Wear occurring at the tips of the reduction gear teeth is usually the result of ______.A.surface fatigueB.fretting corrosionC.heavy overloadingD.gear misalignment

题目

Wear occurring at the tips of the reduction gear teeth is usually the result of ______.

A.surface fatigue

B.fretting corrosion

C.heavy overloading

D.gear misalignment

相似考题

1.Combustion knock occurring in a diesel engine can be caused by _____.A.low coolant temperatureB.insufficient fuelC.high ambient temperatureD.carbon buildup on the injector tips

2.One of the most common causes of reduction gear failure is gear wear caused by scoring as a result ofA.surface fatigue of the gearsB.an inadequate lube oil filmC.plastic flow of the gearsD.fretting corrosion from water

3.Pitted reduction gear teeth having a deep blue color with evidence of overheating have been operated with _______.A.excessive speedB.improper warm-upC.extreme misalignmentD.inadequate lubrication

4.When transmitted by a reduction gear, diesel engine speed is reduced and the torque available for workA.remains the sameB.is reducedC.is increasedD.is eliminated

更多“Wear occurring at the tips of the reduction gear teeth is usually the result of ______.A.s ”相关问题

  • 第1题：

    第二组：Magnetic pickup (MPU) sensors are devices which can be used in conjunction with electronic control modules for monitoring of parameters such as speed, direction of rotation and a variety of alarm conditions. MPU sensors are available in various sizes and types. Following are some guidelines for their selection on industrial engines. MPUs are located near a flywheel, camshaft or other type of gear with rotation relative to engine speed. The passing of the gear teeth through the MPU tip (pole) generates a voltage and frequency. This frequency is converted to a speed reference by a control module. It should be noted here that most MPUs will develop similar signals. However, the magnitude and strength of the signal is dependent on the size of the sensor in relation to the gear teeth, the clearance between the pole piece and the gear teeth, and various other factors. As a general rule of thumb, the following standards should be met:

    ①Dimension of tooth top surface should be equal to or more than the pole piece diameter.

    ②Tooth height should be equal to, or more than the space between teeth.

    ③The space between teeth should be approximately three times the pole piece diameter.

    ④Air gap (clearance) between tooth and pole piece should be between 0.015" to 0.030". MPUs

    normally have 3/8", 5/8" threads and 2", 3" and 4" lengths. Determining which size is appropriate

    depends on the space available for installation, the availability of pre-drilled holes and consideration to

    those rules mentioned above. In most cases, these will be the only factors affecting the selcetion of a

    MPU.

    MPUs can be used to ____.①sense speed ②supply alarm ③sense direction of rotation.

    A.①②

    B.②③

    C.①③

    D.①②③


    正确答案：D

  • 第2题：

    Chafing gear ______.

    A.reduces and prevents corrosion of standing rigging

    B.prevents corrosion of running rigging

    C.reduces and prevents wear caused by the rubbing of one object against another

    D.protects the body against extreme cold


    正确答案：C

  • 第3题：

    I rarely wear a raincoat because I spend most of my time in a car.

    A:normally
    B:seldom
    C:frequently
    D:usually

    答案：B
    解析：

  • 第4题：

    单选题
    The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.
    A

    sudden evaporation of wax crystals in the lubricant

    B

    sudden evaporation of entrapped air in the lubricant

    C

    release of refrigerant from the oil/refrigerant mixture

    D

    release of dissolved lubricant from the refrigerant


    正确答案： B
    解析： 暂无解析

  • 第5题：

    单选题
    A magnetic strainer is used in the diesel engine reduction gear oil system to remove small particles of（）.
    A

    water

    B

    babbitt

    C

    iron or steel

    D

    acids


    正确答案： D
    解析： 暂无解析

  • 第6题：

    单选题
    Where are the test certificates，for wire rope used as cargo runners，and loose gear certificates usually maintained? （）
    A

    With the Cargo Gear Register on the ship

    B

    In the Official Log

    C

    At the Coast Guard Marine Safety Office with the vessel's inspection records

    D

    At the central records center of the agency testing the cargo gear


    正确答案： B
    解析： 暂无解析

  • 第7题：

    单选题
    Positive displacement, helical gear pumps are well suited for pumping oil because （）
    A

    stuffing boxes eliminate the leakage problems usually associated with other gear pumps

