网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)
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


参考答案

参考解析
解析: 暂无解析
更多 “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;orB neither;norC such;thatD so;that” 相关考题
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?

考题 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 theA.crossheadB.crankpinC.crank journalD.gudgeon pin

考题 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

考题 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

考题 when the fuel is provided by the supplier ,what specifications of the oil can you get from the supplier receipt ?

考题 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

考题 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

考题 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!

考题 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

考题 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?()A The six-way valve opensB The steering service pump motor is stoppedC The follow-up gear takes the pump off strokeD The cylinder relief valves bypass oil to the suction side the pump

考题 单选题A dirty lube oil strainer can result in()A crankcaseB low lube oil temperatureC excessive oil consumptionD low bearing oil pressure

考题 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 crossheadB crankpinC crank journalD gudgeon pin

考题 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 pipesB large boreC drilled passageD tied rod

考题 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?()A Decreased connecting rod bearing clearanceB Increased connecting rod bearing clearanceC Decreased compression ratioD Increased compression ratio

考题 单选题When discharging an oil cargo,the first consideration is to().A get the bow upB discharge from the wings firstC discharge from the centerline tanks firstD discharge from amidships first

考题 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?()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

考题 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?()A The overall condition of the bearing surface should be examinedB The shaft liner should be inspected for cracks and tested to insure a tight fitC The stern tube should be tested for cracks with dye penetrantD all of above

考题 单选题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

考题 单选题When an oil fire has been extinguished, the surface of the oil should be kept covered with foam to prevent ().A air from contacting the oil vaporsB permitting re-ignition boiling of the heated oilC spontaneous combustion below the oil surfaceD toxic fumes from escaping to the surface

考题 单选题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

考题 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?()A the cross-headB the pumpsC the shellD the load

考题 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;orB neither;norC such;thatD so;that

考题 单选题The oil in a cargo winch gear box should be sampled periodically to ().A prevent the gear box from leakingB prevent the oil from becoming inflammableC make sure it has not become contaminatedD make sure the motor bearings are lubricated

考题 单选题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 telemotor cylinders each watch

考题 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 outletB lube oil strainer magnets bearingC lube oil temperatureD lube oil pressure to the bearing

考题 单选题High lube oil temperatures developing in a diesel engine can result from()A high oil pressureB excessive bearing end playC plugged oil control ringsD engine overload

考题 单选题Lubricating oil used in a diesel engine serves to()A reduce the wear of bearing surfacesB cool the bearing surfacesC assist in sealing bearing surfacesD all of the above

考题 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 pipesB the main and crankpin bearingsC thrust and intermediate bearingsD stern tube and thrust bearings