General

The primary purpose of engine lubrication is to prevent metal-to-metal contact between the moving parts. The result of such metal-to-metal contact is friction. Friction is the resistance to motion between two bodies in contact with each other.

The friction resulting from metal-to-metal contact causes loss of power, rapid wear of surfaces and a rise of temperature which can lead to a failure of parts. So the action of a lubricating oil is to keep friction at a relatively low value.

Friction can be divided into three classes: dry, greasy and viscous. Dry friction is the friction between two solids, that is the friction resulting from metal-to-metal contact of moving parts. Greasy friction is the friction between two solids coated with a very thin film of oil. When greasy friction exists, the resistance to motion between surfaces is much less than with dry friction. Greasy friction may exist in bearings and between piston rings and cylinder walls when the engine is first started. At this time, most of the lubricating oil may have drained from the surfaces so that only a thin film remains. So, before the lubrication system goes to work and the surfaces are supplied with more oil, there is only greasy friction between them. Viscous friction is the friction between adjacent layers of a liquid. In engines, viscous friction occurs during relative motion between two lubricated surfaces. The internal friction between the layers of a fluid oil or viscous friction is much smaller than between solid objects.

 

Exercise 2. Translate the following words and word combinations.

Moving parts, metal-to-metal contact, resistance to motion, friction, dry friction, greasy friction, viscous friction, inter­nal friction, loss of power, failure of parts, load, lubricating oil, fluid, value, temperature rise (rise of temperature), layer, adjacent layer, thin film, wear of surfaces.

 

Exercise 3.

a) Translate the following verbs:

to prevent, to lubricate, to result (from, in), to lead (to), to keep, to coat (with), to exist, to drain (from), to remain, to supply, to occur, to start.

b) Choose the words and word combinations that can be used with the verbs given above:

Example: to prevent failure

to prevent metal-to-metal contact

to prevent loss of power.

engine parts, failure, metal-to-metal contact, bearing, greasy friction, losses of power, lubricating oil, viscous friction, engine, thin film, rapid wear of surfaces, at a low value.

c) Translate the nouns formed from the verbs. What other derivatives can you form from these verbs.

To prevent – prevention, to lubricate – lubrication, to exist – existence, to drain – drainage, to occur – occurrence, to coat – coating, to start - starting.

 

Exercise 4. Form nouns with the help of the suffixes -ion, -er,-or. Translate the nouns.

to operate – діяти, to compress – стискати, to rotate – обертати, to correct – виправляти, to exhaust – випускати, to combust – спалювати, to ignite – займатися.

to teach – вчити (навчати), to compress – стискати, to operate – діяти, працювати, to transform – перетворювати, to burn – горіти.

 

Exercise 5. Form adverbs with the help of suffix -1у. Translate the adverbs.

Usual – звичайний, great – великий, partial – частковий, actual – фактичний, complete - певний

 

Exercise 6.Form the adjectives by adding the suffix “-ful” and “-less”. Translate them.

Use – користь, success – успіх, power – потужність, force – сила.

Exercise 7.Pick out Ukrainian equivalents to the following English words and word combinations.

a) metal-to-metal contact, moving parts, friction, resistance, to cause, loss of power, wear, failure, dry, solid body, liquid, layer, adjacent, relative motion, to occur.

b) tертя, втрата енергії, сухий, тверде тіло, рідина, виникати (мати місце), дотик металу до металу, опір, знос, частини що рухаються, спричиняти, поломка (відмова), шар (прокладка), суміжний, відносний рух.

 

Exercise 8. Put in the missing words and expressions.

(friction, wear of surfaces, viscous friction, load, solid objects, relative motion, is coated, drains, film of oil, temperature rise, a failure of parts)

A rise of temperature caused by dry friction can lead to ________.

Resistance to motion resulting from metal-to-metal contact is called ______.

Greasy friction exists when there is only a very thin ________ on the surfaces.

The internal friction between the layers of a fluid oil is called _____.

Viscous friction takes place during _______between two lubricated surfaces.

Dry friction results in rapid _______ of surfaces and __________.

At greasy friction, each moving surface ________ with a film of oil.

Resistance to motion, or __________ increases with __________.

Most of the lubricating oil ___ from the surfaces of the moving parts.

The viscous friction between the layers of a fluid oil is much smaller than dry friction between _____.

 

Exercise 9. Answer the following questions.

What is the primary purpose of engine lubrication?

What does friction result from?

What is friction?

What does friction increase with?

What is the action of a lubricating oil?

What are the types of friction?

What is dry friction?

What is greasy friction?

What is viscous friction?

Where does viscous friction occur?

Is viscous friction much smaller than dry or greasy friction?

Which is smaller, dry or greasy friction?

Exercise 10. Translate the text in the written form.

The type of friction encountered in the engine is normally viscous friction, that is the friction between adjacent moving layers of oil. If the lubrication system does not function properly, sufficient oil will not be supplied to moving parts, and greasy or even dry friction will result between moving surfaces. This would cause at the least considerable power loss, since power would be used in overcoming these types of friction. At the worst, major damage would occur to engine parts as greasy or dry friction developed. Bearings would wear with extreme rapidity; the heat resulting from dry or greasy friction would cause bearing disintegration and failure, so that connecting rods and other parts would be broken.

Insufficient lubrication of cylinder walls would cause rapid wear and scoring of walls, rings and pistons. A properly operating engine lubricating system supplies all moving parts with sufficient oil so that only viscous friction is obtained.

 

Exercise 11. Pick out Ukrainian equivalents to the following English words and word combinations.

a) viscosity, flash point, fluidity, fire point, pour point, fluid, to increase, to decrease, a device, to determine, grease, a definite amount, vapour, opening, measurement, to refer, evaporation, suitability, a thicken.

b) в‘язкість, пар, точка спалахування, точка спалаху, текучість, рідина, точка текучості, зростати, зменшуватися, прилад, визначена кількість, визначати, змащуюча речовина (змазка, тавот), отвір, вимірювання, придатність, застигати, відноситися, випаровування.

Exercise 12. Read and translate the text.