Exercise 6. Discuss the following.
1. Where is cylinder head located?
2. What are the symptoms of the cracked cylinder?
3. Is it easy to cracks? Why?
4. Describe the two methods of repairing cracks.
5. What is the best method to repair cracks? Explain your point of view.
Lesson 7. DIESEL ENGINE MAINTENANCE
Exercise 1. Read and learn the following words and expressions:
Vocabulary notes:
1. maintenance – содержание и техническое обслуживание, техническая эксплуатация, уход, ремонт
2. daily – ежедневно
3. dipstick – футшток
4. to stand still – находиться не в рабочем состоянии
5. at least – по крайней мере
6. draining – слив
7. to unscrew – отвинчивать
8. to screw – завинчивать
9. drain plug – сливная пробка
10. bottom – дно, днище
11. crankcase – кратер двигателя
12. to (re)fill – наполнять (вновь)
13. to wipe – протирать
14. inside – внутри
15. rag – ветошь
16. fluff – пух, ворс
17. cotton waste – хлопчатобумажная ветошь
18. to dip – погружать, окунать
19. lube oil suction strainer – фильтр масла на входе
20. sump – отстойник, сборник, сточная цистерна
21. frequently – часто
22. crack – трещина
23. to examine – проверять
24. deposits – отложения
25. carbon – нагар
26. excessive – излишний
27. externally – с наружной стороны
28. scale – накипь
29. to adjust – регулировать
30. readings – показания, данные, замеры
31. lever – рычаг
32. alignment – регулировка, выравнивающая центровка, настройка, просветка (линий вала)
Exercise 2. SCANTHE TEXT AND BE READY TO DISCUSS IT.
Check the lube oil pressure daily. The pressure should be 1,5 kg per sq. cm = 21Ibs/sq. in (psi). keep the oil level to the full mark of the dipstick. Make control when the engine stands still. The lube oil should be changed the first time after 50 working hours, the next time after another 150 working hours and then at least once a year. Draining is made by unscrewing the drain plug at the bottom of the crankcase just after stopping the engine when the oil is warm and easy to drain. Before refilling with fresh oil wipe out the inside of the crankcase with a clean rag (use material free from fluff, do not use cotton waste). Dip the rag in gas oil and clean the lube oil suction strainer placed on the drain plug and clean the sump. When changing the lube oil, clean the lubricating oil filter with petrol or gas oil. Refill the sump with fresh lube oil.
Pistons should be examined frequently for cracks. The upper piston rings should be examined once a month during the first six months’ service and then as necessary depending on their condition. At intervals of six months, piston heads, if cooled, must be examined for deposits of carbon in cooling spaces – and cooling pipes. Exhaust valves, manifold and cylinder ports should also be examined and excessive carbon deposits should be removed. Cylinder liners must be examined externally for deposits of scale. The liners should also be examined for wear and renewed if necessary. The clearance of the connecting rod top and bottom ends should also be examined and adjusted if necessary. At intervals of one year the maneuvering gear should be examined for wear at the joints of levers and rods. The alignment of the crankshaft should be checked and corrected if necessary. The main bearings should be examined and readings taken for wear.
Exercise 3. Answer the following questions.
1. How often should the lube oil pressure be checked?
2. What should be the pressure?
3. When should the lube oil be changed the first time?
4. How is draining made?
5. Where is the drain plug positioned?
6. When is the oil easiest to drain?
7. When is it necessary to wipe out the inside of the crankcase?
8. What should the pistons be examined for?
9. Where is usually carbon deposited?
10. What should be done with carbon deposits?
11. How often should the maneuvering gear be examined?
Exercise 4. Translate from English into Russian.
1. If the allowed overspeed was exceeded, the force would be sufficient to lift the suction valves off their seats.
2. If the cooling water supply was insufficient, the engine would be overheated.
3. Atomization and spreading of the fuel depend largely on the injection system.
4. Compression, cylinder dimension and cooling arrangements determine the temperature conditions.
5. Conditions for good combustion must be proved because the diesel engine has to handle the entire job of mixing and igniting fuel inside the cylinder in an extremely short time.
6. In diesel engine there are two general types of surfaces – those inside the cylinders and those in bearings.
7. Cylinder lubrication has two purposes – to maintain the required film to separate the liner surface and the surfaces of the piston rings and to act as a seal to prevent gases from blowing past the rings.
8. In large engines a separate mechanical force-feed system is used to lubricate the cylinder walls.
9. When fuel burns in the cylinders of a diesel engine only about one-third of the fuel’s heat energy changes into mechanical energy and then leaves the engine in the form of brake horse-power.
10. Many engines use oil coolers to remove the heat in the lubricating oil.
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