更多"The sealing function of the piston "的相关试题:
[单项选择]Black areas on the sealing surfaces of piston rings indicate（）
A. lube oil pumping
B. rotating rings
C. gas pressure behind the ring
D. passage of hot gases
[单项选择]The piston ring grooves for a standard engine are （）
A. chromium-plate against wear
B. anti-corrosion treated
C. white metal lined against wear
D. flame hardened against wear
[单项选择]If the piston ring gap remains insufficient when installing new rings, youshould（）
A. install oversized rings
B. hone the cylinder liner to allow ring installation
C. compress the rings tighter with a compressing tool
D. file the ends of the rings
[单项选择]Excessive piston ring wear in a diesel engine will cause（）
A. high lube oil viscosity
B. increased lube oil consumption
C. low lube oil temperatures
D. high firing pressures
[单项选择]For any piston ring to operate smoothly without scuffing ,the ring must be （）.
A. of a material harder than the cylinder liner
B. properly lubricated
C. prevented from compressing
D. prevented from rotating during engine operation
[单项选择]A diesel engine piston ring face is in direct contact with the （）.
A. top of the ring groove
B. cylinder liner oil film
C. bottom of the ring groove
D. back of the ring groove
[单项选择]Diesel engine piston ring blow-by is usually caused by excessive ring clearance at the ring（）
A. back
B. side
C. gap
D. bottom
[单项选择]If the back clearance of a piston ring is excessive,（）
A. compression pressure in the cylinder will be higher
B. carbon will accumulate behind the ring
C. combustion gases will penetrate beneath the ring land
D. piston side thrust will be increased
[单项选择]The top piston ring is plasma coated to give the lowest wear rate to reach the goal of two-years’ with sufficient margin（）
A. TBO
B. CEO
C. CFO
D. MCR
[单项选择]The function of the piston compression rings used in a diesel engine is to （）
A. seal the space between the piston and liner
B. transmit heat from the piston to the cylinder liner
C. reduce the amount of combustion gas blow-by
D. all of the above
[单项选择]The main function of piston compression rings is to （）
A. prevent excessive cylinder liner wear
B. reduce friction losses in the engine
C. seal the space between the piston and the liner
D. limit upward flow of lube oil into the combustion space
[单项选择]The function of diesel engine piston compression rings is to （）.
A. prevent piston side thrust
B. prevent engine friction losses
C. transmit heat from the piston to the cylinder liner
D. remove oil from the cylinder combustion space
[单项选择]The lowest ring of a piston is （）.
A. a coil spring
B. a sealing ring
C. an oil distributor ring
D. main seal ring
[单项选择](Piston area)X(Piston stroke)K(numbers of the cylinders)=engine（）
A. brake horsepower
B. displacement
C. cylinder volume
D. cylinder clearance
[单项选择]Abnormal crankpin bearing and piston skirt surface wear indicate（）
A. a restricted air intake
B. a clogged connecting rod oil passage
C. incorrect connecting rod alignment
D. high cylinder firing temperatures
[单项选择]Piston cooling fins are located（）
A. atop the piston crown
B. beneath the piston crown
C. at the base of the piston skirt
D. inside the cylinder liner cooling water jacket
[单项选择]Insufficient end clearance on newly fitted piston rings in a diesel enginewill cause the rings to（）
A. jam in the most worn part of the cylinder when the rings expand
B. break in the most worn part of the cylinder when the rings expand
C. wear eccentrically on the side opposite the end gap
D. overheat and jam at the top center on the combustion stroke
[单项选择]Broken piston rings manifest themselves during the scavenge port inspection by（）
A. Lack of elastic tension, when the rings are pressed into the groove by means of a stick
B. Blackish appearance
C. Fractured rings and missing rings
D. all off the above
[单项选择]The piston supporting body is mainly subjected to （） stress.
A. pushing
B. centrifugal
C. stretch
D. compressive
