Leakage of hydraulic fluid from around the shaft of a hydraulic motor may be caused by ______.A.permanent loss of pump suctionB.worn shaft sealsC.high level in the oil sumpD.low motor RPM
Leakage of hydraulic fluid from around the shaft of a hydraulic motor may be caused by ______.
A.permanent loss of pump suction
B.worn shaft seals
C.high level in the oil sump
D.low motor RPM
相关考题：
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Hydraulic machinery failures are commonly caused by contamination of the hydraulic fluid and ______.A.fluid frictionB.fluid turbulenceC.component misalignmentD.pressure surges
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The major cause of trouble in a mechanical-hydraulic governor is contamination of the hydraulic fluid by ______.A.dirtB.fuel oilC.governor cooling waterD.fuel oil tar(焦油)
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单选题A hydraulic accumulator aboard a ship is designed to（）.Astore fluid under pressureBact as a fluid reservoirCprovide overpressure reliefDreplenish fluid to a system
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单选题If a hydraulic pump is overheating, the cause may be （）.Aexcessive internal leakage in the pumpBlow discharge pressure and fluid flowCexcessive fluid level in the hydraulic reservoirDoperation of the pump at 100% efficiency
单选题Before doing any work on a hydraulic system equipped with accumulators, you should（）Adrain the accumulators and purge with oxygenBbleed off all stored energy from the accumulators completelyCcharge the accumulators to prevent system energy lossDpump the hydraulic fluid into the accumulators to prevent fluid loss
单选题Air trapped in the hydraulic fluid of a steering system may be indicated by（）Athe steering pumps overspeedingBa jammed open relief valeCa constantly occurring improper rudder responseDexcessive ram pressure
单选题An orifice-check valve placed in a hydraulic system is used to（）Aregulate the fluid flow in either directionBrestrict movement of hydraulic fluid in one direction, but allow free movement in the other directionCallow free movement of hydraulic fluid in both directionsDallow a restricted fluid flow in one direction only
单选题The major cause of trouble in a mechanical-hydraulic governor is contamination of the hydraulic fluid by （）AdirtBfuel oilCgovernor cooling waterDfuel oil tars
单选题Leakage of hydraulic fluid from around the shaft of a hydraulic motor may be caused by（）Apermanent loss of pump suctionBworn shaft sealsChigh level in the oil sumpDlow motor RPM
单选题External and internal leakage in hydraulic systems may be caused by （）.Aunusual vibrationBexcessive worn partsCabnormal pressureDany of the above
单选题When the steering gear is in operation, you should （）.Acheck hydraulic oil levels every hourBcheck the rams for overheatingCcheck for excessive oil leakage from ramsDdrain water from telemotor cylinders each watch
单选题A hydraulic accumulator is designed to（）.Astore fluid under pressureBact as a fluid reservoirCprovide overpressure reliefDreplenish fluid to a system
单选题Hydraulic machinery failures are commonly caused by contamination of the hydraulic fluid and （）.Afluid frictionBfluid turbulenceCcomponent misalignmentDpressure surges
单选题In a shell-and-tube type hydraulic fluid cooler, the amount of heat transferred from the hydraulic fluid to the cooling water depends upon（）Athe temperature of the hydraulic fluidBthe flow rate of the hydraulic fluidCthe temperature of the cooling waterDall of the above
单选题If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.Aa low load on the unitBa clogged pump suction strainerCa blockage in the line between the pump and hydraulic motorDthe hydraulic motor turning too fast
单选题Hydraulic machinery failures are commonly caused by misalignment of the system components and by （）.Ahydraulic fluid contaminationBexcessive fluid frictionCturbulent fluid flowDfluid pressure surges