单项选择题
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)
As for a hydraulic single action vane pump, the inner w...
单项选择题As for a hydraulic single action vane pump, the inner wall of the stator is usually of （） shape.
A.circular B.elliptical C.rectangular D.hexagon
Throttling in the （） line of a centrifugal pump involve...
单项选择题Throttling in the （） line of a centrifugal pump involves the risk of the pump cavitation.
A.suction B.exhaust C.pressure D.discharge
A positive displacement pump is that where the volume o...
单项选择题A positive displacement pump is that where the volume of the pump chamber is alternately increased to （） and then decreased to （）.
A.draw the liquid in；force the liquid out B.force the liquid out；draw the liquid in C.suction；draw D.deliver；outlet
