单选题Abnormal crankpin bearing and piston skirt surface wear indicate（）A a restricted air intakeB a clogged connecting rod oil passageC incorrect connecting rod alignmentD high cylinder firing temperatures

题目
单选题
Abnormal crankpin bearing and piston skirt surface wear indicate（）
A

a restricted air intake

B

a clogged connecting rod oil passage

C

incorrect connecting rod alignment

D

high cylinder firing temperatures

相似考题

1.In an engine with a pot-shaped piston, some lubricating oil from the main bearing will pass along a drilled passage in the crankshaft to the bottom end bearing and then up a connection rod to theA.crossheadB.crankpinC.crank journalD.gudgeon pin

2.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 runningB increased crankshaft bearing wearC slightly greater piston wearD decreased side pressures

3.单选题In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines, （）A wide compression rings are usedB oil rings are located above the pistonC chromium plating is used on all piston ringsD oil rings are located near the bottom of the piston skirt

4.单选题Bearing knocks are likely to occur from （）.A less clearanceB dirty lube oilC overloadD bearing wear

更多“Abnormal crankpin bearing and piston skirt surface wear indi”相关问题

  • 第1题：

    单选题
    A well-lubricated bearing surface always appears（）
    A

    well knurled

    B

    slightly streaked

    C

    lightly glazed

    D

    highly polished


    正确答案： A
    解析： 暂无解析

  • 第2题：

    单选题
    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 andthen up a connection rod to the gudgeon pin.
    A

    telescopic pipes

    B

    large bore

    C

    drilled passage

    D

    tied rod


    正确答案： C
    解析： 暂无解析

  • 第3题：

    单选题
    The diameter of a piston is usually less at the crown than at the skirt, in order to （）.
    A

    facilitate the installation of piston rings

    B

    allow for the expansion of the piston during operation

    C

    prevent crankcase vapors from entering the combustion chamber

    D

    reduce wearing of the upper cylinder liner


    正确答案： A
    解析： 暂无解析

  • 第4题：

    单选题
    Oil 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


    正确答案： A
    解析： 暂无解析

  • 第5题：

    单选题
    One method of determining crankshaft misalignment is by（）
    A

    laying a straight edge across the crank webs at the crankpin and measuring the distance to the crankpin in two places

    B

    measuring the crank drop on either side of each crank throw while the crankshaft is slowly rotated through one revolution

    C

    rotating the crankshaft through one revolution, pausing each 90oof rotation to measure bearing clearances, top and bottom

    D

    taking micrometer reading between the crank cheeks opposite the crankpin every 90°of crank angle rotation


    正确答案： A
    解析： 暂无解析

  • 第6题：

    单选题
    The gudgeon pin is carried in （） in the piston skirt.
    A

    the bearing

    B

    the crosshead

    C

    bosses

    D

    bridges


    正确答案： C
    解析： 暂无解析

  • 第7题：

    单选题
    An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer’s vessel. Which of the following is NOT a characteristic of indirect echoes?（）.
    A

    Their bearing is almost constant，even when the true bearing of the contact changes appreciably

    B

    They always appear on a bearing of 90°from the true bearing of the contact

    C

    The indirect echoes usually appear in shadow sectors

    D

    When plotted，their movements are usually abnormal


    正确答案： B
    解析： 暂无解析

  • 第8题：

    单选题
    Why is the ring belt narrower in diameter than the skirt of a piston designed for a diesel engine?（）
    A

    To allow for greater expansion due to higher operating temperature

    B

    To seal the cylinder against leakage of combustion gases

    C

    To provide an additional surface for oil cooling

    D

    To provide an additional strength for the crown and lower structure


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    Which term describes piston pins having bearing surfaces in both the piston bosses and connecting rod eye?（）
    A

    Stationary

    B

    Full floating

    C

    Semi-floating

    D

    Free rolling


    正确答案： A
    解析： 暂无解析

  • 第10题：

    单选题
    In a diesel engine, excessive cylinder liner wear will cause （） Ⅰ.increased blow-by Ⅱ.wear between the piston ring and groove
    A

