单选题When the bearing becomes dry from lack of oil, the motor shaft may heat to （）an extent （） it welds itself to the bearing.Aeither；orBneither；norCsuch；thatDso；that
单选题
When the bearing becomes dry from lack of oil, the motor shaft may heat to （）an extent （） it welds itself to the bearing.
A
either；or
B
neither；nor
C
such；that
D
so；that
参考解析
解析：
暂无解析
相关考题：
Have you ever served the auxiliary engine to combustion heavy oil? What should be borne in mind when transferring oil; from heavy oil to light oil?
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
Lubrication for the main reduction gears used with diesel engines is usually supplied byA.oil from the main engine sumpB.an independent lube oil systemC.the stern bearing head tankD.the stem bearing sump tank
When the tail-shaft is drawn from a vessel in dry-dock, which of the following inspections is required to be carried out?A.The propeller hub taper and shaft keyway should be inspected for cracks or corrosionB.The stern bearing alignment with the stern frame should be checkedC.The interior of the stern tube should be inspected for leaksD.The shaft liner should be removed and inspected for cracks
when the fuel is provided by the supplier ,what specifications of the oil can you get from the supplier receipt ?
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
When the steering gear is in operation, you should ______.A.check hydraulic oil levels every hourB.check the rams for overheatingC.check for excessive oil leakage from ramsD.drain water from tele-motor cylinders each watch
材料：Spark erosion is caused by a voltage discharge between the main bearing and journal surface. The cause of the potential is the development of a galvanic element between the ship’s hull, sea water, and the propeller shaft/crankshaft.The oil film acts as a dielectric. The puncture voltage in the bearing depends on the thickness of the oil film. With increasing engine ratings, the specific load in the main bearing is increased. his will reduce the oil film thickness, and enable the discharge to take place at a lower voltage level.Since the hydrodynamic oil film thickness varies through a rotation cycle, the discharge will take place at roughly the same instant during each rotation cycle, i.e. when the film thickness is at its minimum. The roughening will accordingly be concentrated in certain areas on the journal surface. In the early stages, the roughened areas can resemble pitting erosion. but later, as the roughness increases, the small craters will scrape off and pick up white metal-hence the silvery white appearance.Therefore, to ensure protection against spark erosion, the potential level must be kept at maximum 80 mV, which is feasible today with a high efficiency earthing device. If an earthing device is installed, its effectiveness must be checked regularly. Spark erosion is only observed in main bearings and main bearing journals.问题：According to the paragraph one, a voltage between the main bearing and journal surface is produced by______.A.propeller rotationB.leakage from M/E electric control unitC.a galvanic elementD.friction between the main bearing and journal surface______engine ratings increase, the hydrodynamic oil film between the main bearing and journal surface is______.A.The lower/thinnerB.The higher/the thickerC.The lower/thickerD.The higher/thinnerWhen will the spark erosion take place on the journal surface during each rotation cycle?A.when the film thickness is at its minimumB.when the film thickness is at its maximumC.when the engine is on its compression strokeD.when the engine is on its exhaust strokeDuring the engine room watch keeping, which equipment must be noted to ensure protection against spark erosion?A.the antifouling plantB.the earthing deviceC.the main engine electric heating coilsD.the shaft generator请帮忙给出每个问题的正确答案和分析，谢谢！
A portable dry chemical fire extinguisher discharges by ______.A.gravity when the extinguisher is turned upside downB.pressure from a small CO2 cartridge on the extinguisherC.air pressure from the hand pump attached to the extinguisherD.pressure from the reaction when water is mixed with the chemical
单选题When the helm demands a 20°right rudder movement from an electro-hydraulic steering gear, which of the listed actions will be the FIRST action to happen when this rudder position is attained?（）AThe six-way valve opensBThe steering service pump motor is stoppedCThe follow-up gear takes the pump off strokeDThe cylinder relief valves bypass oil to the suction side the pump
单选题A dirty lube oil strainer can result in（）AcrankcaseBlow lube oil temperatureCexcessive oil consumptionDlow bearing oil pressure
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 （）.AcrossheadBcrankpinCcrank journalDgudgeon pin
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.Atelescopic pipesBlarge boreCdrilled passageDtied rod
单选题Which of the following operating conditions can occur when shims are removed from the joint between the foot of a marine type diesel engine connecting rod and the bearing box?（）ADecreased connecting rod bearing clearanceBIncreased connecting rod bearing clearanceCDecreased compression ratioDIncreased compression ratio
单选题When discharging an oil cargo，the first consideration is to（）.Aget the bow upBdischarge from the wings firstCdischarge from the centerline tanks firstDdischarge from amidships first
单选题When the tail-shaft is drawn from a vessel in dry-dock, which of the following inspections is required to be carried out?（）AThe propeller hub taper and shaft keyway should be inspected for cracks or corrosionBThe stern bearing alignment with the stern frame should be checkedCThe interior of the stern tube should be inspected for leaksDThe shaft liner should be removed and inspected
单选题A vessel has been equipped with an oil lubricated stern bearing and is undergoing a routine dry-dock.Which of the following inspection should be made when the tail-shaft has been drawn?（）AThe overall condition of the bearing surface should be examinedBThe shaft liner should be inspected for cracks and tested to insure a tight fitCThe stern tube should be tested for cracks with dye penetrantDall of above
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When an oil fire has been extinguished, the surface of the oil should be kept covered with foam to prevent （）.Aair from contacting the oil vaporsBpermitting re-ignition boiling of the heated oilCspontaneous combustion below the oil surfaceDtoxic fumes from escaping to the surface
单选题A portable dry chemical fire extinguisher discharges by（）.Agravity when the extinguisher is turned upside downBpressure from a small CO2 cartridge on the extinguisherCair pressure from the hand pump attached to the extinguisherDpressure from the reaction when water is mixed with the chemical
单选题The pumps press oil into the cross-head bearing gap when the load on the shell is at its lowest What is the meaning of “its” in the sentence above?（）Athe cross-headBthe pumpsCthe shellDthe load
单选题The oil in a cargo winch gear box should be sampled periodically to （）.Aprevent the gear box from leakingBprevent the oil from becoming inflammableCmake sure it has not become contaminatedDmake sure the motor bearings are lubricated
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To guarantee that a reduction gear bearing is receiving proper oil supply, you should check the （）Alube oil temperature at the cooler outletBlube oil strainer magnets bearingClube oil temperatureDlube oil pressure to the bearing
单选题High lube oil temperatures developing in a diesel engine can result from（）Ahigh oil pressureBexcessive bearing end playCplugged oil control ringsDengine overload
单选题Lubricating oil used in a diesel engine serves to（）Areduce the wear of bearing surfacesBcool the bearing surfacesCassist in sealing bearing surfacesDall of the above
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.Athe piston cooling oil return pipesBthe main and crankpin bearingsCthrust and intermediate bearingsDstern tube and thrust bearings