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Lubricating System.docx
Lubricating System
Principles of lubrication
A lubricant often has to perform many duties in any one situation, in addition to its fundamental job of reducing friction and wear. These duties may include acting as a rust preventative, a coolant, a sealing agent, a hydraulic fluid and a flushing agent to remove dust and metallic particles.
Lubrication, by maintaining a film of oil between the two surfaces, reduces the friction and hence the force required to move one or both of the surfaces.
Engine lubrication
While the primary duty of engine oil is to reduce friction and wear between the working parts of an engine, it also carries away a considerable amount of heat from the pistons, the valve stems and the main and connecting rod bearings. In addition, the oil forms a seal between the piston rings and the cylinder wall, and washes the working surfaces free of chemical deposits to protect them from corrosion.
Lubrication systems
The simplest method of lubricating an engine is to mix the oil with the petrol, as is done in two-stroke engines. As the oil enters the crankcase with the petrol and air, droplets settle on the connecting rod and main bearings and also lubricate the walls of the cylinder. In four stroke engines, the oil must be fed to the bearings in some other way.
Vocabulary:
lubrication – смазка, смазывание
lubricant – смазочный материал, смазка
friction – трение
wear – износ, амортизация
rust preventative - предотвращение ржавчины
coolant – смазочная охлаждающая эмульсия
sealing agent – герметик
fluid – жидкость
film – пленка, легкий слой; оболочка, перепонка
hence – следовательно
valve stem - стержень клапана
main bearing - коренной подшипник
seal – изолирующий слой, изоляция
deposit – отложение; отстой, осадок
droplet - капля
Answer the following questions:
1. What is the fundamental job of a lubricant?
2. Name other duties of the engine oil.
3. What is the simplest method of lubricating an engine?
4. How can the oil lubricate an engine?
Match two parts of the sentences
|
1. As the oil enters the crankcase with the petrol and air, 2. The primary duty of engine oil is 3. The simplest method of lubricating an engine is 4. The oil forms a seal between the piston rings and the cylinder wall, |
a) to mix the oil with the petrol, as is done in two-stroke engines b) droplets settle on the connecting rod and main bearings and also lubricate the walls of the cylinder c) and washes the working surfaces free of chemical deposits to protect them from corrosion d) to reduce friction and wear between the working parts of an engine |
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