1.2.4 船舶柴油机润滑系统

1.2.4 船舶柴油机润滑系统

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

A.oil from the main engine sump B.an independent(独立的) lube oil system

C.the stem beating head tank D.the stern bearing(艉轴承) sump tank 注 在内燃机船上，减速齿轮箱的滑油系统与主机的滑油系统是相互独立的，以避免发动机产生的污染物损害减速齿轮。B

By which of the following types of lubricating oil systems are lubricating oil systems for diesel engine journal bearing usually lubricating ?

A. Splash B. Gravity C. Pressure D. Bypass

注 在滑油系统中柴油机曲轴轴颈轴承（主轴承）为压力润滑。C

* 3. Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are ____.

A.operated manually once an hour

B.operated until the engine has started

C.placed into operation only at maximum load

D.adjustable to meet lubrication requirements

注 柴油机气缸注油器一般都是小型的往复式泵，该泵能调节以满足不同的润滑要求。D

4. The lube oil cooler is located after the lube oil filter in order for ____.

A.the filter to operate more efficiently

B.the lube oil cooler to be bypassed

C.positive lube oil pump suction to be assured

D.galvanic action(电流作用) in the cooler to be

注 滑油冷却器位于油滤器之后，主要是为了使滤器运行效率更高（温度较高时易过滤净化）。A

5.Why do we use cylinder oil?

A. To neutralize the sulphur and get a lubricating oil film between piston rings and liner

B. To get a lubricating oil film between piston rings and liner

C. To neutralize the sulphur in the fuel

D. To avoid blow-by

注 汽缸油是用来中和酸和在活塞环和气缸之间形成油膜润滑 A

6. In a pressure type lubricating system,the lube oil service pump normally takes suction from the sump tank and discharge directly to the ______.

A. lube oil cooler

B. main thrust bearing

C. gravity feed tank

D. lube oil heater

注 在压力润滑系统中，日用滑油泵通常从滑油储存柜吸进并且直接供给滑油冷却器。A

7. The common method of applying oil to the cylinder walls is by means of small pump assembled in units,known as _______.

A. mechanical lubricator

B. forced feed system

C. lubrication function

D. bearing lubrication

注 通过小的泵把滑油提供给气缸壁的方式叫机械润滑。A

8.Each of the engine cylinders is lubricated from a lubricator,driven by _____.

A.a separated motor

B.the engine’s piston

C.the engine’s camshaft

D.a turbine

注 驱动每个气缸滑油注射器的是凸轮轴 C

9. The lube oil in the bearings is drawn from a ____，usually located in the bedplate

A.tank B.sump C.vessel D.bottle

注 轴承的润滑油从油底壳吸入，油底壳一般位于机座内，B

10. The oil is drawn from a drain tank through ____,one of a pair of pumps, into one of fine filters.

A.a strain tank B.a head tank C.a service tank D.a strainer 注 滑油从泄油柜吸入，前后经过一个粗滤器、一台油泵、一个细滤器等。D 11. The cross-head pin bearings are white metal lined shells lubricated by means of ____.

A.low pressure pumps B.centrifugal pumps

C.high pressure pumps D.mechanical compressors

注 十字头销轴承有白合金衬里，并通过高压油泵来润滑。C

12. The lubricating system for the cylinder walls is different from the bearings in that the oil for former one is supplied in ____ while that for latter one is ____.

A.sufficient quantity; measured

B.measured quantity; sufficient

C.excessive quantity; sufficient

D.the less quantity the better; the more the better

注 气缸润滑系统与轴承润滑系统不同之处在于，前者提供滑油是经过计量的，而后者提供无限量的滑油（后者属于消耗型）。B

13. In some designs the cylinder oil is timed so that the oil injects only on the ____.

A.piston crown(活塞头) B.piston groove

C.piston skirt D.piston ring belt

注 在一些设计中，气缸油的注入是定时的，以便气缸油仅仅喷射在活塞环带区域。D

14. Large marine diesel engines of crosshead construction generally have two systems of lubrication:a total loss system feeding the ____ and a recirculation system lubricating the running gear and cooling the piston.

A.cylinder liners and piston rings B.main bearings

C.crankpin beatings D.turboblower

注 十字头结构的大型船用柴油机一般有两套润滑系统：供应缸套和活塞环的全消耗系统；润滑轴承和冷却活塞的循环系统。A

* 15.In an engine with a pot-shaped piston, some lubricating oil from the main bearing will pass along a ____ in the crankshaft to the bottom end bearing and then up a connection rod to the gudgeon pin.

