Vocabulary

vehicle - транспортное средство

to carry out - выполнять

self-propelled - самоходный

purpose – назначение, цель

is intended for …- предназначен для …

capacity - мощность, емкость

to tip - опрокидывать

cargo - груз

crawler – tractor - гусеничный трактор

cargo (load-carrying) capacity - грузоподъемность

wheeled tractor - колёсный трактор

dump truck - самосвал

steerable - управляемый

frame - рама

to equip - оборудовать

to attach - прикреплять

belt pulley - ремённый шкив

storage battery - аккумулятор

shaft – вал

ЗАДАНИЯ К ТЕКСТУ:

1. Прочтите и переведите текст, пользуясь словарём.

2. Ответьте на вопросы:

1. What is the automobile intended for? 2. What is the classification of transport vehicles? 3. What is the classification of trucks according to their load – carrying capacity? 4. Give some examples of special – purpose vehicles. 5. What are competition vehicles designed for? 6. What is the difference between framed and frameless vehicles? 7. Which prime mover may carburettor, diesel and electric motor be powered by? 8. Is the tractor used for road building? 9. Which type of tractors is used for field tasks? 10. Special-purpose tractors are used for definite jobs or for jobs under certain conditions, aren’t they?

Fundamentals of Automobile

Basically, the automobile consist of four components:

1) The engine.

2) The framework, or support for the engine and wheels.

3) The power train, or mechanism that transmits the power from the engine to the wheels.

4) The body.

To these may be added a fifth components, the car-body accessories: the heater, light, radio, and other devices that contribute to the convenience and comfort of the driver.

The Engine. The engine is the source of power that makes the wheels around and the car move. It is usually referred to as internal combustion engine because gasoline is burned with in its cylinders, or combustion chambers. Most automobile engines have six or eight cylinders, although some four-, twelve- and sixteen-cylinder engines are in use.

Fuel System. The fuel system is designed to store liquid gasoline and to deliver it to the engine cylinders in the form of vapor mixed with air. It consists of a fuel tank in which the gasoline is stored, a fuel line, through which the gasoline can be brought from the tank to the engine, a fuel pump, which pulls the gasoline through the fuel line, and a carburetor, which mixes the gasoline with air.

Electric System. The electric current performs several jobs on the car. It cranks the engine, furnishes electric sparks at the spark plugs that ignite the compressed mixture in the cylinders, operates the radio and heater motor, suppliers light for night driving, and operates gauges on the dash of the car that indicate charging rate, oil pressure, engine temperature, and the amount of the fuel in the tank.

The electric system consists of the storage battery, cranking motor, generator, distributor, ignition coil, and spark plugs as well and switches that connect these various units. Light, radio, heater, indication rouges and other electrically operated devices are usually considered as accessory devices, since they are not absolutely necessary to the operation of the car.

Power Train. The power that engine develops must be transmitted to the car to wheels, so that the wheels will rotate and cause the car move. The power train performs this job providing in the process several different gear ratios between the engine crankshaft and wheels, so that the crankshaft may rotate approximately four, eight, or twelve times to cause the wheels to rotate once. The power train consists of a series of gears and shafts, which mechanically connect the engine shaft with the car wheels and contains a clutch transmission or change gears, a propeller or cardan shaft, and a final drive.

(a) Clutch. The clutch permits the driver to connect the crankshaft to, or disconnect if from, the power train its main part is a friction disk pressed tightly by springs to the smooth face of the engine flywheel. The flywheel is attached to the end of the engine crankshaft, and when the clutch is engaged, the friction disk is held against the flywheel so that it revolves with the flywheel. When the clutch foot pedal is depressed the friction disk movies away from the flywheel face and stops revolving; when the foot pressure on the clutch pedal is removed, the springs again force the friction disk against the flywheel face, so that it once more rotate with the flywheel. The rotary motion is transmitted through the clutch shaft to the transmission gears and from there through the propeller shaft on to the rear wheels.

(b) Transmission. The transmission or change gears provide a means of varying the gear ratios of the engine crankshaft and the wheels. There are three main gear positions in the automobile transmission: low gear, second gear, and high gear. Thus the engine crankshaft may turn four, eight, or twelve times for each wheel revolution (approximately). In addition, a reverse gear is provided that permits backing the car.

The varying gear ratios are necessary since the engine does not develop much power at low engine speeds: it must be turning at a fairly high speed in order to deliver enough power to start the car moving. Thus, on first starting, the gears are placed in low speed so that the engine crankshaft will turn approximately 12 times for each wheel revolution. The clutch is then engaged, so that the power is applied to the wheels. Car speed increases with engine speed until the car is moving 5 or 10 miles per hour, at which time the engine crankshaft may be turning as many as 2.000 r. p. m. The clutch is then disengages, the gears are shifted in second, and the clutch is again engaged. A still higher car speed is obtained as engine speed is again increased; the gears are then shifted in high, the clutch being disengaged and engaged for this operation is before.