Федеральное агентство по образованию
Государственное образовательное учреждение высшего профессионального образования
Северо-Западный государственный заочный технический университет
Кафедра иностранных языков Иностранный язык
(Английский)
Учебно-методический комплекс
Информация о дисциплине
Рабочие учебные материалы
Информационные ресурсы дисциплины
Блок контроля освоения дисциплины
Санкт-Петербург
2008
Стоимость выполнения контрольной работы уточняйте при заказе.
Готовы следующие варианты:
К.р.4_Вариант 3
Контрольная работа 4
Вариант 3 I. Перепишите и переведите текст письменно.
LUBRICATION SYSTEM.
The lubrication system is very important for the high speed gasoline engine. The purpose of lubrication is to reduce the friction between the moving surfaces. It is essential that all the rotating and sliding engine parts should be kept well lubricated, and the lubricating system must be absolutely reliable.
Oil is used to lubricate the moving parts. A good lubricating oil should form an oil-film between the two sliding parts. The oil must, therefore, have sufficient viscosity at all engine working temperatures, but on the other hand it has not to be too viscous at atmospheric temperatures, or it will be difficult to start the engine.
Three types of lubricating systems have been used or are in present use on four cycle engines. These are (1) splash, (2) pressure-feed and (3) combination splash and pressure-feed.
In the pressure-feed system the engine is lubricated from the oil pan. This oil is circulated to various parts by means of a pump. The oil is picked up by the oil pump after having been drawn through an oil filter which is intended to prevent the particles of dirt from entering the engine. From the oil pump, oil is forced by pressure to the main bearings of the crankshaft.
The oil lubricates these bearings being distributed evenly over the surface by suitable oil grooves. A portion of this oil is splashed onto the lower part of the cylinder walls from where it is distributed around the entire cylinder wall and also into the hollow piston pins, some of it going to lubricate the piston bosses. Various other parts of the engine are lubricated by part of the oil under pressure or subject to splash.
II. Проанализируйте и письменно переведите следующие предложения.
1. Poor lubrication proves to cause considerable damage to the engine parts.
2. A certain temperature being reached, lubricating conditions got much worse.
3. The modern automobile is known to be a complex technical system composed of about 2000 parts.
4. To keep down the expressive temperature all internal combustion engines require some means of cooling.
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