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单选题Oil control rings used in two-stroke/cycle diesel engines are located near the bottom of the piston skirt in order to ()A increase the liner area covered by the oil filmB maintain an oil film on the lower liner where scuffing is prevalentC keep excess

题目
单选题
Oil control rings used in two-stroke/cycle diesel engines are located near the bottom of the piston skirt in order to ()
A

increase the liner area covered by the oil film

B

maintain an oil film on the lower liner where scuffing is prevalent

C

keep excess oil away from intake and exhaust ports

D

help cushion piston skirt side thrust by providing a hydrodynamic oil wedge

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相似问题和答案

第1题:

Lubrication for the main reduction gears used with diesel engines is usually supplied by

A.oil from the main engine sump

B.an independent lube oil system

C.the stern bearing head tank

D.the stem bearing sump tank


正确答案:B

第2题:

单选题
If the piston groove drain holes for the oil control rings become clogged, which of the following is likely to occur?()
A

The oil control rings will seal improperly and wear rapidly

B

The piston will overheat due to insufficient lubrication

C

Excessive oil will remain on the cylinder wall

D

Light brown smoke will emanate from the engine exhaust


正确答案: B
解析: 暂无解析

第3题:

Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.

A.The direction of pressure on the journal in four-stroke engine is continuously

B.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine

C.four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines

D.Low-stroke engines usually consume less lube oil than four-stroke engines


正确答案:A

第4题:

单选题
For most diesel propulsion and generator engines, the over-speed trip device will stop the engine by ()
A

moving the governor control to stop

B

shutting off the lubricating oil supply

C

tripping the governor emergency stop lever

D

shutting off the fuel supply


正确答案: D
解析: 暂无解析

第5题:

单选题
The primary purpose of oil control rings on a diesel piston is to()
A

provide a reservoir for cylinder lubrication

B

pump oil into the combustion space for cylinder cooling

C

prevent excessive lubricating oil consumption

D

allow hydraulic oil film formation on the cylinder


正确答案: A
解析: 暂无解析

第6题:

Which lubricating oil additive is used in diesel engines to reduce the tendency(倾向)for sludge and varnish to form on the engine parts?

A.Flash point improvers

B.Pour point improvers

C.Inhibitors

D.Foam suppressors(抑制物)


正确答案:C

第7题:

单选题
Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of ()
A

less even torque

B

higher cylinder head temperatures

C

fewer power strokes per revolution

D

greater weight/size requirements


正确答案: A
解析: 暂无解析

第8题:

The upper piston rings m large, slow-speed, two-stroke/cycle diesel engines are most effectively lubricated by oil ____.

A.fed from mechanical lubricators

B.thrown off from the main bearings

C.supplied from wick fed drip lubricators

D.flow from a centrifugal or banjo oiler


正确答案:A

第9题:

单选题
To function properly, oil control rings used on a diesel engine piston must distribute sufficient oil to all parts of the cylinder wall and must also().
A

prevent any lubricant from reaching

B

prevent excessive lubrication from reaching the combustion space

C

Provide metal-to-metal contact to seal the cylinder against blow-by

D

assure a positive means of scraping carbon accumulation from the cylinder


正确答案: C
解析: 暂无解析

第10题:

单选题
In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines, ()
A

wide compression rings are used

B

oil rings are located above the piston

C

chromium plating is used on all piston rings

D

oil rings are located near the bottom of the piston skirt


正确答案: C
解析: 暂无解析

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