A.the slewing motor
B.the luffing motor
C.the hoisting motor
D.none of the above
您可能感興趣的試卷
你可能感興趣的試題
A.unusual vibration
B.excessive worn parts
C.abnormal pressure
D.any of the above
A.Relief valve
B.Direction control valve
C.Stop valve
D.Pressure control valve
A.flow of oil
B.pressure of oil
C.A and B
D.temperature of oil
A.Relief valves
B.Check valves
C.Safety valves
D.Reducing valve
A.Hydraulic pumps
B.Valve
C.Hydraulic cylinders
D.Hydraulic motors
最新試題
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
Which of the listed pumps is NOT a positive displacement pump?（）
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.
The usual symptoms of cavitation in a centrifugal pump is （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）