单项选择题

Wristpin bearings are difficult to lubricate because of their oscillating motion and（）

A.their free-floating design
B.their relatively small size
C.the reciprocating motion of the piston
D.their position in the lubrication system

点击查看答案&解析

上一题目录下一题

相关考题

单项选择题

Internal combustion engine crankcase vent outlets must be equipped with （）

A.hinged rain guards
B.corrosion resistant flame screens
C.dipsticks for measuring oil levels
D.crankcase ventilation fans

单项选择题

The interior of some diesel engine saltwater heat exchangers are protected from corrosion by the use of（）

A.aluminum plates
B.lead cathodes
C.copper baffle plates
D.sacrificial zincs

单项选择题

Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because （）

A.bearing pressure in a four-stroke\cycle acting single diesel engine is continually reversed
B.bearing pressure in a two-stroke\cycle single acting diesel engine is continually reversed
C.the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine
D.two-stoke/cycle diesel engines require more complicated lubrication piping