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 vane pump belongs to （） according to its working principle.
英译汉：wind vane
As for a hydraulic single action vane pump, the inner wall of the stator is usually of （） shape.
The gear, screw, and vane pumps are all classified as （）.
With reference to a rotary vane steering gear system, which one of the following statements is true?（）
The gear, screw, and vane pumps are all classified as （）.
A vane pump belongs to （） according to its working principle.
With reference to a rotary vane steering gear system, which one of the following statements is true?（）
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
