海船船员考试
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
increase the liner area covered by the oil film
maintain an oil film on the lower liner where scuffing is prevalent
keep excess oil away from intake and exhaust ports
help cushion piston skirt side thrust by providing a hydrodynamic oil wedge
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
第2题：
The oil control rings will seal improperly and wear rapidly
The piston will overheat due to insufficient lubrication
Excessive oil will remain on the cylinder wall
Light brown smoke will emanate from the engine exhaust
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
第4题：
moving the governor control to stop
shutting off the lubricating oil supply
tripping the governor emergency stop lever
shutting off the fuel supply
第5题：
provide a reservoir for cylinder lubrication
pump oil into the combustion space for cylinder cooling
prevent excessive lubricating oil consumption
allow hydraulic oil film formation on the cylinder
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)
第7题：
less even torque
higher cylinder head temperatures
fewer power strokes per revolution
greater weight/size requirements
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
第9题：
prevent any lubricant from reaching
prevent excessive lubrication from reaching the combustion space
Provide metal-to-metal contact to seal the cylinder against blow-by
assure a positive means of scraping carbon accumulation from the cylinder
第10题：
wide compression rings are used
oil rings are located above the piston
chromium plating is used on all piston rings
oil rings are located near the bottom of the piston skirt