A.telescopic pipes B.large bore C.drilled passage D.tied rod

注 对于筒状活塞的发动机，来白主轴承的一些滑油沿着曲轴内部的油道到下端轴承，然后沿连杆到达活塞销。C

16. A lubricant often has to perform many duties in any situation,in addition to its fundamental job of ____.

A.resisting oxidization B.reducing friction

C.promoting moving speed D.developing inertia

注 润滑剂除了其基本功用是减少摩擦之外，还有其他许多作用。B

17. There should be a lubricating oil ____ between the main bearings and the crankshaft.

A.film B.cap C.lacquer (漆) D.shell

注 主轴承和曲轴之间应该有润滑油膜。A

18. In a diesel engine lube oil system, which of the following parts should be

lubricated first?

A.Camshaft bearings. B.Main bearings.

C.Piston crowns. D.Cylinder walls.

注 柴油机部件中，主轴承应首先被润滑。B

19.What is the main task of the lubrication oil in the engine?

A.To lubricate and cool the engine

B.To lubricate engine

C.To transfer heat out of the engine

D.To keep the crankcase clear and free of deposit

注 滑油在主机中的作用是润滑和冷却主机。A

20.The cylinder oil is supposed to be _______.

A.alkaline B. acidic C. Neutral D.any one of the other alternatives 注 汽缸油呈碱性。A

21. Generally the function of lubrication is to form of a film of lubricant between any two surfaces that have relative ____,so that surfaces don’t get touch with each other.

A.gravity B.motion C.ratio D.density

注 一般地说，润滑的功能是在具有相对运动的两个表面之间形成油膜，以免表面之间直接接触。B

* 22.The lubricating oil is pumped from the drain tank, very often with ____ in the suction line.

A.a filter B.a strainer

C.a magnetic filter(磁性过滤器) D.a fine strainer

注 润滑油从泄油柜被泵送吸入管路经常安装磁性滤器，用来去除金属颗粒C

23.In a diesel engine, the function of lubrication oil is to provide _____.

A.a film between the shafts and bearings

B.cooling of the pistons and bearings

C.for removal of dirt or metal particles resulting from wear

D.Any one of the other alternatives

注 在柴油机中滑油的作用是提供：在曲轴和主轴承之间形成油膜，冷却活塞和轴承，带走细屑。 D

24.An excessive pressure drop a across a lube oil strainer could indicate _____.

A.that the strainer needs clearing

B.that the relief valve is stuck open

C.that the strainer is OK

D.Any one of the other alternatives

注 滑油过滤器的两端有大的压降，这时滤器应该被清洗。A

25. A dirty diesel engine oil filter element can best be detected by ____.

A.visual inspection of the elements B.the pressure drop across the filter

C.high lube oil sump temperature D.decrease in oil viscosity from the filter 注 柴油机滑油滤器芯件脏污可以通过滤器前后的压力降（压差）来判断。B 26. In the two stroke diesel engine, it is designed so that the oil impingement is timed to proceed only on the piston ring belt during ____.

A.compression stroke B.suction stroke C.expansion stroke D.exhaust stroke 注 二冲程柴油机，设计成定时注入滑油，以便油只在压缩冲程射到活塞环带上。A

27. The piston crown employs the usual jet-shaker ____ principle with an arrangement of cooling bores in the crown so that the surface temperatures of the crown are moderate with a very even distribution.

A.water cooling B.oil cooling C.air cooling D.combined cooling 注 按照在活塞顶冷却孔腔设计的油冷原理，活塞顶采用射油振荡器，以使活塞顶的表面温度均匀适中。B

* 28. In engines with ____ system, the lubricating oil can be added to the engine through the filling hole in the crankcase cover, by using a hand oil can, or through the separator pipe.

A.lubricating oil B.dry sump C.circulated tank D.wet sump

注 带有滑油系统的柴油机可用手提油壶或分油机管道，把滑油通过曲轴箱盖上的加注孔加到发动机里。D

29. The cylinder oil is pumped into the cylinder (via non-return valves) when the piston rings pass the lubricating orifices, during ____.

A.the upward stroke B.the downward stroke

C.the power stroke D.the suction stroke

注 在上冲程期间当活塞环经过润滑油孔时，气缸油泵入气缸（经止回阀）。A 30. The following options are all the functions of lubricating oil except ____.

