A. provide a reservoir for cylinder lubrication
B. pump oil into the combustion space for cylinder cooling
C. prevent excessive lubricating oil consumption
D. allow hydraulic oil film formation on the cylinder
[单选] The main purpose of the piston oil scraper rings is to （）A. seal the space
[单选题]The main purpose of the piston oil scraper rings is to （）.A . seal the space between the piston and the linerB . reduce the amount of lube oil burned in the combustion chamberC . transmit heat from the piston to the cylinder linerD . damp out fluctua
[单选题]The piston rings are manufactured with a diameter （） the bore of the cylinder.A . larger thanB . smaller thanC . equal toD . none of the above
[单选题]The piston rings if found worn out （） and supplied by shipchandler.A . must replaceB . must to be equippedC . has to be repairedD . have to be renewed
[单选题]Among the rings of a piston the （） one is subjected to the greatest load and temperature.A . bottomB . middleC . topD . none of the above
[单选题]These piston rings are so badly worn that they must be （）.A . renewedB . weldedC . machinedD . chromium-plated
[单选题]For a diesel engine, when the piston is at the （）, the clearance volume is the largest.A . TDCB . DTCC . BDCD . DBC
[单选题]The purpose of the flywheel of a diesel engine is to （）.A . counterbalance the crank throws on the crankshaftB . keep the engine running smoothly between power strokeC . provide a belt-driving surface for the operation of auxiliary machineryD . preve
[单选题]The upper piston rings m large, slow-speed, two-stroke/cycle diesel engines are most effectively lubricated by oil ____.A．fed from mechanical lubricatorsB．thrown off from the main bearingsC．supplied from wick fed drip lubricatorsD．flow from a centrif
[单选题]The film of oil between the rings and the liner is not only essential for the lubrication but also plays an important part in achieving （）.A . an oil sealB . removing heatC . a gas sealD . cooling the pisto