II LUBRICATING SYSTEM

To reduce the friction between the working parts that are never completely smooth¹, and to absorb some heat one should use different oil lubricants. The most common type of lubrication is the combination of the force feed method² and splash lubrication. Oil is circulated and distributed within the engine by a gear type oil pump.

It maintains the sufficient³ pressure to supply oil in proper⁴ quantities to all moving parts. The oil from the oil pan is sucked into the oil passage and delivered to the oil pump. Then it is forced into the oil filters. There it is cleaned from particles and supplied to the main bearings of the crankshaft, to the connecting rod bearings, to the camshaft bearings and to the cylinder block units, valve mechanism and other parts requiring lubrication.

As a result a thin oil film is produced on the working surfaces that keeps them apart⁵. In this way friction and wear are reduced and the engine parts are cooled, cleaned and washed by the lubricant.

If one uses less lubricant than is required, the engine overheats, the bearings may melt and the piston is jammed in the cylinders. With too much lubrication the excess⁶ oil leaks into the combustion chamber and burns there. It results in snuff on the chamber walls and on the valves. If the meter shows no oil pressure one must stop the engine at once and check it.

Possible reasons may be the following:

1) the oil pipe-lines or the pump drive are damaged;

2) the bearings melt.

Further engine operation is impossible. It needs repairing. When the oil pressure lowers you must check the pipelines and oil filters and wash them if it is necessary, cool the oil or change it. If the gasket between the oil pan and crankcase or the crankshaft bearing seals are damaged the engine must be repaired at a service station.

If the oil pressure is too high you must:

1) warm up the engine at low revolutions because the oil may be thickened;

2) clean the oil pipe-lines⁷ because they may be obstructed with particles and dirt.

NOTES

¹smooth - гладкий

²force feed method - метод принудительного нагнетания

³sufficient – значительный, очень высокий

⁴proper - соответствующий

⁵ to keep apart - удерживать на расстоянии

⁶excess - избыток

⁷oil pipelines - маслопровод

Active Vocabulary to Text B, II

EXERCISES

1. Answer the questions.

1. Why is it necessary to lubricate the engine parts?

2. What are the most common types of lubrication?

3. What parts of the engine need lubrication?

4. How is the lubricant cleaned?

5. What happens when one uses too much lubrication?

6. What is the result of poor lubrication?

7. When is engine operation impossible?

8. What causes the lowering of oil pressure?

9. What must be done when the oil pressure is too high?

2. Name the main devices that form the lubricating system.

3. Describe the principles of engine lubrication.

4. Describe the results of too much engine lubrication.

5. Describe the results of poor engine lubrication.

6. Describe the reasons for the:

a) absence of the oil pressure;

b) oil pressure reduction;

c) oil pressure increase.

7. Read the dialogue. Learn it and act out in class. Practice with your friend and make up your own dialogue according to the pattern.

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