A.removing heat and deposits B.neutralizing acidic products

C.lubricating D.improving combustion efficiency 注 除了提高燃油效率外，下列全是润滑油的功能。D

31. ____ diesel engines generally have two systems of lubrication:a total loss system feeding ____ and a circulating system lubricating the running gear and cooling the pistons.

A.Large cross head type; cross heads B.High speed; the cylinders

C.Large cross head type; the cylinders D.Four-stroke; pistons and cylinders 注 大型十字头柴油机一般有两套润滑系统：润滑气缸的是完全消耗型润滑系统和润滑运动装置和冷却活塞的循环系统。C

32. In some diesel engine designs, the injection of cylinder oil is timed to impinge when the piston ____ and only impinge on ____.

A.is coming upward; cylinder ring belt

B.is going downward; piston ring belt

C.is coming upward; piston ring belt

D.is going downward; cylinder ring belt

注 在某些柴油机设计中，当活塞上行时气缸注油器定时向气缸中注入气缸油，且只注射到活塞环带上。C

33. Large crosshead type engine generally has two lubrication systems,a function performed only by cylinder oil system is ____.

A.lubricating B.cooling C.sealing D.cleaning

注 大型十字头柴油机通常有两套润滑系统气缸油的一个功能是起密封作用C 34. Large crosshead type engine generally has two lubrication systems,a function performed only by crankcase oil system is ____.

A.lubricating B.cooling C.cleaning D.neutralizing

注 大型十字头柴油机通常有两套润滑系统曲轴箱油的功能是起冷却作用。B 35. In an oil cooler circulated by sea water, the oil is at a larger pressure the result being that any leak in the cooler will mean a loss of ____.

A.oil B.sea water C.refrigerant D.fresh water

注 在海水循环的油冷器中，油压比水压高，结果是油冷器发生泄漏时，只损失了滑油。A

36. In large marine diesel engines cylinder oils usually contain additives formulated to impart the ____ to clean the rings and grooves.

A.inefficiency B.oiliness(润滑性) C.detergency(去垢性) D.purity

注 大型船用柴油机的气缸油通常含有添加剂，其中清洁剂用来清洁活塞环和环槽。C

37. Oi1 is supplied to the cylinder wall and ____ by means of mechanical lubricators

A.the cylinder cover B.the piston rings C.the piston crown D.the piston skirt注 润滑油通过机械式的注油器供应到气缸壁和活塞环。B

38. The ____ of the lubricant should be sufficient to hold the film together, but it

should allow the lubricant to flow easily.

A.specific gravity B.viscosity C.acid value D.calorific value

注 润滑剂的黏度应足够高以维持油膜但也不能过高要保证它能自由流动。B

39.The crank chamber oil_____.

A.can be recovered

B.is only supplied to cylinder

C.only feeds the main bearing

D.is a kind of detergent

注 曲柄箱油是可回收的 A

40. The film of oil between the rings and the liner is not only essential for the lubrication but also plays an important part in achieving ____.

A.an oil seal B.removing heat C.a gas seal D.cooling the piston 注 活塞环和缸套之间的油膜不仅对润滑很重要，而且在实现气封方面起到很重要的作用。C

41. The main function of the lubrication system is to enable ____ of a film of oil between the moving parts.

A.The information B.The formation C.The scatter(分散) D.The friction 注 滑油系统的主要功能是在运动部件之间形成油膜。B

42. Which of the following will be the function of lubricating oil used in marine engines?

A.To remove heat from oil cooled pistons. B.To wash away wear detritus.

C.To neutralize acidic products. D.All of the above.

注 船用柴油机的滑油起多方面的作用，如带走热量、清除磨屑、中和酸性物等。D

43. The lube oil to lubricate the surfaces of the cylinder liners is spread over by the ____.

A.sliding (滑动的) piston rings B.engine's camshaft

C.small pumps D.forced feed system

注 润滑缸套表面的滑油是由滑动的活塞环来布油的。A

44. Which of the following methods is normally used to lubricate bearings in a small high,speed diesel engine?

A.Splash lubrication. B.Pressure lubrication.

C.Sight feed lubricators(可视注油器) D.Mechanical lubricators.

注 小型高速柴油机的轴承往往采用压力润滑。B

45. Two important considerations for the proper lubrication of a diesel engine include, the delivery of the oil in sufficient amount, and the ____.

