To reduce the weight of the reciprocating parts, pistons of high-speed engines are made considerably shorterThis results in __________.A.less piston slap and quieter runningB.increased crankshaft bearing wearC.slightly greater piston wearD.decreased side

题目

To reduce the weight of the reciprocating parts, pistons of high-speed engines are made considerably shorterThis results in __________.

A.less piston slap and quieter running

B.increased crankshaft bearing wear

C.slightly greater piston wear

D.decreased side pressures

相似考题

1.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 improversB.Pour point improversC.InhibitorsD.Foam suppressors(抑制物)

2.Addition of weight above the center of gravity of a vessel will ALWAYS ______.A.reduce initial stabilityB.increase righting momentsC.increase GMD.cannot be determined

3.Addition of weight to a vessel will ALWAYS ______.A.reduce reserve buoyancyB.increase righting momentsC.increase GMD.All of the above

4.The greatest strain，when lifting a load with the jumbo purchase，is on ______．A.all of the parts，dividing the load equallyB.the hauling part because it must absorb the frictional losses of all the sheavesC.the parts in the movable blockD.the standing part because it is directly connected to the weight

参考答案和解析
正确答案：C
更多“To reduce the weight of the reciprocating parts, pistons of high－speed engines are made co ”相关问题

  • 第1题：

    In order to reduce your wake in a narrow channel you should ______.

    A.apply enough rudder to counter the effect of the current

    B.change your course to a zigzag course

    C.reduce your speed

    D.shift the weight to the stern


    正确答案：C
    在狭水道中为了减少你船的伴流你应减速。

  • 第2题：

    单选题
    （）are increasingly used as main engine on merchant vessels, because they have a high Hp/Weight ratio.
    A

    Slow speed diesel engines

    B

    Medium-speed diesel engines

    C

    Steam engines

    D

    Gasoline engines


    正确答案： C
    解析： 暂无解析

  • 第3题：

    单选题
    Smaller engines can be made more rigid than large ones and may not have （）.
    A

    connecting rods

    B

    crankshaft

    C

    crankcase

    D

    through bolts


    正确答案： D
    解析： 暂无解析

  • 第4题：

    单选题
    The main purpose of warming the parts of the main engine is （）
    A

    to reduce heat stress

    B

    to reduce low temperature corrosion

    C

    to improve firing and starting performance

    D

    fuel saving


    正确答案： C
    解析： 暂无解析

  • 第5题：

    单选题
    The main moving parts of a diesel engine consist of the （） and the pistons.
    A

    bedplate, connecting rods

    B

    crankshaft, the connecting rods

    C

    frames, crossheads

    D

    crankshaft, the cylinder


    正确答案： B
    解析： 暂无解析

  • 第6题：

    单选题
    The primary duty of lube oil is to reduce （） between the working parts of an engine.
    A

    power output

    B

    friction and wear

    C

    indicated pressure

    D

    rated horsepower


    正确答案： B
    解析： 暂无解析

  • 第7题：

    单选题
    Due to （） action of pistons some relative motion between parts in contact in the coolant supply and return system must occur.
    A

    reciprocating

    B

    rotating

    C

    running

    D

    removing


    正确答案： B
    解析： 暂无解析

  • 第8题：

    单选题
    One method of constructing large marine diesel engines and reducing the total engine frame weight is through （）.
    A

    casting interlocking components

    B

    welding plates to form sections for assembly

    C

    forging integral components

    D

    case hardening integral components


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    （）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 crosshead type；crossheads

    B

    High speed；the cylinders

    C

    Large crosshead type；the cylinders

    D

    Four-stroke；pistons and cylinders


    正确答案： D
    解析： 暂无解析

  • 第10题：

    单选题
    Cast iron pistons used in large propulsion diesel engines are constructed with （）
    A

    not taper what so ever

    B

    the skirt being tapered and smaller than the crown

    C

    the skirt being tapered and larger than the crown

    D

    the crown being tapered and smaller than the skirt


    正确答案： B
    解析： 暂无解析

  • 第11题：

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

    Flash point improvers

    B

    Pour point improvers

    C

    Inhibitors

    D

    Foam suppressors


    正确答案： C
    解析： 暂无解析

  • 第12题：

    单选题
    Moving parts of machines and motor vehicles have to be _____ regularly to reduce friction.
    A

    lubricated

    B

    fabricated

    C

    embedded

    D

    dictated


    正确答案： B
    解析：
    句意：机器和机动车的运动零件要定期润滑以减少摩擦。lubricate润滑。fabricate编造。embed镶嵌。dictate口述。

  • 第13题：

    单选题
    Smaller engines can be made more rigid than large ones and may not have （）.
    A

    through bolts

    B

    turbo-chargers

    C

    bed plates

    D

    columns


    正确答案： D
    解析： 暂无解析

  • 第14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15题：

    单选题
    An advantage of aluminum pistons, when compared to cast iron pistons is （）.
    A

    greater high temperature strength

    B

    better heat conductivity

    C

    greater weight per cubic inch

    D

    increased resistance to wear


    正确答案： A
    解析： 暂无解析

  • 第16题：

    单选题
    In order to control thermal stresses, some types of modern engines use pistons with（）
    A

    heavy wall and intensive cooling

    B

    heavy wall and no cooling

    C

    thin wall and no cooling

    D

    thin wall and intensive cooling


    正确答案： C
    解析： 暂无解析

  • 第17题：

    单选题
    To reduce the weight of the reciprocating parts, pistons of high-speed engines are made considerably shorterThis results in （）
    A

    less piston slap and quieter running

    B

    increased crankshaft bearing wear

    C

    slightly greater piston wear

    D

    decreased side pressures


    正确答案： A
    解析： 暂无解析

  • 第18题：

    单选题
    Pistons may be made in （） in order to keep the weight down for balancing purposes at high speed.
    A

    cast iron

    B

    forged steel

    C

    stainless steel

    D

    aluminum alloy


    正确答案： C
    解析： 暂无解析

  • 第19题：

    单选题
    The greatest strain，when lifting a load with the jumbo purchase，is on（）.
    A

    all of the parts，dividing the load equally

    B

    the hauling part because it must absorb the frictional losses of all the sheaves

    C

    the parts in the movable block

    D

    the standing part because it is directly connected to the weight


    正确答案： A
    解析： 暂无解析

  • 第20题：

    单选题
    On engines having oil cooled pistons the lubricating oil pre-heater must be put into operation and the rate of heating so （） that the temperature of the piston cooling oil returns are 32℃ to 35℃ over a period of at least two hours.
    A

    slow

    B

    quick

    C

    arranged

    D

    high


    正确答案： C
    解析： 暂无解析

  • 第21题：

    单选题
    Modern engines （） exhaust gas driven turbo-chargers to supply pressurized fresh air for scavenging and supercharging.
    A

    are made of

    B

    are made from

    C

    make use of

    D

    are used to


    正确答案： A
    解析： 暂无解析

  • 第22题：

    单选题
    Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.
    A

    lead

    B

    forged steel

    C

    alloy steel

    D

    aluminum alloy


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    Shifting weight aft in heavy weather will reduce the tendency to yaw，but may increase the tendency to（）.
    A

    be pooped

    B

    pitchpole

    C

    broach

    D

    squat


    正确答案： C
    解析： 暂无解析

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