading of the text is… The text informs about… The text goes on to say that…

The last passage is devoted to… Much attention is paid to…

In summary it should be noted that…

Unit IX

Universal shaft

In most vehicles with rear-wheel drive and with the engine arranged in the front end of the chassis, a propeller shaft is required leading the rear end. It is flexibly connected to permit the upward and downward movement of the rear axle casing.

The flexibility of this shaft is achieved by the cardan of universal joint; it is a joint permitting the transmission of a rotary motion while simultaneously vibrating.

Universal joints made of metal, are placed in sleeves or metal housings to be filled with special grease.

Instead of the universal joint it is possible to use rubber-vulcanized fabric