A.cetane number B.pour point C.viscosity temperature D.quality of the oil 注 柴油机润滑泊应满足两个基本要求，即足够的数量和好的质量。D

46. The lube oil pump used ina diesel engine is a ____.

A.volute pump B.centrifugal pump C.diaphragm pump D.gear pump 注 柴油机中的滑油泵一般采用齿轮泵，或浸没式离心泵。D

47. With respect to the flow of lubricating oil through a diesel engine, the lube oil coolers are located after filters in order to ____.

A.allow filtration(过滤)of less viscous oil(黏性油)

B.decrease the pressure drop across the filter

C.improve overall(全部的)filtration

D.All of the above.

注 滑油冷却器位于油滤器之后，主要是为了使滤器运行效率更高（温度较高时易过滤净化）。D

48. Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the ____.

A.main bearings B.connecting rod bearings

C.piston pin bushings D.All of the above.

注 柴油机曲轴内的油槽用来向主轴承、连杆轴承和活塞销套管等提供滑油。D

49. Lubricating systems for diesel engines are usually designed to initially provide lube oil to the ____ engine.

A.camshaft bearings B.main bearings C.piston crowns D.cylinder walls

注 柴油机润滑系统首先应能向主轴承提供滑油。B

50. On a medium-speed main propulsion diesel engine, the crank-pin or crank journal bearings receive lubricating oil from ____.

A.a spindle(锭子或主轴)lubricator B.an oiljet(喷射器)

C.internal splashing D.drilled passages in the crankshaft 注 中速主推进柴油机，曲柄销轴承是由曲轴内钻孔的油槽供油的。D

51. Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each cylinder during ____.

A.the power stroke B.the compression stroke

C.low load operation only D.periods of standby

注 低速主推进柴油机，气缸油是在压缩冲程期间进入的。B

52. For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a(an) ____.

A.oil spray B.oil bath

C.oil control rings D.drilled passage through the camshaft 注 对于柴油机活塞冷却，滑油可通过飞溅式供应到活塞。A

53. A magnetic strainer is used in the diesel engine reduction gear oil system to remove small particles of ____？

A.water B.babbitt(巴比合金) C.iron or steel D.acids

注 柴油机减速齿轮箱油系统中，磁性滤器用来去除铁屑等。C

54. In a bypass type lubrication system for a diesel engine, the dirty oil line to the centrifuge should be taken from the ____.

A.lube oil pump suction Iine B.lube oil pump discharge line

C.bottom of the lube oil sump D.outlet from the lube oil heater

注 在柴油机旁通式润滑系统中，通向分油机的脏油管路应来自油底壳的底部。C

55. A diesel engine piston ring face is in direct contact with the ____.

A.top of the ring groove B.cylinder liner oil film

C.bottom of the ring groove D.back of the ring groove

注 柴油机活塞环的表面直接与缸套的油膜接触。B

56. Dirt should not b8 allowed to contaminate a grease lubricant because the ____.

A.dirt will cause corrosion of bearing

B.bearings will leak oil excessively

C.dirt is very abrasive(研磨的)when mixed with grease

D.grease will become inflammable

注 污物与油脂混合后，会产生很大的磨损作用，因此应防止油脂被污物污染。C

57. Which of the processes listed consumes the greatest amount of power while producing the greatest amount of heat?

A.Overcoming sliding friction(滑动摩擦).

B.Overcoming rolling friction.

C.Overcoming fluid friction.

D.Overcoming oil wedge(楔入) friction.

注 克服滑动摩擦需要消耗最大的功，同时产生最多的热量。A

58. The function of lubricating oil is to ____.

A.reduce friction between moving surfaces

B.provide even distribution of bearing wear

C.reduce the accumulation of harmful detergents

D.maintain a constant oil temperature output at each bearing

注 滑油的作用是减少运动部件之间的摩擦。A

59. is a device designed to prevent the passage of unwanted solids into the system.

A.steam trap B.check valve C.separator D.strainer

注 “stainer ”和“filter ”都是滤器，但严格地说，前者是粗滤器，后者是细滤器，它们都能阻止外界颗粒物进入到系统。D

60. Two main lubricating oil pumps are usual and are obligatory in ____.

A.container ships B.bulk carriers C.passenger ships D.barges 注 船上通常有两台主润滑油泵，但在客轮上是强制性的。C

61. The cylinder oil will have to neutralize the acidic products of combustion and have good ____ properties to keep the metal surfaces clean.

A.detergent B.de-oiling C.defrosting D.demulsifying

注 具有清洁作用的添加剂用来保持金属表面清洁。A

62. As for turbine oil, contact with water in the form of steam will be inevitable so

good ____ properties will be essential.