    Ⅰonly is correct

    B

    Ⅱ only is correct

    C

    both Ⅰ and Ⅱ are correct

    D

    neither Ⅰ or Ⅱ are correct


    正确答案： D
    解析： 暂无解析

  • 第11题：

    单选题
    Lubricating oil used in a diesel engine serves to（）
    A

    reduce the wear of bearing surfaces

    B

    cool the bearing surfaces

    C

    assist in sealing bearing surfaces

    D

    all of the above


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    Cold clearances between the skirt of an aluminum piston and the cylinder liner is about （）
    A

    twice as large as with a cast iron piston

    B

    the same size as with a cast iron piston

    C

    half as large as with a cast iron piston

    D

    the same size as the crown of an aluminum piston


    正确答案： C
    解析： 暂无解析

  • 第13题：

    单选题
    In an engine with a pot-shaped piston, some lubricating oil from the main bearing will pass along a drilled passage in the crankshaft to the bottom end bearing and then up a connection rod to the （）.
    A

    crosshead

    B

    crankpin

    C

    crank journal

    D

    gudgeon pin


    正确答案： D
    解析： 暂无解析

  • 第14题：

    单选题
    Why are some diesel engine cylinder liners plated on the wearing surface with porous chromium?（）
    A

    The chromium will not wear out the piston rings

    B

    The chromium strengthens the liners in the way of the scavenging air ports

    C

    Chromium eliminates the need for oil scraper rings

    D

    Pores in the plating aid in maintaining the lube oil film


    正确答案： C
    解析： 暂无解析

  • 第15题：

    单选题
    Which of the listed conditions can cause lacquer to be deposited on a piston skirt?（）
    A

    High sulphur content fuel

    B

    High lube oil temperatures

    C

    High vanadium content fuel

    D

    Excessive piston slap


    正确答案： B
    解析： 暂无解析

  • 第16题：

    单选题
    Small crack in the crankshaft bearing surface of a diesel engine are an indication of（）
    A

    corrosion fretting

    B

    insufficient lubrication

    C

    abnormal wear

    D

    fatigue failure


    正确答案： D
    解析： 暂无解析

  • 第17题：

    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


    正确答案： C
    解析： 暂无解析

  • 第18题：

    单选题
    In a large, low-speed diesel engine the clearance between the piston crown and cylinder head is found to be excessiveIn order to correct for this, you should（）
    A

    build up the piston crown by metal spraying

    B

    build up the cylinder head by metal spraying

    C

    insert shims between the crankpin bearing box and the connecting rod foot

    D

    install a thinner head gasket


    正确答案： A
    解析： 暂无解析

  • 第19题：

    单选题
    In an auxiliary diesel engine, the reason for knurling the piston skirt is to（）
    A

    improve skirt lubrication

    B

    allow for expansion

    C

    transmit forces evenly

    D

    improve the piston seal


    正确答案： D
    解析： 暂无解析

  • 第20题：

    单选题
    Which of the following statements concerning cylinder liner wear is true?（）
    A

    Liner wear is distributed equally between the upper and lower portions of the cylinder

    B

    Excessive liner wear causes wear between piston ring and groove

    C

    Excessive, but uniform liner wear will not cause wear between piston ring and groove

    D

    Liner wear is normally greatest in the middle of the cylinder


    正确答案： B
    解析： 暂无解析

  • 第21题：

    单选题
    While inspecting the main bearings on a diesel engine you find impregnated dirt and scratches in the bearing surface you would, therefore, suspect that （）
    A

    the bearing had been overheated

    B

    water was present in the oil

    C

    the lube oil was not being properly filtered

    D

    the maximum allowable bearing pressure had been exceeded


    正确答案： D
    解析： 暂无解析

  • 第22题：

    单选题
    Ring groove inserts are occasionally used on aluminum alloy piston to（）
    A

    reduce the ring groove wear rate

    B

    seal against crankcase vapors

    C

    lessen the wear on aluminum part of the cylinder

    D

    allow for the greater expansion rate of aluminum


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    Just after stopping the engine while the oil is still circulating.Check that uniform oil jets appear from all the oil outlet grooves in the crosshead bearing lower shell and the guide shoes.The oil flow from （） must be compared from unit; there should be a similarity in the flow patterns.
    A

    the piston cooling oil return pipes

    B

    the main and crankpin bearings

    C

    thrust and intermediate bearings

    D

    stern tube and thrust bearings


    正确答案： D
    解析： 暂无解析

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