Diesel engine crankshaft deflection readings are generally taken at four crank positionsGood engineering practice requires the deflection gage or indicator to be（）
A . placed as near the crankpin axis as possible
B . removed each time the crankshaft is repositioned
C . left in place for all four readings
D . reset to zero for all four reading
相似题目
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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
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Today, crankshafts for large 2-stroke crosshead engines are of the （）type.
A . semi-built
B . built-up
C . solid forged
D . individual forged
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A supercharged diesel engine when compared to a similar naturally aspirated diesel engine, will develop an increase in （）
A . ignition lag
B . engine horsepower
C . lube oil system pressure
D . specific fuel consumptio
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The crankshaft receives and transmits the full working power of the engine and is subjected to fluctuating （）.
A . bending stresses弯曲应力
B . torsion stresses扭转应力
C . shear stresses剪应力
D . All of the above
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A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine（）
A . has little or no internal friction
B . has a lower effective compression ratio
C . operates with scavenge air under a positive pressure
D . operates without energy absorbing intake and exhaust stroke
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The crankshaft of diesel engine is supported by （）.
A . tension stretch
B . tie rods
C . through bolts
D . main bearing
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Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the （）.
A、main bearings
B、connecting rod bearings
C、piston pin bushings
D、all of the above
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On a four-stroke diesel engine, when the piston is driven downwards by the expanding gas, it delivers power to the crankshaft through the （）.
A . thrust block
B . sounding rod
C . connecting rod
D . push rod
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Vee-type engines have the connecting rods from two cylinders connected to each （） of the crankshaft.
A . throw
B . web
C . main bearing
D . deflectio
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Diesel engines are considered safer than gasoline engines because（）.
A . they are more heavily built
B . the fuel used is less volatile
C . they can be easily reversed
D . they operate at a lower speed
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A diesel engine which is rated for normal operation at a crankshaft speed of 800 RPM, is commonly classed as a （）.
A . slow-speed diesel
B . medium-speed diesel
C . high-speed diesel
D . constant-speed diesel
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At least （） cylinders in four-stroke engine will be configured to ensure that the engine can be started with the crankshaft at whatever position.
A . 6
B . 2
C . 12
D . 8
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The term diesel engine scavenging means（）
A . delivering more air into the cylinder than it would normally receive during an ordinary charging process
B . forcing the products of combustion out of the cylinder with the fresh air charge
C . collecting the air charge at the cleaner
D . combustion and expansion of hot ga
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Critical speed in diesel engines occurs when engine torque pulsations become （）
A . opposed to the crankshaft rocking couple
B . resonant with the crankshaft natural frequency
C . critical fore and aft crankshaft vibrations
D . horizontal whipping motions of the crankshaft
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An increase in load on a diesel engine results in （） of speed of the crankshaft.
A . a reduction
B . an increase
C . an outing
D . a downward
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All diesel engines are classified as（）.
A . four cycle
B . compression ignition
C . vacuum ignition
D . external combustio
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Diesel oil may be used to cool （） of a diesel engine.
A . cylinders
B . exhaust valves
C . pistons
D . fuel valve
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The highest loads applied to the diesel engine crankshaft main bearings are （）
A . axial loads
B . firing loads
C . inertia loads
D . centripetal load
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（） of an engine crankshaft can be detected by measuring deflections of crank webs for each unit of the engine.
A . Misalignment
B . Length
C . Strength
D . Stresse
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On a large diesel engine installation, crankshaft axial alignment is maintained by the （）
A . piston rod guides
B . engine thrust bearing
C . crosshead bearing
D . main shaft flexible coupling
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When a crankshaft （） outside the engine, it should be carefully supported in a manner which will avoid imposing high bending moments on it.
A . has to be handled
B . may be handled
C . has being handled
D . will be handling
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Diesel engine mufflers or silencers reduce the engine exhaust noise by （）
A . passing the exhaust through long head pipes
B . diffusing exhaust vibrations through activated carbon baffles
C . increasing the exhaust gas velocity
D . reducing the exhaust gas velocity
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What is the speed of the crankshaft in a four-stroke/cycle engine when the camshaft is turning at 750 rpm?（）
A . 375 RPM
B . 500 RPM
C . 750 RPM
D . 1500 RPM
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In four-stroke diesel engine, the cycle of events is completed in （) of crankshaft.A.one
In four-stroke diesel engine, the cycle of events is completed in () of crankshaft.
A.one revolution
B.two revolutions
C.four revolutions