A.defrosting B.de-oiling C.demulsifying D.dehumidifying

注 对于透平油，因为要与水蒸气接触，因此必须具有良好的抗乳化性能。C

63. The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its ____.

A.specific gravity(比重) B.viscosity

C.TBNnumber D.hydrolytic(水解的)st ability 注 润滑油中的内阻力大小是用黏度来表示的。B

64. Start the turning gear, and with some one hand-operating the cylinder lubricators at regular intervals, and with the indicator cocks ____,and with the control gear in the ____ position, give the engine at least one complete turn.

A.open; “stop” B.closed; “stop” C. open; “start” D.closed; “start” 注 启动盘车机，定期手摇气缸油注油器，打开示功阀，控制机构在停车位置，对主机盘车至少一圈。A

65. The lubrication to the cylinders affected by the fire must be ____ to prevent seizure and all scavenge drains must be ____ to prevent the discharge of sparks and burning oil from the drains into the engine room

A.decreased; opened B.decreased; shut

C.increased; opened D.increased; shut

注 为了防止咬缸，发生扫气着火的气缸应该加大气缸油量，并且为防止火星和燃烧的油从放残口进入机舱，所有扫气放残口须关闭。D

66. One characteristic of a lubricating oil adversely affecting the result of centrifuging is ____.

A.high TBN value B.low oil floc point

C.low oil demulsibility D.low oil neutralization number 注 滑油比较低的抗乳化性对其分离是不利的。C

67. Which of the following characteristic of lube 训helps to reduce the amount of deposits in the piston ring belt during the combustion process in a diesel engine?

A.Low viscosity index. B.Low carbon forming tendencies.

C.High film strength. D.High non-corrosive qualities

注 滑油的低结炭性能有助于减少柴油机在燃烧过程中活塞环带沉积物的形成。B

68. Most large, low-speed, main propulsion diesel engines use duplex lube oil strainer to ____.

A.decrease the time required between cleanings

B.removes all large and small foreign objects

C.ensure a positive flow of oil at all times

D.ensure that all lube oil has been treated twice

注 多数大型低速主机使用双联滑油滤器, 这样可以使滑油在任何时候都正常工作。C

69. Which of the following statements concerning the lubrication of diesel propulsion engines used in vessels over 300 gross tons is most accurate?

A.Lubrication systems using engine driven lube oil pumps do not require any additional independent arrangement when such arrangements have been proven reliable.

B. The use of engine driven pre-lube pumps is permitted on vessels with propulsion systems developing less than 500 shaft horsepower.

C. When forced lubrication is used for propulsion engines, one independently driven stand-by pumps is to be provided in addition to the necessary pumps for normal operation.

D.Lubrication systems where two oil coolers are fitted require a minimum of two temperature control devices which may be actuated by similar sensors.

注 对于300总吨以上的主机润滑，如果采用的是强制润滑，除了正常工作所需泵外，应该备有一台独立驱动的滑油泵。C

70. The pressure differential across a diesel engine lube oil system dupIBx filter should be checked to ____.

A.determine the need for filter cleaning

B.measure any change in oil viscosity

C.prevent damage to the filter

D.determine the need for batch filtration

注 柴油机滑油系统滤器前后压差决定滤器是否需要清洗。A

71. The most crucial time for any bearing with regards to lubrication is ____.

A.during low loads B.after proper oil viscosity is reached

C.during starting D.after cleaning filters

注 主轴承润滑的最关键时刻是机器刚启动时。C

72. Main propulsion engine lube oil sumps should be constructed ____.

A.so as to never be integrallube

B.with a sloped bottom

C.only of nonferrous,noncorrosive metals

D.with drain/return lines terminating just above or at the designed normallevel 注 主机滑油泵底部应具有一定的倾斜。D

73. The construction of the main propulsion engine lube oil sump should ____.

A.have no platingjoints of 90

B.retain the lube oil as long as possible before it recirculates through the system

C.provided drain/return lines that are no greater than 24 inches from the pump suction

D.be provided with only a perfectly horizontalbottom

注 主机油底壳的结构应使滑油在油底壳的时间尽可能长，然后再在系统里重新循环。B

74. Diesel engine automated control systems may utilize sensing devices of dual function with sensing ranges providing both alarm and engine shut down capability. Which of the key points would only require an alarm sensor?

A.Lube oil pressure and temperature.

B.jacket water pressure and temperature.

