As for a hydraulic vane pump, which of the following is in contact with the vanes during working: （）
(1)the rotor
(2)the pump shaft
(3)the external surface of the housing
A.(1) only
B.(2) only
C.(1) and (2)
D.(1),(2)and(3)
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A.circular
B.elliptical
C.rectangular
D.hexagon
A.suction
B.exhaust
C.pressure
D.discharge
A.draw the liquid in；force the liquid out
B.force the liquid out；draw the liquid in
C.suction；draw
D.deliver；outlet
A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is tree
Which of the following pumps are self-priming, and can deal with liquid from a level below the pump? （）
(1) reciprocating
(2) rotary
(3) centrifugal
A.(1)only
B.(1)and (2)
C.(1),(2)and(3)
D.(2)and(3)
最新試題
Which of the listed pumps is NOT a positive displacement pump?（）
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If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
The rate of heat transfer from a hot region to a cold region is affected most by the （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
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