    B

    it is not necessary to closely maintain design clearances with this pump

    C

    they are essentially self-priming and produce a high suction lift

    D

    these pumps are designed with extreme tooth angled


    正确答案： A
    解析： 暂无解析

  • 第8题：

    单选题
    To absorb the wear resulting from impeller rotation and abrasives in the liquid, a centrifugal pump is usually fitted with （）.
    A

    lantern rings

    B

    bearings

    C

    easing volutes

    D

    wearing rings


    正确答案： D
    解析： 暂无解析

  • 第9题：

    单选题
    Some medium and high-speed diesel engines require reduction gear units to provide a useful propeller speedIn most reduction gears, the bull gear（）
    A

    must churn the oil in the sump

    B

    is connected to the propeller shaft

    C

    is driven at the highest RPM

    D

    compensates for alignment variations between the engine and pinion gear


    正确答案： B
    解析： 暂无解析

  • 第10题：

    单选题
    To guarantee that a reduction gear bearing is receiving proper oil supply, you should check the （）
    A

    lube oil temperature at the cooler outlet

    B

    lube oil strainer magnets bearing

    C

    lube oil temperature

    D

    lube oil pressure to the bearing


    正确答案： A
    解析： 暂无解析

  • 第11题：

    单选题
    Pitted reduction gear teeth having a deep blue color with evidence of overheating have been operated with （）
    A

    excessive speed

    B

    improper warm-up

    C

    extreme misalignment

    D

    inadequate lubrication


    正确答案： A
    解析： 暂无解析

  • 第12题：

    单选题
    In an electro-hydraulic steering gear, any change in relative position between the synchronous receiver and the follow-up gear will result in（）
    A

    the pump going to full stroke

    B

    closing of the six-way valve

    C

    driving the rams up against the stops

    D

    a corresponding slowing or increasing of the pumped flow rate


    正确答案： B
    解析： 暂无解析

  • 第13题：

    Brides usually wear white wedding dresses，because white______ purity．

    A．stands for

    B．stands out

    C．stands up

    D．stands by


    正确答案：A
    stand for“代表”；stand out“突出，出色，支撑住”；stand up“站起”；standby“遵守袖手旁观”。

  • 第14题：

    Usually the Charterer has to redeliver the ship in the same good order ______ when delivered，fair wear and tear excepted．

    A.in

    B.by

    C.on

    D.as


    正确答案：D

  • 第15题：

    单选题
    What is the function of the thrust bearing?（）
    A

    Prevents lateral movement of the slow speed gear

    B

    Transmits propeller thrust to the hull

    C

    Keeps spring bearings in line

    D

    Prevents main reduction gear axial movement


    正确答案： D
    解析： 暂无解析

  • 第16题：

    单选题
    When transmitted by a reduction gear, diesel engine speed is reduced and the torque available for work （）
    A

    remains the same

    B

    is reduced

    C

    is increased

    D

    is eliminated


    正确答案： C
    解析： 暂无解析

  • 第17题：

    单选题
    Proper operation of the main engine reduction gear set requires the operation to monitor （）
    A

    the sump oil level

    B

    oil flow sight glasses

    C

    bearing temperatures

    D

    all of the above


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    On your vessel，a wire rope for the cargo gear shows signs of excessive wear and must be replaced. In ordering a new wire for this 10-ton boom，what safety factor should you use?（）
    A

    Three

    B

    Five

    C

    Six

    D

    Seven


    正确答案： A
    解析： 暂无解析

  • 第19题：

    单选题
    Chafing gear（）.
    A

    reduces and prevents corrosion of standing rigging

    B

    prevents corrosion of running rigging

    C

    reduces and prevents wear caused by the rubbing of one object against another

    D

    protects the body against extreme cold


    正确答案： B
    解析： 暂无解析

  • 第20题：

    单选题
    Pitting in the area close to the pitch line and on the same end of each gear tooth of a reduction gear unit would be caused by （）
    A

    corrosion on the gears

    B

    excessive gear speed

    C

    dirt in the oil

    D

    misalignment of the gears


    正确答案： A
    解析： 暂无解析

  • 第21题：

    单选题
    Combustion knock occurring in a diesel engine can be caused by （）
    A

    low coolant temperature

    B

    insufficient fuel

    C

    high ambient temperature

    D

    carbon buildup on the injector tips


    正确答案： C
    解析： 暂无解析

  • 第22题：

    单选题
    Wear occurring at the tips of the reduction gear teeth is usually the result of （）.
    A

    surface fatigue

    B

    fretting corrosion

    C

    heavy overloading

    D

    gear misalignment


    正确答案： D
    解析： 暂无解析

  • 第23题：

    单选题
    The majority of cargo gear breakdowns are a result of（）.
    A

    Guy failures

    B

    Topping lift failures

    C

    Bending of the boom from compression

    D

    Gooseneck failure


    正确答案： A
    解析： 暂无解析

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