C.Engine over-speed.

D.Lube oil sump level.

注 柴油机自动控制系统可以采用双作用传感设备，即报警和停车，油底壳只需要一个报警传感器。D

75. Which of the listed cylinder liner surface conditions indicates proper lubrication?

A.Dull black appearance B.Bright appearance.

C.Thin layer of lacquer. D.Thick oily film.

注 气缸套表面光亮表明润滑良好。B

76. 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 注 柴油机活塞上的油环工作正常时，应该向缸壁各处充分布油，防止过多滑油进入燃烧室。B

77. How often should the lubricating oil of a diesel engine be changed?

A.After every trip. B.Every 4000 hours.

C.According to manufacturer's instructions. D.Every time they are shutdown 注 柴油机滑油的换油周期应根据厂家说明书而定。C

78. The ability, of lubricating oils to resist viscosity changes during temperature changes is indicated by the ____.

A.american petroleum B.institute number viscosity index number

C.seconds saybolt furol number D.seconds saybolt universal number 注 黏度指数表明，温度变化会影响滑油黏度的变化。B

79. Lubricating oil used in a diesel engine serves to ____.

A.reduce the wear of bearing surfaces B.coolthe bearing surfaces

C.assist in sealing bearing surfaces D.All of the above.

注 柴油机滑油的作用是减摩、冷却、密封等。D

80. One of function of diesel engine lubricating oil is to ____.

A.induce carbon formation on cylinder walls

B.improve fuel penetration in the combustion space

C.form a friction reducing film between mating surfaces

D.lubricate the fuel injection

注 柴油机滑油作用之一是在配合表面之间形成减小摩擦的油膜。C

81. A large, low-speed, crosshead, main propulsion diesel engine using residual fuel oils must have a cylinder oil having a ____.

A.low TBN value B.high alkaline reserve

C.low flash point D.high pour point

注 大型低速十字头式主机烧重油时，应该使用碱值较高的气缸油。B

82. A lube oil filter can be used to remove most contaminants from lube oil. A

contaminant which will remain in the lube oil after filtering is ____.

A.abrasive B.fuel oil C.sediment(沉淀物) D.impurities

注 滑油滤器能去除滑油中绝大多数污染物。滑油经过净化后仍残留的污染物是燃油。B

83. Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because ____.

A.bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversed

B.bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversed

C.the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine

D.two-stoke/cycle diesel engines require more complicated lubrication piping 注 四冲程柴油机与二冲程柴油机相比较，主轴承的润滑更容易一些，因为前者轴承压力是连续翻转（交替）的。A

84. In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines,____.

A.wide compression rmgs 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

注 二冲程柴油机为了防止滑油进入进气口，活塞裙下部应安装油环。D

85.The main reason for the use of cylinder oil is to____.

A. lubricate the piston rings and liner

B.Cool the piston and liner

C.Improve combustion efficiency

D.Protect the jacket

注 汽缸油使用用来润滑活塞环和缸套的。 A

86. On most modem diesel engines, the main and connecting rod bearings receive their lubricating oil by ____.

A.banjo feed(放射管润滑) B.splash feed(飞溅润滑)

C.gravity feed(重力润滑) D.pressure feed(压力润滑)

注 绝大多数现代柴油机，通常都采用压力润滑系统向主轴承和连杆轴承供油。D

87. Main engines as well as auxiliary engines operating on heavy fuel should have continuous ____ on the lubricating oil, either according to the bypass or batch principles.

A.filtering B.centrifuging C.depositing D.operating

注 主机还有辅机在用重油运行时，按照旁通循环或分批处理原则，应对滑油不断地离心分离。

88. For a main diesel engine the lube oil in the bearings is drawn from ____,usually located in the bedplate.

A.a gravity tank(重力柜) B.a sump

C.a vessel D.a bottle

注 对于主机，主轴承的滑油（机油、曲柄箱油）从油底壳吸入，油底壳往往位于机座底下。B

89. Lubricating oil is supplied to the crank-pin bearings in a marine diesel engine by ____.

A.intemal crankshaft passages B.immersion(沉浸)in oil

C.splash lubrication D.inject,ion lubrication

注 在船用柴油机中，一般通过曲轴内部的油槽向曲柄销轴承供油。A

90.The main element of the cylinder wear is of a______.

A.friction nature

B.Corrosive nature

C.Melt nature

D.Neutralizing nature

注 气缸磨损的主要因素是自然腐蚀 B