3. Read and translate the text. Gearbox. Automatic transmission

The object of a gearbox is to provide a means of obtaining the most efficient engine speed in relation to the speed required, at the road wheels.

The gearbox is quite a complicated assembly of gears of different sizes, arranged so that certain combinations of gears can be engaged to enable one to drive another. If a larger gear drives a smaller one, a high ratio is produced, and if a smaller gear drives a larger one a lower ratio is provided. Most car gearboxes have four “speeds”, which means that by moving the gear lever inside the car one of four different ratios can be selected. A reverse gear is also included, to enable the car to be driven backwards for manoeuvering.

In a low ratio gear the engine runs fast while the car is moving quite slowly. As higher gears are engaged, the engine speed drops but the car moves faster. A low ratio is therefore used when greater engine power is needed to start the car from rest, to accelerate quickly and to climb steep hills. For normal cruising along the road a high gear is selected.

While many drivers like to control their cars by the normal gearbox and gear lever, some motorists prefer to drive with as little effort as possible. Automatic transmission takes much of the work away from the driver who only has to accelerate when he wants to go faster and brake, when he wishes to slow down or stop. All the necessary gear changing is done quite automatically within the transmission. There is no clutch pedal, only an enlarged brake pedal and an accelerator. A selector lever replaces the normal gear lever.

4.Answer the questions:

1) What is the object of a gearbox?

2) What does the gearbox consist of?

3) When is a high ratio produced?

4) When is a lower ratio provided?

5) How many speeds have most cars gearboxes?

6) What is used to enable the car manoeuvering?

7) How does automatic transmission work?

5.Find the right translation:

1. top gear

2. second gear

3. bottom gear

4. high ratio

5. low ratio

6. gear lever

7. reverse gear

8. assembly of gears

9.in a low ratio gear

a) передача заднього ходу

b) на нижніх передачах

c) сукупність зубчатих коліс

d) високе передатне число

e) низьке передатне число

f) важіль переключення передач

g) друга ступінь (у коробці передач)

h) найвища передача

i) перша передача

Unit 25 Rear axle. Rear axle differential action

1. Memorize the new words and word-combinations:

1.conventional

2.propeller shaft

3.pinion

4.crown wheel

5.bend

6.arrangement

7.differential gear

звичайний

карданний вал

ведуча шестерня головної передачі

ведома шестерня головної передачі

поворот

набір

диференціальна передача